B: Do not revalidate auth on password reset

rsconcept/backend/requirements-dev-lock.txt

@@ -1,5 +1,5 @@
-tzdata==2024.2
-Django==5.1.3
+tzdata==2025.1
+Django==5.1.5
 djangorestframework==3.15.2
 django-cors-headers==4.6.0
 django-filter==24.3
@@ -12,9 +12,9 @@ pyconcept==0.1.12
 
 psycopg2-binary==2.9.10
 gunicorn==23.0.0
-djangorestframework-stubs==3.15.1
+djangorestframework-stubs==3.15.2
 django-extensions==3.2.3
-django-stubs==5.1.1
+django-stubs==5.1.2
 mypy==1.13.0
-pylint==3.3.2
-coverage==7.6.8
+pylint==3.3.3
+coverage==7.6.10

rsconcept/backend/requirements.txt

@@ -1,5 +1,5 @@
-tzdata==2024.2
-Django==5.1.3
+tzdata==2025.1
+Django==5.1.5
 djangorestframework==3.15.2
 django-cors-headers==4.6.0
 django-filter==24.3

rsconcept/frontend/package.json

@@ -14,8 +14,8 @@
   "dependencies": {
     "@dagrejs/dagre": "^1.1.4",
     "@lezer/lr": "^1.4.2",
-    "@tanstack/react-query": "^5.64.1",
-    "@tanstack/react-query-devtools": "^5.64.1",
+    "@tanstack/react-query": "^5.64.2",
+    "@tanstack/react-query-devtools": "^5.64.2",
     "@tanstack/react-table": "^8.20.6",
     "@uiw/codemirror-themes": "^4.23.7",
     "@uiw/react-codemirror": "^4.23.7",
@@ -28,9 +28,9 @@
     "react-dom": "^19.0.0",
     "react-error-boundary": "^5.0.0",
     "react-icons": "^5.4.0",
-    "react-intl": "7.0.4",
-    "react-router": "^7.1.2",
-    "react-select": "^5.9.0",
+    "react-intl": "^7.1.5",
+    "react-router": "^7.1.3",
+    "react-select": "^5.10.0",
     "react-tabs": "^6.1.0",
     "react-toastify": "^11.0.3",
     "react-tooltip": "^5.28.0",
@@ -41,17 +41,17 @@
   },
   "devDependencies": {
     "@lezer/generator": "^1.7.2",
-    "@playwright/test": "^1.49.1",
+    "@playwright/test": "^1.50.0",
     "@types/jest": "^29.5.14",
-    "@types/node": "^22.10.7",
-    "@types/react": "^19.0.7",
+    "@types/node": "^22.10.10",
+    "@types/react": "^19.0.8",
     "@types/react-dom": "^19.0.3",
     "@typescript-eslint/eslint-plugin": "^8.0.1",
     "@typescript-eslint/parser": "^8.0.1",
     "@vitejs/plugin-react": "^4.3.4",
     "autoprefixer": "^10.4.20",
     "babel-plugin-react-compiler": "^19.0.0-beta-37ed2a7-20241206",
-    "eslint": "^9.18.0",
+    "eslint": "^9.19.0",
     "eslint-plugin-react": "^7.37.4",
     "eslint-plugin-react-compiler": "^19.0.0-beta-37ed2a7-20241206",
     "eslint-plugin-react-hooks": "^5.1.0",
@@ -62,8 +62,8 @@
     "tailwindcss": "^3.4.17",
     "ts-jest": "^29.2.5",
     "typescript": "^5.7.3",
-    "typescript-eslint": "^8.20.0",
-    "vite": "^6.0.7"
+    "typescript-eslint": "^8.21.0",
+    "vite": "^6.0.11"
   },
   "overrides": {
     "react": "^19.0.0"

rsconcept/frontend/playwright.config.ts

@@ -4,7 +4,7 @@ export default defineConfig({
   testDir: 'tests',
   forbidOnly: !!process.env.CI,
   retries: process.env.CI ? 2 : 0,
-  reporter: 'html',
+  reporter: 'list',
   projects: [
     {
       name: 'Desktop Chrome',

rsconcept/frontend/src/app/ApplicationLayout.tsx

@@ -1,16 +1,30 @@
 import { Suspense } from 'react';
+import { ErrorBoundary } from 'react-error-boundary';
 import { Outlet } from 'react-router';
 
 import ConceptToaster from '@/app/ConceptToaster';
 import Footer from '@/app/Footer';
 import Navigation from '@/app/Navigation';
 import Loader from '@/components/ui/Loader';
-import { NavigationState } from '@/context/NavigationContext';
+import ModalLoader from '@/components/ui/ModalLoader';
 import { useAppLayoutStore, useMainHeight, useViewportHeight } from '@/stores/appLayout';
 import { globals } from '@/utils/constants';
 
+import ErrorFallback from './ErrorFallback';
 import { GlobalDialogs } from './GlobalDialogs';
 import { GlobalTooltips } from './GlobalTooltips';
+import { NavigationState } from './Navigation/NavigationContext';
+
+const resetState = () => {
+  console.log('Resetting state after error fallback');
+};
+
+const logError = (error: Error, info: { componentStack?: string | null | undefined }) => {
+  console.log('Error fallback: ' + error.message);
+  if (info.componentStack) {
+    console.log('Component stack: ' + info.componentStack);
+  }
+};
 
 function ApplicationLayout() {
   const mainHeight = useMainHeight();
@@ -20,9 +34,8 @@ function ApplicationLayout() {
   const noNavigation = useAppLayoutStore(state => state.noNavigation);
   const noFooter = useAppLayoutStore(state => state.noFooter);
 
-  // TODO: prefetch data
-
   return (
+    <ErrorBoundary FallbackComponent={ErrorFallback} onError={logError} onReset={resetState}>
       <NavigationState>
         <div className='min-w-[20rem] antialiased h-full max-w-[120rem] mx-auto'>
           <ConceptToaster
@@ -33,7 +46,9 @@ function ApplicationLayout() {
             pauseOnFocusLoss={false}
           />
 
+          <Suspense fallback={<ModalLoader />}>
             <GlobalDialogs />
+          </Suspense>
           <GlobalTooltips />
 
           <Navigation />
@@ -54,6 +69,7 @@ function ApplicationLayout() {
           </div>
         </div>
       </NavigationState>
+    </ErrorBoundary>
   );
 }
 

rsconcept/frontend/src/app/ErrorFallback.tsx

@@ -1,12 +1,12 @@
 import { type FallbackProps } from 'react-error-boundary';
 
-import InfoError from '../components/info/InfoError';
-import Button from '../components/ui/Button';
+import InfoError from '@/components/info/InfoError';
+import Button from '@/components/ui/Button';
 
 function ErrorFallback({ error, resetErrorBoundary }: FallbackProps) {
   return (
-    <div className='flex flex-col gap-3 items-center antialiased' role='alert'>
-      <h1>Что-то пошло не так!</h1>
+    <div className='flex flex-col gap-3 my-3 items-center antialiased' role='alert'>
+      <h1 className='my-2'>Что-то пошло не так!</h1>
       <Button onClick={resetErrorBoundary} text='Попробовать еще раз' />
       <InfoError error={error as Error} />
     </div>

rsconcept/frontend/src/app/Footer.tsx

@@ -1,9 +1,8 @@
 import clsx from 'clsx';
 
+import TextURL from '@/components/ui/TextURL';
 import { external_urls } from '@/utils/constants';
 
-import TextURL from '../components/ui/TextURL';
-
 function Footer() {
   return (
     <footer

rsconcept/frontend/src/app/GlobalDialogs.tsx

@@ -1,31 +1,34 @@
 'use client';
 
-import DlgChangeInputSchema from '@/dialogs/DlgChangeInputSchema';
-import DlgChangeLocation from '@/dialogs/DlgChangeLocation';
-import DlgCloneLibraryItem from '@/dialogs/DlgCloneLibraryItem';
-import DlgCreateCst from '@/dialogs/DlgCreateCst';
-import DlgCreateOperation from '@/dialogs/DlgCreateOperation';
-import DlgCreateVersion from '@/dialogs/DlgCreateVersion';
-import DlgCstTemplate from '@/dialogs/DlgCstTemplate';
-import DlgDeleteCst from '@/dialogs/DlgDeleteCst';
-import DlgDeleteOperation from '@/dialogs/DlgDeleteOperation';
-import DlgEditEditors from '@/dialogs/DlgEditEditors';
-import DlgEditOperation from '@/dialogs/DlgEditOperation';
-import DlgEditReference from '@/dialogs/DlgEditReference';
-import DlgEditVersions from '@/dialogs/DlgEditVersions';
-import DlgEditWordForms from '@/dialogs/DlgEditWordForms';
-import DlgGraphParams from '@/dialogs/DlgGraphParams';
-import DlgInlineSynthesis from '@/dialogs/DlgInlineSynthesis';
-import DlgRelocateConstituents from '@/dialogs/DlgRelocateConstituents';
-import DlgRenameCst from '@/dialogs/DlgRenameCst';
-import DlgShowAST from '@/dialogs/DlgShowAST';
-import DlgShowQR from '@/dialogs/DlgShowQR';
-import DlgShowTypeGraph from '@/dialogs/DlgShowTypeGraph';
-import DlgSubstituteCst from '@/dialogs/DlgSubstituteCst';
-import DlgUploadRSForm from '@/dialogs/DlgUploadRSForm';
+import React from 'react';
+
 import { DialogType } from '@/models/miscellaneous';
 import { useDialogsStore } from '@/stores/dialogs';
 
+const DlgChangeInputSchema = React.lazy(() => import('@/dialogs/DlgChangeInputSchema'));
+const DlgChangeLocation = React.lazy(() => import('@/dialogs/DlgChangeLocation'));
+const DlgCloneLibraryItem = React.lazy(() => import('@/dialogs/DlgCloneLibraryItem'));
+const DlgCreateCst = React.lazy(() => import('@/dialogs/DlgCreateCst'));
+const DlgCreateOperation = React.lazy(() => import('@/dialogs/DlgCreateOperation'));
+const DlgCreateVersion = React.lazy(() => import('@/dialogs/DlgCreateVersion'));
+const DlgCstTemplate = React.lazy(() => import('@/dialogs/DlgCstTemplate'));
+const DlgDeleteCst = React.lazy(() => import('@/dialogs/DlgDeleteCst'));
+const DlgDeleteOperation = React.lazy(() => import('@/dialogs/DlgDeleteOperation'));
+const DlgEditEditors = React.lazy(() => import('@/dialogs/DlgEditEditors'));
+const DlgEditOperation = React.lazy(() => import('@/dialogs/DlgEditOperation'));
+const DlgEditReference = React.lazy(() => import('@/dialogs/DlgEditReference'));
+const DlgEditVersions = React.lazy(() => import('@/dialogs/DlgEditVersions'));
+const DlgEditWordForms = React.lazy(() => import('@/dialogs/DlgEditWordForms'));
+const DlgGraphParams = React.lazy(() => import('@/dialogs/DlgGraphParams'));
+const DlgInlineSynthesis = React.lazy(() => import('@/dialogs/DlgInlineSynthesis'));
+const DlgRelocateConstituents = React.lazy(() => import('@/dialogs/DlgRelocateConstituents'));
+const DlgRenameCst = React.lazy(() => import('@/dialogs/DlgRenameCst'));
+const DlgShowAST = React.lazy(() => import('@/dialogs/DlgShowAST'));
+const DlgShowQR = React.lazy(() => import('@/dialogs/DlgShowQR'));
+const DlgShowTypeGraph = React.lazy(() => import('@/dialogs/DlgShowTypeGraph'));
+const DlgSubstituteCst = React.lazy(() => import('@/dialogs/DlgSubstituteCst'));
+const DlgUploadRSForm = React.lazy(() => import('@/dialogs/DlgUploadRSForm'));
+
 export const GlobalDialogs = () => {
   const active = useDialogsStore(state => state.active);
 

rsconcept/frontend/src/app/GlobalProviders.tsx

@@ -2,47 +2,21 @@
 
 import { QueryClientProvider } from '@tanstack/react-query';
 import { ReactQueryDevtools } from '@tanstack/react-query-devtools';
-import { ErrorBoundary } from 'react-error-boundary';
 import { IntlProvider } from 'react-intl';
 
 import { queryClient } from '@/backend/queryClient';
-import { GlobalOssState } from '@/context/GlobalOssContext';
-import { LibraryState } from '@/context/LibraryContext';
-
-import ErrorFallback from './ErrorFallback';
-
-const resetState = () => {
-  console.log('Resetting state after error fallback');
-};
-
-const logError = (error: Error, info: { componentStack?: string | null | undefined }) => {
-  console.log('Error fallback: ' + error.message);
-  if (info.componentStack) {
-    console.log('Component stack: ' + info.componentStack);
-  }
-};
 
 // prettier-ignore
 function GlobalProviders({ children }: React.PropsWithChildren) {
   return (
-  <ErrorBoundary
-    FallbackComponent={ErrorFallback}
-    onReset={resetState}
-    onError={logError}
-  >
   <IntlProvider locale='ru' defaultLocale='ru'>
   <QueryClientProvider client={queryClient}>
-  <LibraryState>
-  <GlobalOssState>
   
     <ReactQueryDevtools initialIsOpen={false} />
     {children}
   
-  </GlobalOssState>
-  </LibraryState>
   </QueryClientProvider>
-  </IntlProvider>
-  </ErrorBoundary>);
+  </IntlProvider>);
 }
 
 export default GlobalProviders;

rsconcept/frontend/src/app/Navigation/Navigation.tsx

@@ -1,8 +1,8 @@
 import clsx from 'clsx';
 
+import { useConceptNavigation } from '@/app/Navigation/NavigationContext';
 import { IconLibrary2, IconManuals, IconNewItem2 } from '@/components/Icons';
 import { CProps } from '@/components/props';
-import { useConceptNavigation } from '@/context/NavigationContext';
 import useWindowSize from '@/hooks/useWindowSize';
 import { useAppLayoutStore } from '@/stores/appLayout';
 import { PARAMETER } from '@/utils/constants';
@@ -27,7 +27,7 @@ function Navigation() {
   return (
     <nav
       className={clsx(
-        'z-navigation', // prettier: split lines
+        'z-navigation', //
         'sticky top-0 left-0 right-0',
         'select-none',
         'bg-prim-100'
@@ -36,7 +36,7 @@ function Navigation() {
       <ToggleNavigation />
       <div
         className={clsx(
-          'pl-2 pr-[1.5rem] sm:pr-[0.9rem] h-[3rem]', // prettier: split lines
+          'pl-2 pr-[1.5rem] sm:pr-[0.9rem] h-[3rem]', //
           'flex',
           'cc-shadow-border'
         )}

rsconcept/frontend/src/app/Navigation/NavigationButton.tsx

@@ -29,7 +29,7 @@ function NavigationButton({
       data-tooltip-hidden={hideTitle}
       onClick={onClick}
       className={clsx(
-        'mr-1 h-full', // prettier: split lines
+        'mr-1 h-full', //
         'flex items-center gap-1',
         'clr-btn-nav cc-animate-color duration-500',
         'rounded-xl',

rsconcept/frontend/src/app/Navigation/UserButton.tsx

@@ -10,9 +10,9 @@ interface UserButtonProps {
 }
 
 function UserButton({ onLogin, onClickUser }: UserButtonProps) {
-  const { user } = useAuthSuspense();
+  const { user, isAnonymous } = useAuthSuspense();
   const adminMode = usePreferencesStore(state => state.adminMode);
-  if (!user) {
+  if (isAnonymous) {
     return (
       <NavigationButton
         className='cc-fade-in'

rsconcept/frontend/src/app/Navigation/UserDropdown.tsx

@@ -1,4 +1,5 @@
-import { useAuth } from '@/backend/auth/useAuth';
+import { useConceptNavigation } from '@/app/Navigation/NavigationContext';
+import { useAuthSuspense } from '@/backend/auth/useAuth';
 import { useLogout } from '@/backend/auth/useLogout';
 import {
   IconAdmin,
@@ -17,7 +18,6 @@ import {
 import { CProps } from '@/components/props';
 import Dropdown from '@/components/ui/Dropdown';
 import DropdownButton from '@/components/ui/DropdownButton';
-import { useConceptNavigation } from '@/context/NavigationContext';
 import { usePreferencesStore } from '@/stores/preferences';
 
 import { urls } from '../urls';
@@ -29,7 +29,7 @@ interface UserDropdownProps {
 
 function UserDropdown({ isOpen, hideDropdown }: UserDropdownProps) {
   const router = useConceptNavigation();
-  const { user } = useAuth();
+  const { user } = useAuthSuspense();
   const { logout } = useLogout();
 
   const darkMode = usePreferencesStore(state => state.darkMode);
@@ -77,7 +77,7 @@ function UserDropdown({ isOpen, hideDropdown }: UserDropdownProps) {
   return (
     <Dropdown className='mt-[1.5rem] min-w-[18ch] max-w-[12rem]' stretchLeft isOpen={isOpen}>
       <DropdownButton
-        text={user?.username}
+        text={user.username}
         title='Профиль пользователя'
         icon={<IconUser size='1rem' />}
         onClick={navigateProfile}
@@ -94,7 +94,7 @@ function UserDropdown({ isOpen, hideDropdown }: UserDropdownProps) {
         title='Отображение иконок подсказок'
         onClick={toggleShowHelp}
       />
-      {user?.is_staff ? (
+      {user.is_staff ? (
         <DropdownButton
           text={adminMode ? 'Админ: Вкл' : 'Админ: Выкл'}
           icon={adminMode ? <IconAdmin size='1rem' /> : <IconAdminOff size='1rem' />}
@@ -102,7 +102,7 @@ function UserDropdown({ isOpen, hideDropdown }: UserDropdownProps) {
           onClick={toggleAdminMode}
         />
       ) : null}
-      {user?.is_staff ? (
+      {user.is_staff ? (
         <DropdownButton
           text='REST API' // prettier: split-line
           icon={<IconRESTapi size='1rem' />}
@@ -110,7 +110,7 @@ function UserDropdown({ isOpen, hideDropdown }: UserDropdownProps) {
           onClick={gotoRestApi}
         />
       ) : null}
-      {user?.is_staff ? (
+      {user.is_staff ? (
         <DropdownButton
           text='База данных' // prettier: split-line
           icon={<IconDatabase size='1rem' />}
@@ -124,7 +124,7 @@ function UserDropdown({ isOpen, hideDropdown }: UserDropdownProps) {
           onClick={gotoIcons}
         />
       ) : null}
-      {user?.is_staff ? (
+      {user.is_staff ? (
         <DropdownButton
           text='Структура БД' // prettier: split-line
           icon={<IconDBStructure size='1rem' />}

rsconcept/frontend/src/app/Navigation/UserMenu.tsx

@@ -1,7 +1,7 @@
 import { Suspense } from 'react';
 
+import { useConceptNavigation } from '@/app/Navigation/NavigationContext';
 import Loader from '@/components/ui/Loader';
-import { useConceptNavigation } from '@/context/NavigationContext';
 import useDropdown from '@/hooks/useDropdown';
 
 import { urls } from '../urls';

rsconcept/frontend/src/app/Router.tsx

@@ -1,30 +1,27 @@
-import React from 'react';
 import { createBrowserRouter } from 'react-router';
 
+import { prefetchAuth } from '@/backend/auth/useAuth';
+import { prefetchLibrary } from '@/backend/library/useLibrary';
+import { prefetchOSS } from '@/backend/oss/useOSS';
+import { prefetchRSForm } from '@/backend/rsform/useRSForm';
+import { prefetchProfile } from '@/backend/users/useProfile';
+import { prefetchUsers } from '@/backend/users/useUsers';
+import Loader from '@/components/ui/Loader';
 import CreateItemPage from '@/pages/CreateItemPage';
 import HomePage from '@/pages/HomePage';
-import LibraryPage from '@/pages/LibraryPage';
 import LoginPage from '@/pages/LoginPage';
 import NotFoundPage from '@/pages/NotFoundPage';
-import OssPage from '@/pages/OssPage';
-import RSFormPage from '@/pages/RSFormPage';
 
 import ApplicationLayout from './ApplicationLayout';
 import { routes } from './urls';
 
-const UserProfilePage = React.lazy(() => import('@/pages/UserProfilePage'));
-const RestorePasswordPage = React.lazy(() => import('@/pages/RestorePasswordPage'));
-const PasswordChangePage = React.lazy(() => import('@/pages/PasswordChangePage'));
-const RegisterPage = React.lazy(() => import('@/pages/RegisterPage'));
-const ManualsPage = React.lazy(() => import('@/pages/ManualsPage'));
-const IconsPage = React.lazy(() => import('@/pages/IconsPage'));
-const DatabaseSchemaPage = React.lazy(() => import('@/pages/DatabaseSchemaPage'));
-
 export const Router = createBrowserRouter([
   {
     path: '/',
     element: <ApplicationLayout />,
     errorElement: <NotFoundPage />,
+    loader: prefetchAuth,
+    hydrateFallbackElement: <Loader />,
     children: [
       {
         path: '',
@@ -40,23 +37,25 @@ export const Router = createBrowserRouter([
       },
       {
         path: routes.signup,
-        element: <RegisterPage />
+        lazy: () => import('@/pages/RegisterPage')
       },
       {
         path: routes.profile,
-        element: <UserProfilePage />
+        loader: prefetchProfile,
+        lazy: () => import('@/pages/UserProfilePage')
       },
       {
         path: routes.restore_password,
-        element: <RestorePasswordPage />
+        lazy: () => import('@/pages/RestorePasswordPage')
       },
       {
         path: routes.password_change,
-        element: <PasswordChangePage />
+        lazy: () => import('@/pages/PasswordChangePage')
       },
       {
         path: routes.library,
-        element: <LibraryPage />
+        loader: () => Promise.allSettled([prefetchLibrary(), prefetchUsers()]),
+        lazy: () => import('@/pages/LibraryPage')
       },
       {
         path: routes.create_schema,
@@ -64,24 +63,37 @@ export const Router = createBrowserRouter([
       },
       {
         path: `${routes.rsforms}/:id`,
-        element: <RSFormPage />
+        loader: data => prefetchRSForm(parseRSFormURL(data.params.id, data.request.url)),
+        lazy: () => import('@/pages/RSFormPage')
       },
       {
         path: `${routes.oss}/:id`,
-        element: <OssPage />
+        loader: data => prefetchOSS(parseOssURL(data.params.id)),
+        lazy: () => import('@/pages/OssPage')
       },
       {
         path: routes.manuals,
-        element: <ManualsPage />
+        lazy: () => import('@/pages/ManualsPage')
       },
       {
         path: `${routes.icons}`,
-        element: <IconsPage />
+        lazy: () => import('@/pages/IconsPage')
       },
       {
         path: `${routes.database_schema}`,
-        element: <DatabaseSchemaPage />
+        lazy: () => import('@/pages/DatabaseSchemaPage')
       }
     ]
   }
 ]);
+
+// ======= Internals =========
+function parseRSFormURL(id: string | undefined, url: string) {
+  const params = new URLSearchParams(url.split('?')[1]);
+  const version = params.get('v');
+  return { itemID: id ? Number(id) : undefined, version: version ? Number(version) : undefined };
+}
+
+function parseOssURL(id: string | undefined) {
+  return { itemID: id ? Number(id) : undefined };
+}

rsconcept/frontend/src/backend/apiConfiguration.ts

@@ -1,25 +0,0 @@
-/**
- * Module: communication setup.
- */
-import axios from 'axios';
-
-import { buildConstants } from '@/utils/buildConstants';
-
-const defaultOptions = {
-  xsrfCookieName: 'csrftoken',
-  xsrfHeaderName: 'x-csrftoken',
-  baseURL: `${buildConstants.backend}`,
-  withCredentials: true
-};
-
-export const axiosInstance = axios.create(defaultOptions);
-axiosInstance.interceptors.request.use(config => {
-  const token = document.cookie
-    .split('; ')
-    .find(row => row.startsWith('csrftoken='))
-    ?.split('=')[1];
-  if (token) {
-    config.headers['x-csrftoken'] = token;
-  }
-  return config;
-});

rsconcept/frontend/src/backend/apiTransport.ts

@@ -1,115 +1,132 @@
 /**
- * Module: generic API for backend REST communications.
+ * Module: generic API for backend REST communications using axios library.
  */
+import axios from 'axios';
 import { AxiosError, AxiosRequestConfig } from 'axios';
 import { toast } from 'react-toastify';
 
-import { ErrorData } from '@/components/info/InfoError';
+import { buildConstants } from '@/utils/buildConstants';
 import { extractErrorMessage } from '@/utils/utils';
 
-import { axiosInstance } from './apiConfiguration';
+const defaultOptions = {
+  xsrfCookieName: 'csrftoken',
+  xsrfHeaderName: 'x-csrftoken',
+  baseURL: `${buildConstants.backend}`,
+  withCredentials: true
+};
+
+const axiosInstance = axios.create(defaultOptions);
+axiosInstance.interceptors.request.use(config => {
+  const token = document.cookie
+    .split('; ')
+    .find(row => row.startsWith('csrftoken='))
+    ?.split('=')[1];
+  if (token) {
+    config.headers['x-csrftoken'] = token;
+  }
+  return config;
+});
 
 // ================ Data transfer types ================
 export type DataCallback<ResponseData = undefined> = (data: ResponseData) => void;
 
 export interface IFrontRequest<RequestData, ResponseData> {
   data?: RequestData;
-  onSuccess?: DataCallback<ResponseData>;
-  onError?: (error: ErrorData) => void;
-  setLoading?: (loading: boolean) => void;
-  showError?: boolean;
+  successMessage?: string | ((data: ResponseData) => string);
 }
 
-export interface FrontPush<DataType> extends IFrontRequest<DataType, undefined> {
-  data: DataType;
-}
-export interface FrontPull<DataType> extends IFrontRequest<undefined, DataType> {
-  onSuccess: DataCallback<DataType>;
-}
-
-export interface FrontExchange<RequestData, ResponseData> extends IFrontRequest<RequestData, ResponseData> {
-  data: RequestData;
-  onSuccess: DataCallback<ResponseData>;
-}
-
-export interface FrontAction extends IFrontRequest<undefined, undefined> {}
-
 export interface IAxiosRequest<RequestData, ResponseData> {
   endpoint: string;
-  request: IFrontRequest<RequestData, ResponseData>;
+  request?: IFrontRequest<RequestData, ResponseData>;
   options?: AxiosRequestConfig;
 }
 
+export interface IAxiosGetRequest {
+  endpoint: string;
+  options?: AxiosRequestConfig;
+  signal?: AbortSignal;
+}
+
 // ================ Transport API calls ================
-export function AxiosGet<ResponseData>({ endpoint, request, options }: IAxiosRequest<undefined, ResponseData>) {
-  request.setLoading?.(true);
-  axiosInstance
+export function axiosGet<ResponseData>({ endpoint, options }: IAxiosGetRequest) {
+  return axiosInstance
     .get<ResponseData>(endpoint, options)
-    .then(response => {
-      request.setLoading?.(false);
-      request.onSuccess?.(response.data);
-    })
+    .then(response => response.data)
     .catch((error: Error | AxiosError) => {
-      request.setLoading?.(false);
-      if (request.showError) toast.error(extractErrorMessage(error));
-      request.onError?.(error);
+      toast.error(extractErrorMessage(error));
+      console.error(error);
+      throw error;
     });
 }
 
-export function AxiosPost<RequestData, ResponseData>({
+export function axiosPost<RequestData, ResponseData = void>({
   endpoint,
   request,
   options
 }: IAxiosRequest<RequestData, ResponseData>) {
-  request.setLoading?.(true);
-  axiosInstance
-    .post<ResponseData>(endpoint, request.data, options)
+  return axiosInstance
+    .post<ResponseData>(endpoint, request?.data, options)
     .then(response => {
-      request.setLoading?.(false);
-      request.onSuccess?.(response.data);
-    })
-    .catch((error: Error | AxiosError) => {
-      request.setLoading?.(false);
-      if (request.showError) toast.error(extractErrorMessage(error));
-      request.onError?.(error);
-    });
-}
-
-export function AxiosDelete<RequestData, ResponseData>({
-  endpoint,
-  request,
-  options
-}: IAxiosRequest<RequestData, ResponseData>) {
-  request.setLoading?.(true);
-  axiosInstance
-    .delete<ResponseData>(endpoint, options)
-    .then(response => {
-      request.setLoading?.(false);
-      request.onSuccess?.(response.data);
-    })
-    .catch((error: Error | AxiosError) => {
-      request.setLoading?.(false);
-      if (request.showError) toast.error(extractErrorMessage(error));
-      request.onError?.(error);
-    });
-}
-
-export function AxiosPatch<RequestData, ResponseData>({
-  endpoint,
-  request,
-  options
-}: IAxiosRequest<RequestData, ResponseData>) {
-  request.setLoading?.(true);
-  axiosInstance
-    .patch<ResponseData>(endpoint, request.data, options)
-    .then(response => {
-      request.setLoading?.(false);
-      request.onSuccess?.(response.data);
+      if (request?.successMessage) {
+        if (typeof request.successMessage === 'string') {
+          toast.success(request.successMessage);
+        } else {
+          toast.success(request.successMessage(response.data));
+        }
+      }
       return response.data;
     })
     .catch((error: Error | AxiosError) => {
-      request.setLoading?.(false);
-      if (request.showError) toast.error(extractErrorMessage(error));
-      request.onError?.(error);
+      toast.error(extractErrorMessage(error));
+      console.error(error);
+      throw error;
+    });
+}
+
+export function axiosDelete<RequestData, ResponseData = void>({
+  endpoint,
+  request,
+  options
+}: IAxiosRequest<RequestData, ResponseData>) {
+  return axiosInstance
+    .delete<ResponseData>(endpoint, options)
+    .then(response => {
+      if (request?.successMessage) {
+        if (typeof request.successMessage === 'string') {
+          toast.success(request.successMessage);
+        } else {
+          toast.success(request.successMessage(response.data));
+        }
+      }
+      return response.data;
+    })
+    .catch((error: Error | AxiosError) => {
+      toast.error(extractErrorMessage(error));
+      console.error(error);
+      throw error;
+    });
+}
+
+export function axiosPatch<RequestData, ResponseData = void>({
+  endpoint,
+  request,
+  options
+}: IAxiosRequest<RequestData, ResponseData>) {
+  return axiosInstance
+    .patch<ResponseData>(endpoint, request?.data, options)
+    .then(response => {
+      if (request?.successMessage) {
+        if (typeof request.successMessage === 'string') {
+          toast.success(request.successMessage);
+        } else {
+          toast.success(request.successMessage(response.data));
+        }
+      }
+      return response.data;
+    })
+    .catch((error: Error | AxiosError) => {
+      toast.error(extractErrorMessage(error));
+      console.error(error);
+      throw error;
     });
 }

rsconcept/frontend/src/backend/auth/api.ts

@@ -1,8 +1,9 @@
 import { queryOptions } from '@tanstack/react-query';
 
-import { ICurrentUser, IUser } from '@/models/user';
-
-import { axiosInstance } from '../apiConfiguration';
+import { axiosGet, axiosPost } from '@/backend/apiTransport';
+import { DELAYS } from '@/backend/configuration';
+import { ICurrentUser } from '@/models/user';
+import { information } from '@/utils/labels';
 
 /**
  * Represents login data, used to authenticate users.
@@ -23,7 +24,9 @@ export interface IChangePasswordDTO {
 /**
  * Represents password reset request data.
  */
-export interface IRequestPasswordDTO extends Pick<IUser, 'email'> {}
+export interface IRequestPasswordDTO {
+  email: string;
+}
 
 /**
  * Represents password reset data.
@@ -36,7 +39,9 @@ export interface IResetPasswordDTO {
 /**
  * Represents password token data.
  */
-export interface IPasswordTokenDTO extends Pick<IResetPasswordDTO, 'token'> {}
+export interface IPasswordTokenDTO {
+  token: string;
+}
 
 /**
  * Authentication API.
@@ -47,21 +52,43 @@ export const authApi = {
   getAuthQueryOptions: () => {
     return queryOptions({
       queryKey: [authApi.baseKey, 'user'],
+      staleTime: DELAYS.staleLong,
       queryFn: meta =>
-        axiosInstance
-          .get<ICurrentUser>('/users/api/auth', {
-            signal: meta.signal
+        axiosGet<ICurrentUser>({
+          endpoint: '/users/api/auth',
+          options: { signal: meta.signal }
         })
-          .then(response => (response.data.id === null ? null : response.data)),
-      placeholderData: null,
-      staleTime: 24 * 60 * 60 * 1000
     });
   },
 
-  logout: () => axiosInstance.post('/users/api/logout'),
-  login: (data: IUserLoginDTO) => axiosInstance.post('/users/api/login', data),
-  changePassword: (data: IChangePasswordDTO) => axiosInstance.post('/users/api/change-password', data),
-  requestPasswordReset: (data: IRequestPasswordDTO) => axiosInstance.post('/users/api/password-reset', data),
-  validatePasswordToken: (data: IPasswordTokenDTO) => axiosInstance.post('/users/api/password-reset/validate', data),
-  resetPassword: (data: IResetPasswordDTO) => axiosInstance.post('/users/api/password-reset/confirm', data)
+  logout: () => axiosPost({ endpoint: '/users/api/logout' }),
+
+  login: (data: IUserLoginDTO) =>
+    axiosPost({
+      endpoint: '/users/api/login',
+      request: { data: data }
+    }),
+  changePassword: (data: IChangePasswordDTO) =>
+    axiosPost({
+      endpoint: '/users/api/change-password',
+      request: {
+        data: data,
+        successMessage: information.changesSaved
+      }
+    }),
+  requestPasswordReset: (data: IRequestPasswordDTO) =>
+    axiosPost({
+      endpoint: '/users/api/password-reset',
+      request: { data: data }
+    }),
+  validatePasswordToken: (data: IPasswordTokenDTO) =>
+    axiosPost({
+      endpoint: '/users/api/password-reset/validate',
+      request: { data: data }
+    }),
+  resetPassword: (data: IResetPasswordDTO) =>
+    axiosPost({
+      endpoint: '/users/api/password-reset/confirm',
+      request: { data: data }
+    })
 };

rsconcept/frontend/src/backend/auth/useAuth.tsx

@@ -1,5 +1,6 @@
 import { useQuery, useSuspenseQuery } from '@tanstack/react-query';
 
+import { queryClient } from '../queryClient';
 import { authApi } from './api';
 
 export function useAuth() {
@@ -10,12 +11,16 @@ export function useAuth() {
   } = useQuery({
     ...authApi.getAuthQueryOptions()
   });
-  return { user, isLoading, error };
+  return { user, isLoading, isAnonymous: user?.id === null || user === undefined, error };
 }
 
 export function useAuthSuspense() {
   const { data: user } = useSuspenseQuery({
     ...authApi.getAuthQueryOptions()
   });
-  return { user };
+  return { user, isAnonymous: user.id === null };
+}
+
+export function prefetchAuth() {
+  return queryClient.prefetchQuery(authApi.getAuthQueryOptions());
 }

rsconcept/frontend/src/backend/auth/useChangePassword.tsx

@@ -3,14 +3,17 @@ import { useMutation, useQueryClient } from '@tanstack/react-query';
 import { authApi, IChangePasswordDTO } from './api';
 
 export const useChangePassword = () => {
-  const queryClient = useQueryClient();
+  const client = useQueryClient();
   const mutation = useMutation({
     mutationKey: ['change-password'],
     mutationFn: authApi.changePassword,
-    onSettled: () => queryClient.invalidateQueries({ queryKey: [authApi.baseKey] })
+    onSettled: () => client.invalidateQueries({ queryKey: [authApi.baseKey] })
   });
   return {
-    changePassword: (data: IChangePasswordDTO, onSuccess?: () => void) => mutation.mutate(data, { onSuccess }),
+    changePassword: (
+      data: IChangePasswordDTO, //
+      onSuccess?: () => void
+    ) => mutation.mutate(data, { onSuccess }),
     isPending: mutation.isPending,
     error: mutation.error,
     reset: mutation.reset

rsconcept/frontend/src/backend/auth/useLogin.tsx

@@ -1,17 +1,23 @@
 import { useMutation, useQueryClient } from '@tanstack/react-query';
 
+import { libraryApi } from '@/backend/library/api';
+
 import { authApi } from './api';
 
 export const useLogin = () => {
-  const queryClient = useQueryClient();
+  const client = useQueryClient();
   const mutation = useMutation({
     mutationKey: ['login'],
     mutationFn: authApi.login,
-    onSettled: () => queryClient.invalidateQueries({ queryKey: [authApi.baseKey] })
+    onSettled: () => client.invalidateQueries({ queryKey: [authApi.baseKey] }),
+    onSuccess: () => client.removeQueries({ queryKey: [libraryApi.baseKey] })
   });
   return {
-    login: (username: string, password: string, onSuccess?: () => void) =>
-      mutation.mutate({ username, password }, { onSuccess }),
+    login: (
+      username: string, //
+      password: string,
+      onSuccess?: () => void
+    ) => mutation.mutate({ username, password }, { onSuccess }),
     isPending: mutation.isPending,
     error: mutation.error,
     reset: mutation.reset

rsconcept/frontend/src/backend/auth/useLogout.tsx

@@ -3,11 +3,12 @@ import { useMutation, useQueryClient } from '@tanstack/react-query';
 import { authApi } from './api';
 
 export const useLogout = () => {
-  const queryClient = useQueryClient();
+  const client = useQueryClient();
   const mutation = useMutation({
     mutationKey: ['logout'],
     mutationFn: authApi.logout,
-    onSettled: () => queryClient.invalidateQueries({ queryKey: [authApi.baseKey] })
+    onSettled: () => client.invalidateQueries({ queryKey: [authApi.baseKey] }),
+    onSuccess: () => client.removeQueries()
   });
   return { logout: (onSuccess?: () => void) => mutation.mutate(undefined, { onSuccess }) };
 };

rsconcept/frontend/src/backend/auth/useRequestPasswordReset.tsx

@@ -8,7 +8,10 @@ export const useRequestPasswordReset = () => {
     mutationFn: authApi.requestPasswordReset
   });
   return {
-    requestPasswordReset: (data: IRequestPasswordDTO, onSuccess?: () => void) => mutation.mutate(data, { onSuccess }),
+    requestPasswordReset: (
+      data: IRequestPasswordDTO, //
+      onSuccess?: () => void
+    ) => mutation.mutate(data, { onSuccess }),
     isPending: mutation.isPending,
     error: mutation.error,
     reset: mutation.reset

rsconcept/frontend/src/backend/auth/useResetPassword.tsx

@@ -1,23 +1,26 @@
-import { useMutation, useQueryClient } from '@tanstack/react-query';
+import { useMutation } from '@tanstack/react-query';
 
 import { authApi, IPasswordTokenDTO, IResetPasswordDTO } from './api';
 
 export const useResetPassword = () => {
-  const queryClient = useQueryClient();
   const validateMutation = useMutation({
     mutationKey: ['reset-password'],
-    mutationFn: authApi.validatePasswordToken,
-    onSuccess: () => queryClient.invalidateQueries({ queryKey: [authApi.baseKey] })
+    mutationFn: authApi.validatePasswordToken
   });
   const resetMutation = useMutation({
     mutationKey: ['reset-password'],
-    mutationFn: authApi.resetPassword,
-    onSuccess: () => queryClient.invalidateQueries({ queryKey: [authApi.baseKey] })
+    mutationFn: authApi.resetPassword
   });
   return {
-    validateToken: (data: IPasswordTokenDTO, onSuccess?: () => void) => validateMutation.mutate(data, { onSuccess }),
-    resetPassword: (data: IResetPasswordDTO, onSuccess?: () => void) => resetMutation.mutate(data, { onSuccess }),
-    isPending: resetMutation.isPending,
+    validateToken: (
+      data: IPasswordTokenDTO, //
+      onSuccess?: () => void
+    ) => validateMutation.mutate(data, { onSuccess }),
+    resetPassword: (
+      data: IResetPasswordDTO, //
+      onSuccess?: () => void
+    ) => resetMutation.mutate(data, { onSuccess }),
+    isPending: resetMutation.isPending || validateMutation.isPending,
     error: resetMutation.error,
     reset: resetMutation.reset
   };

rsconcept/frontend/src/backend/cctext.ts

@@ -1,28 +0,0 @@
-/**
- * Endpoints: cctext.
- */
-
-import { ILexemeData, ITextRequest, ITextResult, IWordFormPlain } from '@/models/language';
-
-import { AxiosPost, FrontExchange } from './apiTransport';
-
-export function postInflectText(request: FrontExchange<IWordFormPlain, ITextResult>) {
-  AxiosPost({
-    endpoint: `/api/cctext/inflect`,
-    request: request
-  });
-}
-
-export function postParseText(request: FrontExchange<ITextRequest, ITextResult>) {
-  AxiosPost({
-    endpoint: `/api/cctext/parse`,
-    request: request
-  });
-}
-
-export function postGenerateLexeme(request: FrontExchange<ITextRequest, ILexemeData>) {
-  AxiosPost({
-    endpoint: `/api/cctext/generate-lexeme`,
-    request: request
-  });
-}

rsconcept/frontend/src/backend/cctext/api.ts

@@ -0,0 +1,29 @@
+import { axiosPost } from '@/backend/apiTransport';
+import { ILexemeData, IWordFormPlain } from '@/models/language';
+
+/**
+ * Represents API result for text output.
+ */
+export interface ITextResult {
+  result: string;
+}
+
+export const cctextApi = {
+  baseKey: 'cctext',
+
+  inflectText: (data: IWordFormPlain) =>
+    axiosPost<IWordFormPlain, ITextResult>({
+      endpoint: '/api/cctext/inflect',
+      request: { data: data }
+    }),
+  parseText: (data: { text: string }) =>
+    axiosPost<{ text: string }, ITextResult>({
+      endpoint: '/api/cctext/parse',
+      request: { data: data }
+    }),
+  generateLexeme: (data: { text: string }) =>
+    axiosPost<{ text: string }, ILexemeData>({
+      endpoint: '/api/cctext/generate-lexeme',
+      request: { data: data }
+    })
+};

rsconcept/frontend/src/backend/cctext/useGenerateLexeme.tsx

@@ -0,0 +1,19 @@
+import { useMutation } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { ILexemeData } from '@/models/language';
+
+import { cctextApi } from './api';
+
+export const useGenerateLexeme = () => {
+  const mutation = useMutation({
+    mutationKey: [cctextApi.baseKey, 'generate-lexeme'],
+    mutationFn: cctextApi.generateLexeme
+  });
+  return {
+    generateLexeme: (
+      data: { text: string }, //
+      onSuccess?: DataCallback<ILexemeData>
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/cctext/useInflectText.tsx

@@ -0,0 +1,19 @@
+import { useMutation } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { IWordFormPlain } from '@/models/language';
+
+import { cctextApi, ITextResult } from './api';
+
+export const useInflectText = () => {
+  const mutation = useMutation({
+    mutationKey: [cctextApi.baseKey, 'inflect-text'],
+    mutationFn: cctextApi.inflectText
+  });
+  return {
+    inflectText: (
+      data: IWordFormPlain, //
+      onSuccess?: DataCallback<ITextResult>
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/cctext/useIsProcessingCctext.tsx

@@ -0,0 +1,8 @@
+import { useIsMutating } from '@tanstack/react-query';
+
+import { cctextApi } from './api';
+
+export const useIsProcessingCctext = () => {
+  const countMutations = useIsMutating({ mutationKey: [cctextApi.baseKey] });
+  return countMutations !== 0;
+};

rsconcept/frontend/src/backend/cctext/useParseText.tsx

@@ -0,0 +1,18 @@
+import { useMutation } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+
+import { cctextApi, ITextResult } from './api';
+
+export const useParseText = () => {
+  const mutation = useMutation({
+    mutationKey: [cctextApi.baseKey, 'parse-text'],
+    mutationFn: cctextApi.parseText
+  });
+  return {
+    parseText: (
+      data: { text: string }, //
+      onSuccess?: DataCallback<ITextResult>
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/configuration.ts

@@ -0,0 +1,9 @@
+/** Timing constants for API requests. */
+export const DELAYS = {
+  garbageCollection: 1 * 60 * 60 * 1000,
+  staleDefault: 5 * 60 * 1000,
+
+  staleShort: 5 * 60 * 1000,
+  staleMedium: 1 * 60 * 60 * 1000,
+  staleLong: 24 * 60 * 60 * 1000
+};

rsconcept/frontend/src/backend/library.ts

@@ -1,117 +0,0 @@
-/**
- * Endpoints: library.
- */
-
-import {
-  ILibraryCreateData,
-  ILibraryItem,
-  ILibraryUpdateData,
-  IRenameLocationData,
-  ITargetAccessPolicy,
-  ITargetLocation,
-  IVersionCreateData
-} from '@/models/library';
-import { IRSFormCloneData, IRSFormData, IVersionCreatedResponse } from '@/models/rsform';
-import { ITargetUser, ITargetUsers } from '@/models/user';
-
-import {
-  AxiosDelete,
-  AxiosGet,
-  AxiosPatch,
-  AxiosPost,
-  FrontAction,
-  FrontExchange,
-  FrontPull,
-  FrontPush
-} from './apiTransport';
-
-export function getLibrary(request: FrontPull<ILibraryItem[]>) {
-  AxiosGet({
-    endpoint: '/api/library/active',
-    request: request
-  });
-}
-
-export function getAdminLibrary(request: FrontPull<ILibraryItem[]>) {
-  AxiosGet({
-    endpoint: '/api/library/all',
-    request: request
-  });
-}
-
-export function getTemplates(request: FrontPull<ILibraryItem[]>) {
-  AxiosGet({
-    endpoint: '/api/library/templates',
-    request: request
-  });
-}
-
-export function postCreateLibraryItem(request: FrontExchange<ILibraryCreateData, ILibraryItem>) {
-  AxiosPost({
-    endpoint: '/api/library',
-    request: request
-  });
-}
-
-export function postCloneLibraryItem(target: string, request: FrontExchange<IRSFormCloneData, IRSFormData>) {
-  AxiosPost({
-    endpoint: `/api/library/${target}/clone`,
-    request: request
-  });
-}
-
-export function patchLibraryItem(target: string, request: FrontExchange<ILibraryUpdateData, ILibraryItem>) {
-  AxiosPatch({
-    endpoint: `/api/library/${target}`,
-    request: request
-  });
-}
-
-export function deleteLibraryItem(target: string, request: FrontAction) {
-  AxiosDelete({
-    endpoint: `/api/library/${target}`,
-    request: request
-  });
-}
-
-export function patchSetOwner(target: string, request: FrontPush<ITargetUser>) {
-  AxiosPatch({
-    endpoint: `/api/library/${target}/set-owner`,
-    request: request
-  });
-}
-
-export function patchSetAccessPolicy(target: string, request: FrontPush<ITargetAccessPolicy>) {
-  AxiosPatch({
-    endpoint: `/api/library/${target}/set-access-policy`,
-    request: request
-  });
-}
-
-export function patchSetLocation(target: string, request: FrontPush<ITargetLocation>) {
-  AxiosPatch({
-    endpoint: `/api/library/${target}/set-location`,
-    request: request
-  });
-}
-
-export function patchRenameLocation(request: FrontPush<IRenameLocationData>) {
-  AxiosPatch({
-    endpoint: `/api/library/rename-location`,
-    request: request
-  });
-}
-
-export function patchSetEditors(target: string, request: FrontPush<ITargetUsers>) {
-  AxiosPatch({
-    endpoint: `/api/library/${target}/set-editors`,
-    request: request
-  });
-}
-
-export function postCreateVersion(target: string, request: FrontExchange<IVersionCreateData, IVersionCreatedResponse>) {
-  AxiosPost({
-    endpoint: `/api/library/${target}/create-version`,
-    request: request
-  });
-}

rsconcept/frontend/src/backend/library/api.ts

@@ -0,0 +1,206 @@
+import { queryOptions } from '@tanstack/react-query';
+
+import { axiosDelete, axiosGet, axiosPatch, axiosPost } from '@/backend/apiTransport';
+import { DELAYS } from '@/backend/configuration';
+import { ossApi } from '@/backend/oss/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import {
+  AccessPolicy,
+  ILibraryItem,
+  IVersionData,
+  IVersionInfo,
+  LibraryItemID,
+  LibraryItemType,
+  VersionID
+} from '@/models/library';
+import { ConstituentaID, IRSFormData } from '@/models/rsform';
+import { UserID } from '@/models/user';
+import { information } from '@/utils/labels';
+
+/**
+ * Represents update data for renaming Location.
+ */
+export interface IRenameLocationDTO {
+  target: string;
+  new_location: string;
+}
+
+/**
+ * Represents data, used for cloning {@link IRSForm}.
+ */
+export interface IRSFormCloneDTO extends Omit<ILibraryItem, 'time_create' | 'time_update' | 'owner'> {
+  items?: ConstituentaID[];
+}
+
+/**
+ * Represents data, used for creating {@link IRSForm}.
+ */
+export interface ILibraryCreateDTO extends Omit<ILibraryItem, 'time_create' | 'time_update' | 'id' | 'owner'> {
+  file?: File;
+  fileName?: string;
+}
+
+/**
+ * Represents update data for editing {@link ILibraryItem}.
+ */
+export interface ILibraryUpdateDTO
+  extends Omit<ILibraryItem, 'time_create' | 'time_update' | 'access_policy' | 'location' | 'owner'> {}
+
+/**
+ * Create version metadata in persistent storage.
+ */
+export interface IVersionCreateDTO {
+  version: string;
+  description: string;
+  items?: ConstituentaID[];
+}
+
+/**
+ * Represents data response when creating {@link IVersionInfo}.
+ */
+export interface IVersionCreatedResponse {
+  version: number;
+  schema: IRSFormData;
+}
+
+export const libraryApi = {
+  baseKey: 'library',
+  libraryListKey: ['library', 'list'],
+
+  getItemQueryOptions: ({ itemID, itemType }: { itemID: LibraryItemID; itemType: LibraryItemType }) => {
+    return itemType === LibraryItemType.RSFORM
+      ? rsformsApi.getRSFormQueryOptions({ itemID })
+      : ossApi.getOssQueryOptions({ itemID });
+  },
+  getLibraryQueryOptions: ({ isAdmin }: { isAdmin: boolean }) =>
+    queryOptions({
+      queryKey: [...libraryApi.libraryListKey, isAdmin ? 'admin' : 'user'],
+      staleTime: DELAYS.staleMedium,
+      queryFn: meta =>
+        axiosGet<ILibraryItem[]>({
+          endpoint: isAdmin ? '/api/library/all' : '/api/library/active',
+          options: { signal: meta.signal }
+        })
+    }),
+  getTemplatesQueryOptions: () =>
+    queryOptions({
+      queryKey: [libraryApi.baseKey, 'templates'],
+      staleTime: DELAYS.staleMedium,
+      queryFn: meta =>
+        axiosGet<ILibraryItem[]>({
+          endpoint: '/api/library/templates',
+          options: { signal: meta.signal }
+        })
+    }),
+
+  createItem: (data: ILibraryCreateDTO) =>
+    axiosPost<ILibraryCreateDTO, ILibraryItem>({
+      endpoint: !data.file ? '/api/library' : '/api/rsforms/create-detailed',
+      request: {
+        data: data,
+        successMessage: information.newLibraryItem
+      },
+      options: !data.file
+        ? undefined
+        : {
+            headers: {
+              'Content-Type': 'multipart/form-data'
+            }
+          }
+    }),
+  updateItem: (data: ILibraryUpdateDTO) =>
+    axiosPatch<ILibraryUpdateDTO, ILibraryItem>({
+      endpoint: `/api/library/${data.id}`,
+      request: {
+        data: data,
+        successMessage: information.changesSaved
+      }
+    }),
+  setOwner: ({ itemID, owner }: { itemID: LibraryItemID; owner: UserID }) =>
+    axiosPatch({
+      endpoint: `/api/library/${itemID}/set-owner`,
+      request: {
+        data: { user: owner },
+        successMessage: information.changesSaved
+      }
+    }),
+  setLocation: ({ itemID, location }: { itemID: LibraryItemID; location: string }) =>
+    axiosPatch({
+      endpoint: `/api/library/${itemID}/set-location`,
+      request: {
+        data: { location: location },
+        successMessage: information.moveComplete
+      }
+    }),
+  setAccessPolicy: ({ itemID, policy }: { itemID: LibraryItemID; policy: AccessPolicy }) =>
+    axiosPatch({
+      endpoint: `/api/library/${itemID}/set-access-policy`,
+      request: {
+        data: { access_policy: policy },
+        successMessage: information.changesSaved
+      }
+    }),
+  setEditors: ({ itemID, editors }: { itemID: LibraryItemID; editors: UserID[] }) =>
+    axiosPatch({
+      endpoint: `/api/library/${itemID}/set-editors`,
+      request: {
+        data: { users: editors },
+        successMessage: information.changesSaved
+      }
+    }),
+
+  deleteItem: (target: LibraryItemID) =>
+    axiosDelete({
+      endpoint: `/api/library/${target}`,
+      request: {
+        successMessage: information.itemDestroyed
+      }
+    }),
+  cloneItem: (data: IRSFormCloneDTO) =>
+    axiosPost<IRSFormCloneDTO, IRSFormData>({
+      endpoint: `/api/library/${data.id}/clone`,
+      request: {
+        data: data,
+        successMessage: newSchema => information.cloneComplete(newSchema.alias)
+      }
+    }),
+  renameLocation: (data: IRenameLocationDTO) =>
+    axiosPatch({
+      endpoint: '/api/library/rename-location',
+      request: {
+        data: data,
+        successMessage: information.locationRenamed
+      }
+    }),
+
+  versionCreate: ({ itemID, data }: { itemID: LibraryItemID; data: IVersionData }) =>
+    axiosPost<IVersionData, IVersionCreatedResponse>({
+      endpoint: `/api/library/${itemID}/create-version`,
+      request: {
+        data: data,
+        successMessage: information.newVersion(data.version)
+      }
+    }),
+  versionRestore: ({ versionID }: { versionID: VersionID }) =>
+    axiosPatch<undefined, IRSFormData>({
+      endpoint: `/api/versions/${versionID}/restore`,
+      request: {
+        successMessage: information.versionRestored
+      }
+    }),
+  versionUpdate: ({ versionID, data }: { versionID: VersionID; data: IVersionData }) =>
+    axiosPatch<IVersionData, IVersionInfo>({
+      endpoint: `/api/versions/${versionID}`,
+      request: {
+        data: data,
+        successMessage: information.changesSaved
+      }
+    }),
+  versionDelete: (data: { itemID: LibraryItemID; versionID: VersionID }) =>
+    axiosDelete({
+      endpoint: `/api/versions/${data.versionID}`,
+      request: {
+        successMessage: information.versionDestroyed
+      }
+    })
+};

rsconcept/frontend/src/backend/library/useApplyLibraryFilter.tsx

@@ -0,0 +1,47 @@
+import { useAuthSuspense } from '@/backend/auth/useAuth';
+import { matchLibraryItem, matchLibraryItemLocation } from '@/models/libraryAPI';
+import { ILibraryFilter } from '@/models/miscellaneous';
+
+import { useLibrary } from './useLibrary';
+
+export function useApplyLibraryFilter(filter: ILibraryFilter) {
+  const { items } = useLibrary();
+  const { user } = useAuthSuspense();
+
+  let result = items;
+  if (!filter.folderMode && filter.head) {
+    result = result.filter(item => item.location.startsWith(filter.head!));
+  }
+  if (filter.folderMode && filter.location) {
+    if (filter.subfolders) {
+      result = result.filter(
+        item => item.location == filter.location || item.location.startsWith(filter.location! + '/')
+      );
+    } else {
+      result = result.filter(item => item.location == filter.location);
+    }
+  }
+  if (filter.type) {
+    result = result.filter(item => item.item_type === filter.type);
+  }
+  if (filter.isVisible !== undefined) {
+    result = result.filter(item => filter.isVisible === item.visible);
+  }
+  if (filter.isOwned !== undefined) {
+    result = result.filter(item => filter.isOwned === (item.owner === user.id));
+  }
+  if (filter.isEditor !== undefined) {
+    result = result.filter(item => filter.isEditor == user.editor.includes(item.id));
+  }
+  if (filter.filterUser !== undefined) {
+    result = result.filter(item => filter.filterUser === item.owner);
+  }
+  if (!filter.folderMode && filter.path) {
+    result = result.filter(item => matchLibraryItemLocation(item, filter.path!));
+  }
+  if (filter.query) {
+    result = result.filter(item => matchLibraryItem(item, filter.query!));
+  }
+
+  return { filtered: result };
+}

rsconcept/frontend/src/backend/library/useCloneItem.tsx

@@ -0,0 +1,21 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { IRSFormData } from '@/models/rsform';
+
+import { IRSFormCloneDTO, libraryApi } from './api';
+
+export const useCloneItem = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'clone-item'],
+    mutationFn: libraryApi.cloneItem,
+    onSuccess: () => client.invalidateQueries({ queryKey: [libraryApi.baseKey] })
+  });
+  return {
+    cloneItem: (
+      data: IRSFormCloneDTO, //
+      onSuccess?: DataCallback<IRSFormData>
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/library/useCreateItem.tsx

@@ -0,0 +1,24 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { ILibraryItem } from '@/models/library';
+
+import { ILibraryCreateDTO, libraryApi } from './api';
+
+export const useCreateItem = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'create-item'],
+    mutationFn: libraryApi.createItem,
+    onSuccess: () => client.invalidateQueries({ queryKey: [libraryApi.baseKey] })
+  });
+  return {
+    createItem: (
+      data: ILibraryCreateDTO, //
+      onSuccess?: DataCallback<ILibraryItem>
+    ) => mutation.mutate(data, { onSuccess }),
+    isPending: mutation.isPending,
+    error: mutation.error,
+    reset: mutation.reset
+  };
+};

rsconcept/frontend/src/backend/library/useDeleteItem.tsx

@@ -0,0 +1,31 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { ossApi } from '@/backend/oss/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { ILibraryItem, LibraryItemID } from '@/models/library';
+
+import { libraryApi } from './api';
+
+export const useDeleteItem = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'delete-item'],
+    mutationFn: libraryApi.deleteItem,
+    onSuccess: (_, variables) => {
+      client.setQueryData(libraryApi.libraryListKey, (prev: ILibraryItem[] | undefined) =>
+        prev?.filter(item => item.id !== variables)
+      );
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({ queryKey: rsformsApi.getRSFormQueryOptions({ itemID: variables }).queryKey })
+      ]);
+    }
+  });
+  return {
+    deleteItem: (
+      target: LibraryItemID, //
+      onSuccess?: () => void
+    ) => mutation.mutate(target, { onSuccess }),
+    isPending: mutation.isPending
+  };
+};

rsconcept/frontend/src/backend/library/useFolders.tsx

@@ -0,0 +1,17 @@
+import { FolderTree } from '@/models/FolderTree';
+import { LocationHead } from '@/models/library';
+
+import { useLibrary } from './useLibrary';
+
+export function useFolders() {
+  const { items } = useLibrary();
+
+  const result = new FolderTree();
+  result.addPath(LocationHead.USER, 0);
+  result.addPath(LocationHead.COMMON, 0);
+  result.addPath(LocationHead.LIBRARY, 0);
+  result.addPath(LocationHead.PROJECTS, 0);
+  items.forEach(item => result.addPath(item.location));
+
+  return { folders: result };
+}

rsconcept/frontend/src/backend/library/useLibrary.tsx

@@ -0,0 +1,29 @@
+import { useQuery, useSuspenseQuery } from '@tanstack/react-query';
+
+import { useAuthSuspense } from '@/backend/auth/useAuth';
+import { queryClient } from '@/backend/queryClient';
+import { usePreferencesStore } from '@/stores/preferences';
+
+import { libraryApi } from './api';
+
+export function useLibrarySuspense() {
+  const adminMode = usePreferencesStore(state => state.adminMode);
+  const { user } = useAuthSuspense();
+  const { data: items } = useSuspenseQuery({
+    ...libraryApi.getLibraryQueryOptions({ isAdmin: user.is_staff && adminMode })
+  });
+  return { items };
+}
+
+export function useLibrary() {
+  const adminMode = usePreferencesStore(state => state.adminMode);
+  const { user } = useAuthSuspense();
+  const { data: items, isLoading } = useQuery({
+    ...libraryApi.getLibraryQueryOptions({ isAdmin: user.is_staff && adminMode })
+  });
+  return { items: items ?? [], isLoading };
+}
+
+export function prefetchLibrary() {
+  return queryClient.prefetchQuery(libraryApi.getLibraryQueryOptions({ isAdmin: false }));
+}

rsconcept/frontend/src/backend/library/useMutatingLibrary.tsx

@@ -0,0 +1,13 @@
+import { useIsMutating } from '@tanstack/react-query';
+
+import { ossApi } from '@/backend/oss/api';
+import { rsformsApi } from '@/backend/rsform/api';
+
+import { libraryApi } from './api';
+
+export const useMutatingLibrary = () => {
+  const countMutations = useIsMutating({ mutationKey: [libraryApi.baseKey] });
+  const countOss = useIsMutating({ mutationKey: [ossApi.baseKey] });
+  const countRSForm = useIsMutating({ mutationKey: [rsformsApi.baseKey] });
+  return countMutations + countOss + countRSForm !== 0;
+};

rsconcept/frontend/src/backend/library/useRenameLocation.tsx

@@ -0,0 +1,26 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { ossApi } from '@/backend/oss/api';
+import { rsformsApi } from '@/backend/rsform/api';
+
+import { IRenameLocationDTO, libraryApi } from './api';
+
+export const useRenameLocation = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'rename-location'],
+    mutationFn: libraryApi.renameLocation,
+    onSuccess: () =>
+      Promise.allSettled([
+        client.invalidateQueries({ queryKey: [libraryApi.baseKey] }),
+        client.invalidateQueries({ queryKey: [rsformsApi.baseKey] }),
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] })
+      ])
+  });
+  return {
+    renameLocation: (
+      data: IRenameLocationDTO, //
+      onSuccess?: () => void
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/library/useSetAccessPolicy.tsx

@@ -0,0 +1,45 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { ossApi } from '@/backend/oss/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { AccessPolicy, ILibraryItem, LibraryItemID } from '@/models/library';
+import { IOperationSchemaData } from '@/models/oss';
+
+import { libraryApi } from './api';
+
+export const useSetAccessPolicy = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'set-location'],
+    mutationFn: libraryApi.setAccessPolicy,
+    onSuccess: (_, variables) => {
+      const ossKey = ossApi.getOssQueryOptions({ itemID: variables.itemID }).queryKey;
+      const ossData: IOperationSchemaData | undefined = client.getQueryData(ossKey);
+      if (ossData) {
+        client.setQueryData(ossKey, { ...ossData, access_policy: variables.policy });
+        return Promise.allSettled([
+          client.invalidateQueries({ queryKey: libraryApi.libraryListKey }),
+          ...ossData.items
+            .map(item => {
+              if (!item.result) {
+                return;
+              }
+              const itemKey = rsformsApi.getRSFormQueryOptions({ itemID: item.result }).queryKey;
+              return client.invalidateQueries({ queryKey: itemKey });
+            })
+            .filter(item => !!item)
+        ]);
+      }
+
+      const rsKey = rsformsApi.getRSFormQueryOptions({ itemID: variables.itemID }).queryKey;
+      client.setQueryData(rsKey, prev => (!prev ? undefined : { ...prev, access_policy: variables.policy }));
+      client.setQueryData(libraryApi.libraryListKey, (prev: ILibraryItem[] | undefined) =>
+        prev?.map(item => (item.id === variables.itemID ? { ...item, access_policy: variables.policy } : item))
+      );
+    }
+  });
+
+  return {
+    setAccessPolicy: (data: { itemID: LibraryItemID; policy: AccessPolicy }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/library/useSetEditors.tsx

@@ -0,0 +1,41 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { ossApi } from '@/backend/oss/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { LibraryItemID } from '@/models/library';
+import { UserID } from '@/models/user';
+
+import { libraryApi } from './api';
+
+export const useSetEditors = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'set-location'],
+    mutationFn: libraryApi.setEditors,
+    onSuccess: (_, variables) => {
+      const ossKey = ossApi.getOssQueryOptions({ itemID: variables.itemID }).queryKey;
+      const ossData = client.getQueryData(ossKey);
+      if (ossData) {
+        client.setQueryData(ossKey, { ...ossData, editors: variables.editors });
+        return Promise.allSettled(
+          ossData.items
+            .map(item => {
+              if (!item.result) {
+                return;
+              }
+              const itemKey = rsformsApi.getRSFormQueryOptions({ itemID: item.result }).queryKey;
+              return client.invalidateQueries({ queryKey: itemKey });
+            })
+            .filter(item => !!item)
+        );
+      }
+
+      const rsKey = rsformsApi.getRSFormQueryOptions({ itemID: variables.itemID }).queryKey;
+      client.setQueryData(rsKey, prev => (!prev ? undefined : { ...prev, editors: variables.editors }));
+    }
+  });
+
+  return {
+    setEditors: (data: { itemID: LibraryItemID; editors: UserID[] }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/library/useSetLocation.tsx

@@ -0,0 +1,51 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { ossApi } from '@/backend/oss/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { ILibraryItem, LibraryItemID } from '@/models/library';
+import { IOperationSchemaData } from '@/models/oss';
+
+import { libraryApi } from './api';
+
+export const useSetLocation = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'set-location'],
+    mutationFn: libraryApi.setLocation,
+    onSuccess: (_, variables) => {
+      const ossKey = ossApi.getOssQueryOptions({ itemID: variables.itemID }).queryKey;
+      const ossData: IOperationSchemaData | undefined = client.getQueryData(ossKey);
+      if (ossData) {
+        client.setQueryData(ossKey, { ...ossData, location: variables.location });
+        return Promise.allSettled([
+          client.invalidateQueries({ queryKey: libraryApi.libraryListKey }),
+          ...ossData.items
+            .map(item => {
+              if (!item.result) {
+                return;
+              }
+              const itemKey = rsformsApi.getRSFormQueryOptions({ itemID: item.result }).queryKey;
+              return client.invalidateQueries({ queryKey: itemKey });
+            })
+            .filter(item => !!item)
+        ]);
+      }
+
+      const rsKey = rsformsApi.getRSFormQueryOptions({ itemID: variables.itemID }).queryKey;
+      client.setQueryData(rsKey, prev => (!prev ? undefined : { ...prev, location: variables.location }));
+      client.setQueryData(libraryApi.libraryListKey, (prev: ILibraryItem[] | undefined) =>
+        prev?.map(item => (item.id === variables.itemID ? { ...item, location: variables.location } : item))
+      );
+    }
+  });
+
+  return {
+    setLocation: (
+      data: {
+        itemID: LibraryItemID; //
+        location: string;
+      },
+      onSuccess?: () => void
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/library/useSetOwner.tsx

@@ -0,0 +1,46 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { ossApi } from '@/backend/oss/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { ILibraryItem, LibraryItemID } from '@/models/library';
+import { IOperationSchemaData } from '@/models/oss';
+import { UserID } from '@/models/user';
+
+import { libraryApi } from './api';
+
+export const useSetOwner = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'set-owner'],
+    mutationFn: libraryApi.setOwner,
+    onSuccess: (_, variables) => {
+      const ossKey = ossApi.getOssQueryOptions({ itemID: variables.itemID }).queryKey;
+      const ossData: IOperationSchemaData | undefined = client.getQueryData(ossKey);
+      if (ossData) {
+        client.setQueryData(ossKey, { ...ossData, owner: variables.owner });
+        return Promise.allSettled([
+          client.invalidateQueries({ queryKey: libraryApi.libraryListKey }),
+          ...ossData.items
+            .map(item => {
+              if (!item.result) {
+                return;
+              }
+              const itemKey = rsformsApi.getRSFormQueryOptions({ itemID: item.result }).queryKey;
+              return client.invalidateQueries({ queryKey: itemKey });
+            })
+            .filter(item => !!item)
+        ]);
+      }
+
+      const rsKey = rsformsApi.getRSFormQueryOptions({ itemID: variables.itemID }).queryKey;
+      client.setQueryData(rsKey, prev => (!prev ? undefined : { ...prev, owner: variables.owner }));
+      client.setQueryData(libraryApi.libraryListKey, (prev: ILibraryItem[] | undefined) =>
+        prev?.map(item => (item.id === variables.itemID ? { ...item, owner: variables.owner } : item))
+      );
+    }
+  });
+
+  return {
+    setOwner: (data: { itemID: LibraryItemID; owner: UserID }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/library/useTemplates.tsx

@@ -0,0 +1,23 @@
+import { useQuery, useSuspenseQuery } from '@tanstack/react-query';
+
+import { queryClient } from '@/backend/queryClient';
+
+import { libraryApi } from './api';
+
+export function useTemplatesSuspense() {
+  const { data: templates } = useSuspenseQuery({
+    ...libraryApi.getTemplatesQueryOptions()
+  });
+  return { templates };
+}
+
+export function useTemplates() {
+  const { data: templates } = useQuery({
+    ...libraryApi.getTemplatesQueryOptions()
+  });
+  return { templates: templates ?? [] };
+}
+
+export function prefetchTemplates() {
+  return queryClient.prefetchQuery(libraryApi.getTemplatesQueryOptions());
+}

rsconcept/frontend/src/backend/library/useUpdateItem.tsx

@@ -0,0 +1,38 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { ossApi } from '@/backend/oss/api';
+import { ILibraryItem, LibraryItemType } from '@/models/library';
+import { IOperationSchemaData } from '@/models/oss';
+import { IRSFormData } from '@/models/rsform';
+
+import { ILibraryUpdateDTO, libraryApi } from './api';
+
+export const useUpdateItem = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'update-item'],
+    mutationFn: libraryApi.updateItem,
+    onSuccess: (data: ILibraryItem) => {
+      const itemKey = libraryApi.getItemQueryOptions({ itemID: data.id, itemType: data.item_type }).queryKey;
+      client.setQueryData(libraryApi.libraryListKey, (prev: ILibraryItem[] | undefined) =>
+        prev?.map(item => (item.id === data.id ? data : item))
+      );
+      client.setQueryData(itemKey, (prev: IRSFormData | IOperationSchemaData | undefined) =>
+        !prev ? undefined : { ...prev, ...data }
+      );
+      if (data.item_type === LibraryItemType.RSFORM) {
+        const schema: IRSFormData | undefined = client.getQueryData(itemKey);
+        if (schema) {
+          return Promise.allSettled(
+            schema.oss.map(item =>
+              client.invalidateQueries({ queryKey: ossApi.getOssQueryOptions({ itemID: item.id }).queryKey })
+            )
+          );
+        }
+      }
+    }
+  });
+  return {
+    updateItem: (data: ILibraryUpdateDTO) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/library/useUpdateTimestamp.tsx

@@ -0,0 +1,17 @@
+import { useQueryClient } from '@tanstack/react-query';
+
+import { ILibraryItem, LibraryItemID } from '@/models/library';
+
+import { libraryApi } from './api';
+
+export function useUpdateTimestamp() {
+  const client = useQueryClient();
+  return {
+    updateTimestamp: (target: LibraryItemID) =>
+      client.setQueryData(
+        libraryApi.libraryListKey, //
+        (prev: ILibraryItem[] | undefined) =>
+          prev?.map(item => (item.id === target ? { ...item, time_update: Date() } : item))
+      )
+  };
+}

rsconcept/frontend/src/backend/library/useVersionCreate.tsx

@@ -0,0 +1,30 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { rsformsApi } from '@/backend/rsform/api';
+import { IVersionData, LibraryItemID, VersionID } from '@/models/library';
+
+import { libraryApi } from './api';
+
+export const useVersionCreate = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'create-version'],
+    mutationFn: libraryApi.versionCreate,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.schema.id }).queryKey, data.schema);
+      updateTimestamp(data.schema.id);
+    }
+  });
+  return {
+    versionCreate: (
+      data: {
+        itemID: LibraryItemID; //
+        data: IVersionData;
+      },
+      onSuccess?: DataCallback<VersionID>
+    ) => mutation.mutate(data, { onSuccess: response => onSuccess?.(response.version) })
+  };
+};

rsconcept/frontend/src/backend/library/useVersionDelete.tsx

@@ -0,0 +1,36 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { rsformsApi } from '@/backend/rsform/api';
+import { LibraryItemID, VersionID } from '@/models/library';
+import { IRSFormData } from '@/models/rsform';
+
+import { libraryApi } from './api';
+
+export const useVersionDelete = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'delete-version'],
+    mutationFn: libraryApi.versionDelete,
+    onSuccess: (_, variables) => {
+      client.setQueryData(
+        rsformsApi.getRSFormQueryOptions({ itemID: variables.itemID }).queryKey,
+        (prev: IRSFormData | undefined) =>
+          !prev
+            ? undefined
+            : {
+                ...prev,
+                versions: prev.versions.filter(version => version.id !== variables.versionID)
+              }
+      );
+    }
+  });
+  return {
+    versionDelete: (
+      data: {
+        itemID: LibraryItemID; //
+        versionID: VersionID;
+      },
+      onSuccess?: () => void
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/library/useVersionRestore.tsx

@@ -0,0 +1,21 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { rsformsApi } from '@/backend/rsform/api';
+import { VersionID } from '@/models/library';
+
+import { libraryApi } from './api';
+
+export const useVersionRestore = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'restore-version'],
+    mutationFn: libraryApi.versionRestore,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.id }).queryKey, data);
+      return client.invalidateQueries({ queryKey: [libraryApi.baseKey] });
+    }
+  });
+  return {
+    versionRestore: (data: { versionID: VersionID }, onSuccess?: () => void) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/library/useVersionUpdate.tsx

@@ -0,0 +1,34 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { rsformsApi } from '@/backend/rsform/api';
+import { IVersionData, VersionID } from '@/models/library';
+import { IRSFormData } from '@/models/rsform';
+
+import { libraryApi } from './api';
+
+export const useVersionUpdate = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [libraryApi.baseKey, 'update-version'],
+    mutationFn: libraryApi.versionUpdate,
+    onSuccess: data => {
+      client.setQueryData(
+        rsformsApi.getRSFormQueryOptions({ itemID: data.item }).queryKey,
+        (prev: IRSFormData | undefined) =>
+          !prev
+            ? undefined
+            : {
+                ...prev,
+                versions: prev.versions.map(version =>
+                  version.id === data.id
+                    ? { ...version, description: data.description, version: data.version }
+                    : version
+                )
+              }
+      );
+    }
+  });
+  return {
+    versionUpdate: (data: { versionID: VersionID; data: IVersionData }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/oss.ts

@@ -1,92 +0,0 @@
-/**
- * Endpoints: oss.
- */
-
-import {
-  ICstRelocateData,
-  IInputCreatedResponse,
-  IOperationCreateData,
-  IOperationCreatedResponse,
-  IOperationDeleteData,
-  IOperationSchemaData,
-  IOperationSetInputData,
-  IOperationUpdateData,
-  IPositionsData,
-  ITargetOperation
-} from '@/models/oss';
-import { IConstituentaReference, ITargetCst } from '@/models/rsform';
-
-import { AxiosGet, AxiosPatch, AxiosPost, FrontExchange, FrontPull, FrontPush } from './apiTransport';
-
-export function getOssDetails(target: string, request: FrontPull<IOperationSchemaData>) {
-  AxiosGet({
-    endpoint: `/api/oss/${target}/details`,
-    request: request
-  });
-}
-
-export function patchUpdatePositions(oss: string, request: FrontPush<IPositionsData>) {
-  AxiosPatch({
-    endpoint: `/api/oss/${oss}/update-positions`,
-    request: request
-  });
-}
-
-export function postCreateOperation(
-  oss: string,
-  request: FrontExchange<IOperationCreateData, IOperationCreatedResponse>
-) {
-  AxiosPost({
-    endpoint: `/api/oss/${oss}/create-operation`,
-    request: request
-  });
-}
-
-export function patchDeleteOperation(oss: string, request: FrontExchange<IOperationDeleteData, IOperationSchemaData>) {
-  AxiosPatch({
-    endpoint: `/api/oss/${oss}/delete-operation`,
-    request: request
-  });
-}
-
-export function patchCreateInput(oss: string, request: FrontExchange<ITargetOperation, IInputCreatedResponse>) {
-  AxiosPatch({
-    endpoint: `/api/oss/${oss}/create-input`,
-    request: request
-  });
-}
-
-export function patchSetInput(oss: string, request: FrontExchange<IOperationSetInputData, IOperationSchemaData>) {
-  AxiosPatch({
-    endpoint: `/api/oss/${oss}/set-input`,
-    request: request
-  });
-}
-
-export function patchUpdateOperation(oss: string, request: FrontExchange<IOperationUpdateData, IOperationSchemaData>) {
-  AxiosPatch({
-    endpoint: `/api/oss/${oss}/update-operation`,
-    request: request
-  });
-}
-
-export function postExecuteOperation(oss: string, request: FrontExchange<ITargetOperation, IOperationSchemaData>) {
-  AxiosPost({
-    endpoint: `/api/oss/${oss}/execute-operation`,
-    request: request
-  });
-}
-
-export function postRelocateConstituents(request: FrontPush<ICstRelocateData>) {
-  AxiosPost({
-    endpoint: `/api/oss/relocate-constituents`,
-    request: request
-  });
-}
-
-export function postFindPredecessor(request: FrontExchange<ITargetCst, IConstituentaReference>) {
-  AxiosPost({
-    endpoint: `/api/oss/get-predecessor`,
-    request: request
-  });
-}

rsconcept/frontend/src/backend/oss/api.ts

@@ -0,0 +1,191 @@
+import { queryOptions } from '@tanstack/react-query';
+
+import { axiosDelete, axiosGet, axiosPatch, axiosPost } from '@/backend/apiTransport';
+import { DELAYS } from '@/backend/configuration';
+import { ILibraryItem, LibraryItemID } from '@/models/library';
+import {
+  ICstSubstitute,
+  IOperationData,
+  IOperationPosition,
+  IOperationSchemaData,
+  OperationID,
+  OperationType
+} from '@/models/oss';
+import { ConstituentaID, IConstituentaReference, ITargetCst } from '@/models/rsform';
+import { information } from '@/utils/labels';
+
+/**
+ * Represents {@link IOperation} data, used in creation process.
+ */
+export interface IOperationCreateDTO {
+  positions: IOperationPosition[];
+  item_data: {
+    alias: string;
+    operation_type: OperationType;
+    title: string;
+    comment: string;
+    position_x: number;
+    position_y: number;
+    result: LibraryItemID | null;
+  };
+  arguments: OperationID[] | undefined;
+  create_schema: boolean;
+}
+
+/**
+ * Represents data response when creating {@link IOperation}.
+ */
+export interface IOperationCreatedResponse {
+  new_operation: IOperationData;
+  oss: IOperationSchemaData;
+}
+
+/**
+ * Represents target {@link IOperation}.
+ */
+export interface ITargetOperation {
+  positions: IOperationPosition[];
+  target: OperationID;
+}
+
+/**
+ * Represents {@link IOperation} data, used in destruction process.
+ */
+export interface IOperationDeleteDTO extends ITargetOperation {
+  keep_constituents: boolean;
+  delete_schema: boolean;
+}
+
+/**
+ * Represents data response when creating {@link IRSForm} for Input {@link IOperation}.
+ */
+export interface IInputCreatedResponse {
+  new_schema: ILibraryItem;
+  oss: IOperationSchemaData;
+}
+
+/**
+ * Represents {@link IOperation} data, used in setInput process.
+ */
+export interface IInputUpdateDTO extends ITargetOperation {
+  input: LibraryItemID | null;
+}
+
+/**
+ * Represents {@link IOperation} data, used in update process.
+ */
+export interface IOperationUpdateDTO extends ITargetOperation {
+  item_data: {
+    alias: string;
+    title: string;
+    comment: string;
+  };
+  arguments: OperationID[] | undefined;
+  substitutions: ICstSubstitute[] | undefined;
+}
+
+/**
+ * Represents data, used relocating {@link IConstituenta}s between {@link ILibraryItem}s.
+ */
+export interface ICstRelocateDTO {
+  destination: LibraryItemID;
+  items: ConstituentaID[];
+}
+
+export const ossApi = {
+  baseKey: 'oss',
+
+  getOssQueryOptions: ({ itemID }: { itemID?: LibraryItemID }) => {
+    return queryOptions({
+      queryKey: [ossApi.baseKey, 'item', itemID],
+      staleTime: DELAYS.staleShort,
+      queryFn: meta =>
+        !itemID
+          ? undefined
+          : axiosGet<IOperationSchemaData>({
+              endpoint: `/api/oss/${itemID}/details`,
+              options: { signal: meta.signal }
+            })
+    });
+  },
+
+  updatePositions: ({
+    itemID,
+    positions,
+    isSilent
+  }: {
+    itemID: LibraryItemID;
+    positions: IOperationPosition[];
+    isSilent?: boolean;
+  }) =>
+    axiosPatch({
+      endpoint: `/api/oss/${itemID}/update-positions`,
+      request: {
+        data: { positions: positions },
+        successMessage: isSilent ? undefined : information.changesSaved
+      }
+    }),
+
+  operationCreate: ({ itemID, data }: { itemID: LibraryItemID; data: IOperationCreateDTO }) =>
+    axiosPost<IOperationCreateDTO, IOperationCreatedResponse>({
+      endpoint: `/api/oss/${itemID}/create-operation`,
+      request: {
+        data: data,
+        successMessage: response => information.newOperation(response.new_operation.alias)
+      }
+    }),
+  operationDelete: ({ itemID, data }: { itemID: LibraryItemID; data: IOperationDeleteDTO }) =>
+    axiosDelete<IOperationDeleteDTO, IOperationSchemaData>({
+      endpoint: `/api/oss/${itemID}/delete-operation`,
+      request: {
+        data: data,
+        successMessage: information.operationDestroyed
+      }
+    }),
+  inputCreate: ({ itemID, data }: { itemID: LibraryItemID; data: ITargetOperation }) =>
+    axiosPatch<ITargetOperation, IInputCreatedResponse>({
+      endpoint: `/api/oss/${itemID}/create-input`,
+      request: {
+        data: data,
+        successMessage: information.newLibraryItem
+      }
+    }),
+  inputUpdate: ({ itemID, data }: { itemID: LibraryItemID; data: IInputUpdateDTO }) =>
+    axiosPatch<IInputUpdateDTO, IOperationSchemaData>({
+      endpoint: `/api/oss/${itemID}/set-input`,
+      request: {
+        data: data,
+        successMessage: information.changesSaved
+      }
+    }),
+  operationUpdate: ({ itemID, data }: { itemID: LibraryItemID; data: IOperationUpdateDTO }) =>
+    axiosPatch<IOperationUpdateDTO, IOperationSchemaData>({
+      endpoint: `/api/oss/${itemID}/update-operation`,
+      request: {
+        data: data,
+        successMessage: information.changesSaved
+      }
+    }),
+  operationExecute: ({ itemID, data }: { itemID: LibraryItemID; data: ITargetOperation }) =>
+    axiosPost<ITargetOperation, IOperationSchemaData>({
+      endpoint: `/api/oss/${itemID}/execute-operation`,
+      request: {
+        data: data,
+        successMessage: information.operationExecuted
+      }
+    }),
+
+  relocateConstituents: ({ itemID, data }: { itemID: LibraryItemID; data: ICstRelocateDTO }) =>
+    axiosPost<ICstRelocateDTO, IOperationSchemaData>({
+      endpoint: `/api/oss/${itemID}/relocate-constituents`,
+      request: {
+        data: data,
+        successMessage: information.changesSaved
+      }
+    }),
+  getPredecessor: (data: ITargetCst) =>
+    axiosPost<ITargetCst, IConstituentaReference>({
+      endpoint: '/api/oss/get-predecessor',
+      request: { data: data }
+    })
+};

rsconcept/frontend/src/backend/oss/useFindPredecessor.tsx

@@ -0,0 +1,19 @@
+import { useMutation } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { IConstituentaReference, ITargetCst } from '@/models/rsform';
+
+import { ossApi } from './api';
+
+export const useFindPredecessor = () => {
+  const mutation = useMutation({
+    mutationKey: [ossApi.baseKey, 'find-predecessor'],
+    mutationFn: ossApi.getPredecessor
+  });
+  return {
+    findPredecessor: (
+      data: ITargetCst, //
+      onSuccess?: DataCallback<IConstituentaReference>
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/oss/useInputCreate.tsx

@@ -0,0 +1,32 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { libraryApi } from '@/backend/library/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { ILibraryItem, LibraryItemID } from '@/models/library';
+
+import { ITargetOperation, ossApi } from './api';
+
+export const useInputCreate = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [ossApi.baseKey, 'input-create'],
+    mutationFn: ossApi.inputCreate,
+    onSuccess: data => {
+      client.setQueryData(ossApi.getOssQueryOptions({ itemID: data.oss.id }).queryKey, data.oss);
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: libraryApi.libraryListKey }),
+        client.invalidateQueries({ queryKey: [rsformsApi.baseKey] })
+      ]);
+    }
+  });
+  return {
+    inputCreate: (
+      data: {
+        itemID: LibraryItemID; //
+        data: ITargetOperation;
+      },
+      onSuccess?: DataCallback<ILibraryItem>
+    ) => mutation.mutate(data, { onSuccess: response => onSuccess?.(response.new_schema) })
+  };
+};

rsconcept/frontend/src/backend/oss/useInputUpdate.tsx

@@ -0,0 +1,25 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { libraryApi } from '@/backend/library/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { LibraryItemID } from '@/models/library';
+
+import { IInputUpdateDTO, ossApi } from './api';
+
+export const useInputUpdate = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [ossApi.baseKey, 'input-update'],
+    mutationFn: ossApi.inputUpdate,
+    onSuccess: data => {
+      client.setQueryData(ossApi.getOssQueryOptions({ itemID: data.id }).queryKey, data);
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: libraryApi.libraryListKey }),
+        client.invalidateQueries({ queryKey: [rsformsApi.baseKey] })
+      ]);
+    }
+  });
+  return {
+    inputUpdate: (data: { itemID: LibraryItemID; data: IInputUpdateDTO }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/oss/useMutatingOss.tsx

@@ -0,0 +1,11 @@
+import { useIsMutating } from '@tanstack/react-query';
+
+import { libraryApi } from '@/backend/library/api';
+
+import { ossApi } from './api';
+
+export const useMutatingOss = () => {
+  const countLibrary = useIsMutating({ mutationKey: [libraryApi.baseKey] });
+  const countOss = useIsMutating({ mutationKey: [ossApi.baseKey] });
+  return countLibrary + countOss !== 0;
+};

rsconcept/frontend/src/backend/oss/useOSS.tsx

@@ -0,0 +1,34 @@
+import { useQuery, useSuspenseQuery } from '@tanstack/react-query';
+
+import { useLibrary, useLibrarySuspense } from '@/backend/library/useLibrary';
+import { LibraryItemID } from '@/models/library';
+import { OssLoader } from '@/models/OssLoader';
+
+import { queryClient } from '../queryClient';
+import { ossApi } from './api';
+
+export function useOss({ itemID }: { itemID?: LibraryItemID }) {
+  const { items: libraryItems, isLoading: libraryLoading } = useLibrary();
+  const { data, isLoading, error } = useQuery({
+    ...ossApi.getOssQueryOptions({ itemID })
+  });
+
+  const schema = data && !libraryLoading ? new OssLoader(data, libraryItems).produceOSS() : undefined;
+  return { schema: schema, isLoading: isLoading || libraryLoading, error: error };
+}
+
+export function useOssSuspense({ itemID }: { itemID: LibraryItemID }) {
+  const { items: libraryItems } = useLibrarySuspense();
+  const { data } = useSuspenseQuery({
+    ...ossApi.getOssQueryOptions({ itemID })
+  });
+  const schema = new OssLoader(data!, libraryItems).produceOSS();
+  return { schema };
+}
+
+export function prefetchOSS({ itemID }: { itemID?: LibraryItemID }) {
+  if (!itemID) {
+    return null;
+  }
+  return queryClient.prefetchQuery(ossApi.getOssQueryOptions({ itemID }));
+}

rsconcept/frontend/src/backend/oss/useOperationCreate.tsx

@@ -0,0 +1,30 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { LibraryItemID } from '@/models/library';
+import { IOperationData } from '@/models/oss';
+
+import { IOperationCreateDTO, ossApi } from './api';
+
+export const useOperationCreate = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [ossApi.baseKey, 'operation-create'],
+    mutationFn: ossApi.operationCreate,
+    onSuccess: data => {
+      client.setQueryData(ossApi.getOssQueryOptions({ itemID: data.oss.id }).queryKey, data.oss);
+      updateTimestamp(data.oss.id);
+    }
+  });
+  return {
+    operationCreate: (
+      data: {
+        itemID: LibraryItemID; //
+        data: IOperationCreateDTO;
+      },
+      onSuccess?: DataCallback<IOperationData>
+    ) => mutation.mutate(data, { onSuccess: response => onSuccess?.(response.new_operation) })
+  };
+};

rsconcept/frontend/src/backend/oss/useOperationDelete.tsx

@@ -0,0 +1,25 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { libraryApi } from '@/backend/library/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { LibraryItemID } from '@/models/library';
+
+import { IOperationDeleteDTO, ossApi } from './api';
+
+export const useOperationDelete = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [ossApi.baseKey, 'operation-delete'],
+    mutationFn: ossApi.operationDelete,
+    onSuccess: data => {
+      client.setQueryData(ossApi.getOssQueryOptions({ itemID: data.id }).queryKey, data);
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: libraryApi.libraryListKey }),
+        client.invalidateQueries({ queryKey: [rsformsApi.baseKey] })
+      ]);
+    }
+  });
+  return {
+    operationDelete: (data: { itemID: LibraryItemID; data: IOperationDeleteDTO }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/oss/useOperationExecute.tsx

@@ -0,0 +1,25 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { libraryApi } from '@/backend/library/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { LibraryItemID } from '@/models/library';
+
+import { ITargetOperation, ossApi } from './api';
+
+export const useOperationExecute = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [ossApi.baseKey, 'operation-execute'],
+    mutationFn: ossApi.operationExecute,
+    onSuccess: data => {
+      client.setQueryData(ossApi.getOssQueryOptions({ itemID: data.id }).queryKey, data);
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: libraryApi.libraryListKey }),
+        client.invalidateQueries({ queryKey: [rsformsApi.baseKey] })
+      ]);
+    }
+  });
+  return {
+    operationExecute: (data: { itemID: LibraryItemID; data: ITargetOperation }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/oss/useOperationUpdate.tsx

@@ -0,0 +1,35 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { libraryApi } from '@/backend/library/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { ILibraryItem, LibraryItemID } from '@/models/library';
+
+import { IOperationUpdateDTO, ossApi } from './api';
+
+export const useOperationUpdate = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [ossApi.baseKey, 'operation-update'],
+    mutationFn: ossApi.operationUpdate,
+    onSuccess: (data, variables) => {
+      client.setQueryData(ossApi.getOssQueryOptions({ itemID: data.id }).queryKey, data);
+      const schemaID = data.items.find(item => item.id === variables.data.target)?.result;
+      if (!schemaID) {
+        return;
+      }
+      client.setQueryData(libraryApi.libraryListKey, (prev: ILibraryItem[] | undefined) =>
+        !prev
+          ? undefined
+          : prev.map(item =>
+              item.id === schemaID ? { ...item, ...variables.data.item_data, time_update: Date() } : item
+            )
+      );
+      return client.invalidateQueries({
+        queryKey: rsformsApi.getRSFormQueryOptions({ itemID: schemaID }).queryKey
+      });
+    }
+  });
+  return {
+    operationUpdate: (data: { itemID: LibraryItemID; data: IOperationUpdateDTO }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/oss/useRelocateConstituents.tsx

@@ -0,0 +1,25 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { libraryApi } from '@/backend/library/api';
+import { rsformsApi } from '@/backend/rsform/api';
+import { LibraryItemID } from '@/models/library';
+
+import { ICstRelocateDTO, ossApi } from './api';
+
+export const useRelocateConstituents = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [ossApi.baseKey, 'relocate-constituents'],
+    mutationFn: ossApi.relocateConstituents,
+    onSuccess: data => {
+      client.setQueryData(ossApi.getOssQueryOptions({ itemID: data.id }).queryKey, data);
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: libraryApi.libraryListKey }),
+        client.invalidateQueries({ queryKey: [rsformsApi.baseKey] })
+      ]);
+    }
+  });
+  return {
+    relocateConstituents: (data: { itemID: LibraryItemID; data: ICstRelocateDTO }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/oss/useUpdatePositions.tsx

@@ -0,0 +1,26 @@
+import { useMutation } from '@tanstack/react-query';
+
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { LibraryItemID } from '@/models/library';
+import { IOperationPosition } from '@/models/oss';
+
+import { ossApi } from './api';
+
+export const useUpdatePositions = () => {
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [ossApi.baseKey, 'update-positions'],
+    mutationFn: ossApi.updatePositions,
+    onSuccess: (_, variables) => updateTimestamp(variables.itemID)
+  });
+  return {
+    updatePositions: (
+      data: {
+        itemID: LibraryItemID; //
+        positions: IOperationPosition[];
+        isSilent?: boolean;
+      },
+      onSuccess?: () => void
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/queryClient.ts

@@ -1,6 +1,8 @@
 import { QueryClient } from '@tanstack/react-query';
 import { AxiosError } from 'axios';
 
+import { DELAYS } from './configuration';
+
 declare module '@tanstack/react-query' {
   interface Register {
     defaultError: AxiosError;
@@ -10,9 +12,9 @@ declare module '@tanstack/react-query' {
 export const queryClient = new QueryClient({
   defaultOptions: {
     queries: {
-      staleTime: 5 * 60 * 1000,
-      gcTime: 24 * 60 * 60 * 1000,
-      retry: 3,
+      staleTime: DELAYS.staleDefault,
+      gcTime: DELAYS.garbageCollection,
+      retry: false,
       refetchOnWindowFocus: true,
       refetchOnMount: true,
       refetchOnReconnect: true

rsconcept/frontend/src/backend/rsform/api.ts

@@ -0,0 +1,224 @@
+import { queryOptions } from '@tanstack/react-query';
+
+import { axiosDelete, axiosGet, axiosPatch, axiosPost } from '@/backend/apiTransport';
+import { DELAYS } from '@/backend/configuration';
+import { LibraryItemID, VersionID } from '@/models/library';
+import { ICstSubstitute, ICstSubstitutions } from '@/models/oss';
+import {
+  ConstituentaID,
+  CstType,
+  IConstituentaList,
+  IConstituentaMeta,
+  IRSFormData,
+  ITargetCst,
+  TermForm
+} from '@/models/rsform';
+import { IExpressionParse } from '@/models/rslang';
+import { information } from '@/utils/labels';
+
+/**
+ * Represents data, used for uploading {@link IRSForm} as file.
+ */
+export interface IRSFormUploadDTO {
+  itemID: LibraryItemID;
+  load_metadata: boolean;
+  file: File;
+  fileName: string;
+}
+
+/**
+ * Represents {@link IConstituenta} data, used in creation process.
+ */
+export interface ICstCreateDTO {
+  alias: string;
+  cst_type: CstType;
+  definition_raw: string;
+  term_raw: string;
+  convention: string;
+  definition_formal: string;
+  term_forms: TermForm[];
+
+  insert_after: ConstituentaID | null;
+}
+
+/**
+ * Represents data response when creating {@link IConstituenta}.
+ */
+export interface ICstCreatedResponse {
+  new_cst: IConstituentaMeta;
+  schema: IRSFormData;
+}
+
+/**
+ * Represents data, used in updating persistent attributes in {@link IConstituenta}.
+ */
+export interface ICstUpdateDTO {
+  target: ConstituentaID;
+  item_data: {
+    convention?: string;
+    definition_formal?: string;
+    definition_raw?: string;
+    term_raw?: string;
+    term_forms?: TermForm[];
+  };
+}
+
+/**
+ * Represents data, used in renaming {@link IConstituenta}.
+ */
+export interface ICstRenameDTO {
+  alias: string;
+  cst_type: CstType;
+  target: ConstituentaID;
+}
+
+/**
+ * Represents data, used in ordering a list of {@link IConstituenta}.
+ */
+export interface ICstMoveDTO {
+  items: ConstituentaID[];
+  move_to: number; // Note: 0-base index
+}
+
+/**
+ * Represents data response when creating producing structure of {@link IConstituenta}.
+ */
+export interface IProduceStructureResponse {
+  cst_list: ConstituentaID[];
+  schema: IRSFormData;
+}
+
+/**
+ * Represents input data for inline synthesis.
+ */
+export interface IInlineSynthesisDTO {
+  receiver: LibraryItemID;
+  source: LibraryItemID;
+  items: ConstituentaID[];
+  substitutions: ICstSubstitute[];
+}
+
+/**
+ * Represents {@link IConstituenta} data, used for checking expression.
+ */
+export interface ICheckConstituentaDTO {
+  alias: string;
+  cst_type: CstType;
+  definition_formal: string;
+}
+
+export const rsformsApi = {
+  baseKey: 'rsform',
+
+  getRSFormQueryOptions: ({ itemID, version }: { itemID?: LibraryItemID; version?: VersionID }) => {
+    return queryOptions({
+      queryKey: [rsformsApi.baseKey, 'item', itemID, version ?? ''],
+      staleTime: DELAYS.staleShort,
+      queryFn: meta =>
+        !itemID
+          ? undefined
+          : axiosGet<IRSFormData>({
+              endpoint: version ? `/api/library/${itemID}/versions/${version}` : `/api/rsforms/${itemID}/details`,
+              options: { signal: meta.signal }
+            })
+    });
+  },
+
+  download: ({ itemID, version }: { itemID: LibraryItemID; version?: VersionID }) =>
+    axiosGet<Blob>({
+      endpoint: version ? `/api/versions/${version}/export-file` : `/api/rsforms/${itemID}/export-trs`,
+      options: { responseType: 'blob' }
+    }),
+  upload: (data: IRSFormUploadDTO) =>
+    axiosPatch<IRSFormUploadDTO, IRSFormData>({
+      endpoint: `/api/rsforms/${data.itemID}/load-trs`,
+      request: {
+        data: data,
+        successMessage: information.uploadSuccess
+      },
+      options: {
+        headers: {
+          'Content-Type': 'multipart/form-data'
+        }
+      }
+    }),
+
+  cstCreate: ({ itemID, data }: { itemID: LibraryItemID; data: ICstCreateDTO }) =>
+    axiosPost<ICstCreateDTO, ICstCreatedResponse>({
+      endpoint: `/api/rsforms/${itemID}/create-cst`,
+      request: {
+        data: data,
+        successMessage: response => information.newConstituent(response.new_cst.alias)
+      }
+    }),
+  cstUpdate: ({ itemID, data }: { itemID: LibraryItemID; data: ICstUpdateDTO }) =>
+    axiosPatch<ICstUpdateDTO, IConstituentaMeta>({
+      endpoint: `/api/rsforms/${itemID}/update-cst`,
+      request: {
+        data: data,
+        successMessage: information.changesSaved
+      }
+    }),
+  cstDelete: ({ itemID, data }: { itemID: LibraryItemID; data: IConstituentaList }) =>
+    axiosDelete<IConstituentaList, IRSFormData>({
+      endpoint: `/api/rsforms/${itemID}/delete-multiple-cst`,
+      request: {
+        data: data,
+        successMessage: information.constituentsDestroyed(data.items.length)
+      }
+    }),
+  cstRename: ({ itemID, data }: { itemID: LibraryItemID; data: ICstRenameDTO }) =>
+    axiosPatch<ICstRenameDTO, ICstCreatedResponse>({
+      endpoint: `/api/rsforms/${itemID}/rename-cst`,
+      request: {
+        data: data,
+        successMessage: information.changesSaved
+      }
+    }),
+  cstSubstitute: ({ itemID, data }: { itemID: LibraryItemID; data: ICstSubstitutions }) =>
+    axiosPatch<ICstSubstitutions, IRSFormData>({
+      endpoint: `/api/rsforms/${itemID}/substitute`,
+      request: {
+        data: data,
+        successMessage: information.substituteSingle
+      }
+    }),
+  cstMove: ({ itemID, data }: { itemID: LibraryItemID; data: ICstMoveDTO }) =>
+    axiosPatch<ICstMoveDTO, IRSFormData>({
+      endpoint: `/api/rsforms/${itemID}/move-cst`,
+      request: { data: data }
+    }),
+
+  produceStructure: ({ itemID, data }: { itemID: LibraryItemID; data: ITargetCst }) =>
+    axiosPost<ITargetCst, IProduceStructureResponse>({
+      endpoint: `/api/rsforms/${itemID}/produce-structure`,
+      request: {
+        data: data,
+        successMessage: response => information.addedConstituents(response.cst_list.length)
+      }
+    }),
+  inlineSynthesis: ({ itemID, data }: { itemID: LibraryItemID; data: IInlineSynthesisDTO }) =>
+    axiosPost<IInlineSynthesisDTO, IRSFormData>({
+      endpoint: `/api/rsforms/${itemID}/inline-synthesis`,
+      request: {
+        data: data,
+        successMessage: information.inlineSynthesisComplete
+      }
+    }),
+  restoreOrder: ({ itemID }: { itemID: LibraryItemID }) =>
+    axiosPatch<undefined, IRSFormData>({
+      endpoint: `/api/rsforms/${itemID}/restore-order`,
+      request: { successMessage: information.reorderComplete }
+    }),
+  resetAliases: ({ itemID }: { itemID: LibraryItemID }) =>
+    axiosPatch<undefined, IRSFormData>({
+      endpoint: `/api/rsforms/${itemID}/reset-aliases`,
+      request: { successMessage: information.reindexComplete }
+    }),
+
+  checkConstituenta: ({ itemID, data }: { itemID: LibraryItemID; data: ICheckConstituentaDTO }) =>
+    axiosPost<ICheckConstituentaDTO, IExpressionParse>({
+      endpoint: `/api/rsforms/${itemID}/check-constituenta`,
+      request: { data: data }
+    })
+};

rsconcept/frontend/src/backend/rsform/useCheckConstituenta.tsx

@@ -0,0 +1,25 @@
+import { useMutation } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { LibraryItemID } from '@/models/library';
+import { IExpressionParse } from '@/models/rslang';
+
+import { ICheckConstituentaDTO, rsformsApi } from './api';
+
+export const useCheckConstituenta = () => {
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'check-constituenta'],
+    mutationFn: rsformsApi.checkConstituenta
+  });
+  return {
+    checkConstituenta: (
+      data: {
+        itemID: LibraryItemID; //
+        data: ICheckConstituentaDTO;
+      },
+      onSuccess?: DataCallback<IExpressionParse>
+    ) => mutation.mutate(data, { onSuccess }),
+    isPending: mutation.isPending,
+    error: mutation.error
+  };
+};

rsconcept/frontend/src/backend/rsform/useCstCreate.tsx

@@ -0,0 +1,39 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { ossApi } from '@/backend/oss/api';
+import { LibraryItemID } from '@/models/library';
+import { IConstituentaMeta } from '@/models/rsform';
+
+import { ICstCreateDTO, rsformsApi } from './api';
+
+export const useCstCreate = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'create-cst'],
+    mutationFn: rsformsApi.cstCreate,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.schema.id }).queryKey, data.schema);
+      updateTimestamp(data.schema.id);
+
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({
+          queryKey: [rsformsApi.baseKey],
+          predicate: query => query.queryKey.length > 2 && query.queryKey[2] !== data.schema.id
+        })
+      ]);
+    }
+  });
+  return {
+    cstCreate: (
+      data: {
+        itemID: LibraryItemID; //
+        data: ICstCreateDTO;
+      },
+      onSuccess?: DataCallback<IConstituentaMeta>
+    ) => mutation.mutate(data, { onSuccess: response => onSuccess?.(response.new_cst) })
+  };
+};

rsconcept/frontend/src/backend/rsform/useCstDelete.tsx

@@ -0,0 +1,38 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { ossApi } from '@/backend/oss/api';
+import { LibraryItemID } from '@/models/library';
+import { IConstituentaList } from '@/models/rsform';
+
+import { rsformsApi } from './api';
+
+export const useCstDelete = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'delete-multiple-cst'],
+    mutationFn: rsformsApi.cstDelete,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.id }).queryKey, data);
+      updateTimestamp(data.id);
+
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({
+          queryKey: [rsformsApi.baseKey],
+          predicate: query => query.queryKey.length > 2 && query.queryKey[2] !== data.id
+        })
+      ]);
+    }
+  });
+  return {
+    cstDelete: (
+      data: {
+        itemID: LibraryItemID; //
+        data: IConstituentaList;
+      },
+      onSuccess?: () => void
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/rsform/useCstMove.tsx

@@ -0,0 +1,28 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { LibraryItemID } from '@/models/library';
+
+import { ICstMoveDTO, rsformsApi } from './api';
+
+export const useCstMove = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'move-cst'],
+    mutationFn: rsformsApi.cstMove,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.id }).queryKey, data);
+      updateTimestamp(data.id);
+    }
+  });
+  return {
+    cstMove: (
+      data: {
+        itemID: LibraryItemID; //
+        data: ICstMoveDTO;
+      },
+      onSuccess?: () => void
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/rsform/useCstRename.tsx

@@ -0,0 +1,31 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { ossApi } from '@/backend/oss/api';
+import { LibraryItemID } from '@/models/library';
+
+import { ICstRenameDTO, rsformsApi } from './api';
+
+export const useCstRename = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'rename-cst'],
+    mutationFn: rsformsApi.cstRename,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.schema.id }).queryKey, data.schema);
+      updateTimestamp(data.schema.id);
+
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({
+          queryKey: [rsformsApi.baseKey],
+          predicate: query => query.queryKey.length > 2 && query.queryKey[2] !== data.schema.id
+        })
+      ]);
+    }
+  });
+  return {
+    cstRename: (data: { itemID: LibraryItemID; data: ICstRenameDTO }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/rsform/useCstSubstitute.tsx

@@ -0,0 +1,38 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { ossApi } from '@/backend/oss/api';
+import { LibraryItemID } from '@/models/library';
+import { ICstSubstitutions } from '@/models/oss';
+
+import { rsformsApi } from './api';
+
+export const useCstSubstitute = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'substitute-cst'],
+    mutationFn: rsformsApi.cstSubstitute,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.id }).queryKey, data);
+      updateTimestamp(data.id);
+
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({
+          queryKey: [rsformsApi.baseKey],
+          predicate: query => query.queryKey.length > 2 && query.queryKey[2] !== data.id
+        })
+      ]);
+    }
+  });
+  return {
+    cstSubstitute: (
+      data: {
+        itemID: LibraryItemID; //
+        data: ICstSubstitutions;
+      },
+      onSuccess?: () => void
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/rsform/useCstUpdate.tsx

@@ -0,0 +1,38 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { ossApi } from '@/backend/oss/api';
+import { LibraryItemID } from '@/models/library';
+
+import { ICstUpdateDTO, rsformsApi } from './api';
+
+export const useCstUpdate = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'update-cst'],
+    mutationFn: rsformsApi.cstUpdate,
+    onSuccess: (newCst, variables) => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: variables.itemID }).queryKey, prev =>
+        !prev
+          ? undefined
+          : {
+              ...prev,
+              items: prev.items.map(item => (item.id === newCst.id ? { ...item, ...newCst } : item))
+            }
+      );
+      updateTimestamp(variables.itemID);
+
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({
+          queryKey: [rsformsApi.baseKey],
+          predicate: query => query.queryKey.length > 2 && query.queryKey[2] !== variables.itemID
+        })
+      ]);
+    }
+  });
+  return {
+    cstUpdate: (data: { itemID: LibraryItemID; data: ICstUpdateDTO }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/rsform/useDownloadRSForm.tsx

@@ -0,0 +1,21 @@
+import { useMutation } from '@tanstack/react-query';
+
+import { LibraryItemID, VersionID } from '@/models/library';
+
+import { rsformsApi } from './api';
+
+export const useDownloadRSForm = () => {
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'download'],
+    mutationFn: rsformsApi.download
+  });
+  return {
+    download: (
+      data: {
+        itemID: LibraryItemID; //
+        version?: VersionID;
+      },
+      onSuccess?: (data: Blob) => void
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/rsform/useInlineSynthesis.tsx

@@ -0,0 +1,39 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { ossApi } from '@/backend/oss/api';
+import { LibraryItemID } from '@/models/library';
+import { IRSFormData } from '@/models/rsform';
+
+import { IInlineSynthesisDTO, rsformsApi } from './api';
+
+export const useInlineSynthesis = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'inline-synthesis'],
+    mutationFn: rsformsApi.inlineSynthesis,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.id }).queryKey, data);
+      updateTimestamp(data.id);
+
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({
+          queryKey: [rsformsApi.baseKey],
+          predicate: query => query.queryKey.length > 2 && query.queryKey[2] !== data.id
+        })
+      ]);
+    }
+  });
+  return {
+    inlineSynthesis: (
+      data: {
+        itemID: LibraryItemID; //
+        data: IInlineSynthesisDTO;
+      },
+      onSuccess?: DataCallback<IRSFormData>
+    ) => mutation.mutate(data, { onSuccess })
+  };
+};

rsconcept/frontend/src/backend/rsform/useMutatingRSForm.tsx

@@ -0,0 +1,11 @@
+import { useIsMutating } from '@tanstack/react-query';
+
+import { libraryApi } from '@/backend/library/api';
+
+import { rsformsApi } from './api';
+
+export const useMutatingRSForm = () => {
+  const countLibrary = useIsMutating({ mutationKey: [libraryApi.baseKey] });
+  const countRsform = useIsMutating({ mutationKey: [rsformsApi.baseKey] });
+  return countLibrary + countRsform !== 0;
+};

rsconcept/frontend/src/backend/rsform/useProduceStructure.tsx

@@ -0,0 +1,39 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { DataCallback } from '@/backend/apiTransport';
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { ossApi } from '@/backend/oss/api';
+import { LibraryItemID } from '@/models/library';
+import { ConstituentaID, ITargetCst } from '@/models/rsform';
+
+import { rsformsApi } from './api';
+
+export const useProduceStructure = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'produce-structure'],
+    mutationFn: rsformsApi.produceStructure,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.schema.id }).queryKey, data.schema);
+      updateTimestamp(data.schema.id);
+
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({
+          queryKey: [rsformsApi.baseKey],
+          predicate: query => query.queryKey.length > 2 && query.queryKey[2] !== data.schema.id
+        })
+      ]);
+    }
+  });
+  return {
+    produceStructure: (
+      data: {
+        itemID: LibraryItemID; //
+        data: ITargetCst;
+      },
+      onSuccess?: DataCallback<ConstituentaID[]>
+    ) => mutation.mutate(data, { onSuccess: response => onSuccess?.(response.cst_list) })
+  };
+};

rsconcept/frontend/src/backend/rsform/useRSForm.tsx

@@ -0,0 +1,31 @@
+import { useQuery, useSuspenseQuery } from '@tanstack/react-query';
+
+import { LibraryItemID, VersionID } from '@/models/library';
+import { RSFormLoader } from '@/models/RSFormLoader';
+
+import { queryClient } from '../queryClient';
+import { rsformsApi } from './api';
+
+export function useRSForm({ itemID, version }: { itemID?: LibraryItemID; version?: VersionID }) {
+  const { data, isLoading, error } = useQuery({
+    ...rsformsApi.getRSFormQueryOptions({ itemID, version })
+  });
+
+  const schema = data ? new RSFormLoader(data).produceRSForm() : undefined;
+  return { schema, isLoading, error };
+}
+
+export function useRSFormSuspense({ itemID, version }: { itemID: LibraryItemID; version?: VersionID }) {
+  const { data } = useSuspenseQuery({
+    ...rsformsApi.getRSFormQueryOptions({ itemID, version })
+  });
+  const schema = new RSFormLoader(data!).produceRSForm();
+  return { schema };
+}
+
+export function prefetchRSForm({ itemID, version }: { itemID?: LibraryItemID; version?: VersionID }) {
+  if (!itemID) {
+    return null;
+  }
+  return queryClient.prefetchQuery(rsformsApi.getRSFormQueryOptions({ itemID, version }));
+}

rsconcept/frontend/src/backend/rsform/useRSForms.tsx

@@ -0,0 +1,23 @@
+import { useQueries } from '@tanstack/react-query';
+
+import { LibraryItemID } from '@/models/library';
+import { RSFormLoader } from '@/models/RSFormLoader';
+
+import { DELAYS } from '../configuration';
+import { rsformsApi } from './api';
+
+export function useRSForms(itemIDs: LibraryItemID[]) {
+  const results = useQueries({
+    queries: itemIDs.map(itemID => ({
+      ...rsformsApi.getRSFormQueryOptions({ itemID }),
+      enabled: itemIDs.length > 0,
+      staleTime: DELAYS.staleShort
+    }))
+  });
+
+  const schemas = results
+    .map(result => result.data)
+    .filter(data => data !== undefined)
+    .map(data => new RSFormLoader(data).produceRSForm());
+  return schemas;
+}

rsconcept/frontend/src/backend/rsform/useResetAliases.tsx

@@ -0,0 +1,31 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { ossApi } from '@/backend/oss/api';
+import { LibraryItemID } from '@/models/library';
+
+import { rsformsApi } from './api';
+
+export const useResetAliases = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'reset-aliases'],
+    mutationFn: rsformsApi.resetAliases,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.id }).queryKey, data);
+      updateTimestamp(data.id);
+
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({
+          queryKey: [rsformsApi.baseKey],
+          predicate: query => query.queryKey.length > 2 && query.queryKey[2] !== data.id
+        })
+      ]);
+    }
+  });
+  return {
+    resetAliases: (data: { itemID: LibraryItemID }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/rsform/useRestoreOrder.tsx

@@ -0,0 +1,22 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { useUpdateTimestamp } from '@/backend/library/useUpdateTimestamp';
+import { LibraryItemID } from '@/models/library';
+
+import { rsformsApi } from './api';
+
+export const useRestoreOrder = () => {
+  const client = useQueryClient();
+  const { updateTimestamp } = useUpdateTimestamp();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'restore-order'],
+    mutationFn: rsformsApi.restoreOrder,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.id }).queryKey, data);
+      updateTimestamp(data.id);
+    }
+  });
+  return {
+    restoreOrder: (data: { itemID: LibraryItemID }) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/rsform/useUploadTRS.tsx

@@ -0,0 +1,32 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { libraryApi } from '@/backend/library/api';
+import { ossApi } from '@/backend/oss/api';
+import { ILibraryItem } from '@/models/library';
+
+import { IRSFormUploadDTO, rsformsApi } from './api';
+
+export const useUploadTRS = () => {
+  const client = useQueryClient();
+  const mutation = useMutation({
+    mutationKey: [rsformsApi.baseKey, 'load-trs'],
+    mutationFn: rsformsApi.upload,
+    onSuccess: data => {
+      client.setQueryData(rsformsApi.getRSFormQueryOptions({ itemID: data.id }).queryKey, data);
+      client.setQueryData(libraryApi.libraryListKey, (prev: ILibraryItem[] | undefined) =>
+        prev?.map(item => (item.id === data.id ? data : item))
+      );
+
+      return Promise.allSettled([
+        client.invalidateQueries({ queryKey: [ossApi.baseKey] }),
+        client.invalidateQueries({
+          queryKey: [rsformsApi.baseKey],
+          predicate: query => query.queryKey.length > 2 && query.queryKey[2] !== data.id
+        })
+      ]);
+    }
+  });
+  return {
+    upload: (data: IRSFormUploadDTO) => mutation.mutate(data)
+  };
+};

rsconcept/frontend/src/backend/rsforms.ts

@@ -1,158 +0,0 @@
-/**
- * Endpoints: rsforms.
- */
-
-import { ILibraryCreateData, ILibraryItem } from '@/models/library';
-import { ICstSubstituteData } from '@/models/oss';
-import {
-  ICheckConstituentaData,
-  IConstituentaList,
-  IConstituentaMeta,
-  ICstCreateData,
-  ICstCreatedResponse,
-  ICstMovetoData,
-  ICstRenameData,
-  ICstUpdateData,
-  IInlineSynthesisData,
-  IProduceStructureResponse,
-  IRSFormData,
-  IRSFormUploadData,
-  ITargetCst
-} from '@/models/rsform';
-import { IExpressionParse } from '@/models/rslang';
-
-import { AxiosGet, AxiosPatch, AxiosPost, FrontExchange, FrontPull } from './apiTransport';
-
-export function postRSFormFromFile(request: FrontExchange<ILibraryCreateData, ILibraryItem>) {
-  AxiosPost({
-    endpoint: '/api/rsforms/create-detailed',
-    request: request,
-    options: {
-      headers: {
-        'Content-Type': 'multipart/form-data'
-      }
-    }
-  });
-}
-
-export function getRSFormDetails(target: string, version: string, request: FrontPull<IRSFormData>) {
-  if (!version) {
-    AxiosGet({
-      endpoint: `/api/rsforms/${target}/details`,
-      request: request
-    });
-  } else {
-    AxiosGet({
-      endpoint: `/api/library/${target}/versions/${version}`,
-      request: request
-    });
-  }
-}
-
-export function getTRSFile(target: string, version: string, request: FrontPull<Blob>) {
-  if (!version) {
-    AxiosGet({
-      endpoint: `/api/rsforms/${target}/export-trs`,
-      request: request,
-      options: { responseType: 'blob' }
-    });
-  } else {
-    AxiosGet({
-      endpoint: `/api/versions/${version}/export-file`,
-      request: request,
-      options: { responseType: 'blob' }
-    });
-  }
-}
-
-export function postCreateConstituenta(schema: string, request: FrontExchange<ICstCreateData, ICstCreatedResponse>) {
-  AxiosPost({
-    endpoint: `/api/rsforms/${schema}/create-cst`,
-    request: request
-  });
-}
-
-export function patchUpdateConstituenta(schema: string, request: FrontExchange<ICstUpdateData, IConstituentaMeta>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/${schema}/update-cst`,
-    request: request
-  });
-}
-
-export function patchDeleteConstituenta(schema: string, request: FrontExchange<IConstituentaList, IRSFormData>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/${schema}/delete-multiple-cst`,
-    request: request
-  });
-}
-
-export function patchRenameConstituenta(schema: string, request: FrontExchange<ICstRenameData, ICstCreatedResponse>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/${schema}/rename-cst`,
-    request: request
-  });
-}
-
-export function patchProduceStructure(schema: string, request: FrontExchange<ITargetCst, IProduceStructureResponse>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/${schema}/produce-structure`,
-    request: request
-  });
-}
-
-export function patchSubstituteConstituents(schema: string, request: FrontExchange<ICstSubstituteData, IRSFormData>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/${schema}/substitute`,
-    request: request
-  });
-}
-
-export function patchMoveConstituenta(schema: string, request: FrontExchange<ICstMovetoData, IRSFormData>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/${schema}/move-cst`,
-    request: request
-  });
-}
-
-export function postCheckConstituenta(
-  schema: string,
-  request: FrontExchange<ICheckConstituentaData, IExpressionParse>
-) {
-  AxiosPost({
-    endpoint: `/api/rsforms/${schema}/check-constituenta`,
-    request: request
-  });
-}
-
-export function patchResetAliases(target: string, request: FrontPull<IRSFormData>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/${target}/reset-aliases`,
-    request: request
-  });
-}
-
-export function patchRestoreOrder(target: string, request: FrontPull<IRSFormData>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/${target}/restore-order`,
-    request: request
-  });
-}
-
-export function patchUploadTRS(target: string, request: FrontExchange<IRSFormUploadData, IRSFormData>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/${target}/load-trs`,
-    request: request,
-    options: {
-      headers: {
-        'Content-Type': 'multipart/form-data'
-      }
-    }
-  });
-}
-
-export function patchInlineSynthesis(request: FrontExchange<IInlineSynthesisData, IRSFormData>) {
-  AxiosPatch({
-    endpoint: `/api/rsforms/inline-synthesis`,
-    request: request
-  });
-}

rsconcept/frontend/src/backend/users/api.ts

@@ -1,8 +1,9 @@
 import { queryOptions } from '@tanstack/react-query';
 
+import { axiosGet, axiosPatch, axiosPost } from '@/backend/apiTransport';
+import { DELAYS } from '@/backend/configuration';
 import { IUser, IUserInfo, IUserProfile, IUserSignupData } from '@/models/user';
-
-import { axiosInstance } from '../apiConfiguration';
+import { information } from '@/utils/labels';
 
 /**
  * Represents user data, intended to update user profile in persistent storage.
@@ -14,27 +15,39 @@ export const usersApi = {
   getUsersQueryOptions: () =>
     queryOptions({
       queryKey: [usersApi.baseKey, 'list'],
+      staleTime: DELAYS.staleMedium,
       queryFn: meta =>
-        axiosInstance
-          .get<IUserInfo[]>('/users/api/active-users', {
-            signal: meta.signal
+        axiosGet<IUserInfo[]>({
+          endpoint: '/users/api/active-users',
+          options: { signal: meta.signal }
         })
-          .then(response => response.data),
-      placeholderData: []
     }),
   getProfileQueryOptions: () =>
     queryOptions({
       queryKey: [usersApi.baseKey, 'profile'],
+      staleTime: DELAYS.staleShort,
       queryFn: meta =>
-        axiosInstance
-          .get<IUserProfile>('/users/api/profile', {
-            signal: meta.signal
+        axiosGet<IUserProfile>({
+          endpoint: '/users/api/profile',
+          options: { signal: meta.signal }
         })
-          .then(response => response.data)
     }),
 
-  signup: (data: IUserSignupData) => axiosInstance.post('/users/api/signup', data),
-  updateProfile: (data: IUpdateProfileDTO) => axiosInstance.patch('/users/api/profile', data)
-};
+  signup: (data: IUserSignupData) =>
+    axiosPost<IUserSignupData, IUserProfile>({
+      endpoint: '/users/api/signup',
+      request: {
+        data: data,
+        successMessage: createdUser => information.newUser(createdUser.username)
+      }
+    }),
 
-//DataCallback<IUserProfile>
+  updateProfile: (data: IUpdateProfileDTO) =>
+    axiosPatch<IUpdateProfileDTO, IUserProfile>({
+      endpoint: '/users/api/profile',
+      request: {
+        data: data,
+        successMessage: information.changesSaved
+      }
+    })
+};

rsconcept/frontend/src/backend/users/useProfile.tsx

@@ -1,5 +1,7 @@
 import { useQuery, useSuspenseQuery } from '@tanstack/react-query';
 
+import { queryClient } from '@/backend/queryClient';
+
 import { usersApi } from './api';
 
 export function useProfile() {
@@ -19,3 +21,7 @@ export function useProfileSuspense() {
   });
   return { profile };
 }
+
+export function prefetchProfile() {
+  return queryClient.prefetchQuery(usersApi.getProfileQueryOptions());
+}

rsconcept/frontend/src/backend/users/useSignup.tsx

@@ -1,20 +1,21 @@
 import { useMutation, useQueryClient } from '@tanstack/react-query';
 
+import { DataCallback } from '@/backend/apiTransport';
 import { usersApi } from '@/backend/users/api';
 import { IUserProfile, IUserSignupData } from '@/models/user';
 
-import { DataCallback } from '../apiTransport';
-
 export const useSignup = () => {
-  const queryClient = useQueryClient();
+  const client = useQueryClient();
   const mutation = useMutation({
     mutationKey: ['signup'],
     mutationFn: usersApi.signup,
-    onSuccess: () => queryClient.invalidateQueries({ queryKey: [usersApi.baseKey] })
+    onSuccess: () => client.invalidateQueries({ queryKey: usersApi.getUsersQueryOptions().queryKey })
   });
   return {
-    signup: (data: IUserSignupData, onSuccess?: DataCallback<IUserProfile>) =>
-      mutation.mutate(data, { onSuccess: response => onSuccess?.(response.data as IUserProfile) }),
+    signup: (
+      data: IUserSignupData, //
+      onSuccess?: DataCallback<IUserProfile>
+    ) => mutation.mutate(data, { onSuccess }),
     isPending: mutation.isPending,
     error: mutation.error,
     reset: mutation.reset

rsconcept/frontend/src/backend/users/useUpdateProfile.tsx

@@ -1,21 +1,19 @@
 import { useMutation, useQueryClient } from '@tanstack/react-query';
 
-import { IUserProfile } from '@/models/user';
-
 import { IUpdateProfileDTO, usersApi } from './api';
 
-// TODO: reload users / optimistic update
-
 export const useUpdateProfile = () => {
-  const queryClient = useQueryClient();
+  const client = useQueryClient();
   const mutation = useMutation({
     mutationKey: ['update-profile'],
     mutationFn: usersApi.updateProfile,
-    onSuccess: () => queryClient.invalidateQueries({ queryKey: [usersApi.baseKey] })
+    onSuccess: data => {
+      client.setQueryData(usersApi.getProfileQueryOptions().queryKey, data);
+      return client.invalidateQueries({ queryKey: usersApi.getUsersQueryOptions().queryKey });
+    }
   });
   return {
-    updateProfile: (data: IUpdateProfileDTO, onSuccess?: (newUser: IUserProfile) => void) =>
-      mutation.mutate(data, { onSuccess: response => onSuccess?.(response.data as IUserProfile) }),
+    updateProfile: (data: IUpdateProfileDTO) => mutation.mutate(data),
     isPending: mutation.isPending,
     error: mutation.error,
     reset: mutation.reset

rsconcept/frontend/src/backend/users/useUsers.tsx

@@ -1,11 +1,12 @@
 import { useQuery, useSuspenseQuery } from '@tanstack/react-query';
 
+import { queryClient } from '@/backend/queryClient';
+
 import { usersApi } from './api';
 
 export function useUsersSuspense() {
   const { data: users } = useSuspenseQuery({
-    ...usersApi.getUsersQueryOptions(),
-    initialData: []
+    ...usersApi.getUsersQueryOptions()
   });
   return { users };
 }
@@ -16,3 +17,7 @@ export function useUsers() {
   });
   return { users: users ?? [] };
 }
+
+export function prefetchUsers() {
+  return queryClient.prefetchQuery(usersApi.getUsersQueryOptions());
+}

rsconcept/frontend/src/backend/versions.ts

@@ -1,30 +0,0 @@
-/**
- * Endpoints: versions.
- */
-
-import { IVersionData } from '@/models/library';
-import { IRSFormData } from '@/models/rsform';
-
-import { AxiosDelete, AxiosPatch, FrontAction, FrontPull, FrontPush } from './apiTransport';
-
-export function patchVersion(target: string, request: FrontPush<IVersionData>) {
-  // title: `Version id=${target}`,
-  AxiosPatch({
-    endpoint: `/api/versions/${target}`,
-    request: request
-  });
-}
-
-export function patchRestoreVersion(target: string, request: FrontPull<IRSFormData>) {
-  AxiosPatch({
-    endpoint: `/api/versions/${target}/restore`,
-    request: request
-  });
-}
-
-export function deleteVersion(target: string, request: FrontAction) {
-  AxiosDelete({
-    endpoint: `/api/versions/${target}`,
-    request: request
-  });
-}

rsconcept/frontend/src/components/ExpectedAnonymous.tsx

@@ -1,12 +1,11 @@
+import { useConceptNavigation } from '@/app/Navigation/NavigationContext';
 import { urls } from '@/app/urls';
-import { useAuth } from '@/backend/auth/useAuth';
+import { useAuthSuspense } from '@/backend/auth/useAuth';
 import { useLogout } from '@/backend/auth/useLogout';
-import { useConceptNavigation } from '@/context/NavigationContext';
-
-import TextURL from '../ui/TextURL';
+import TextURL from '@/components/ui/TextURL';
 
 function ExpectedAnonymous() {
-  const { user } = useAuth();
+  const { user } = useAuthSuspense();
   const { logout } = useLogout();
   const router = useConceptNavigation();
 
@@ -16,7 +15,7 @@ function ExpectedAnonymous() {
 
   return (
     <div className='cc-fade-in flex flex-col items-center gap-3 py-6'>
-      <p className='font-semibold'>{`Вы вошли в систему как ${user?.username ?? ''}`}</p>
+      <p className='font-semibold'>{`Вы вошли в систему как ${user.username}`}</p>
       <div className='flex gap-3'>
         <TextURL text='Новая схема' href='/library/create' />
         <span> | </span>

rsconcept/frontend/src/components/RSInput/RSInput.tsx

@@ -47,7 +47,7 @@ interface RSInputProps
 const RSInput = forwardRef<ReactCodeMirrorRef, RSInputProps>(
   (
     {
-      id, // prettier: split lines
+      id, //
       label,
       disabled,
       noTooltip,

rsconcept/frontend/src/components/RequireAuth.tsx

@@ -1,19 +1,12 @@
 'use client';
 
-import { useAuth } from '@/backend/auth/useAuth';
-
-import Loader from '../ui/Loader';
-import TextURL from '../ui/TextURL';
+import { useAuthSuspense } from '@/backend/auth/useAuth';
+import TextURL from '@/components/ui/TextURL';
 
 function RequireAuth({ children }: React.PropsWithChildren) {
-  const { user, isLoading } = useAuth();
+  const { isAnonymous } = useAuthSuspense();
 
-  if (isLoading) {
-    return <Loader key='auth-loader' />;
-  }
-  if (user) {
-    return <>{children}</>;
-  } else {
+  if (isAnonymous) {
     return (
       <div key='auth-no-user' className='flex flex-col items-center gap-1 mt-2'>
         <p className='mb-2'>Пожалуйста войдите в систему</p>
@@ -23,6 +16,7 @@ function RequireAuth({ children }: React.PropsWithChildren) {
       </div>
     );
   }
+  return <>{children}</>;
 }
 
 export default RequireAuth;

rsconcept/frontend/src/components/info/BadgeConstituenta.tsx

@@ -1,12 +1,11 @@
 import clsx from 'clsx';
 
+import { CProps } from '@/components/props';
 import { CstClass, IConstituenta } from '@/models/rsform';
 import { useTooltipsStore } from '@/stores/tooltips';
 import { APP_COLORS, colorFgCstStatus } from '@/styling/color';
 import { globals } from '@/utils/constants';
 
-import { CProps } from '../props';
-
 interface BadgeConstituentaProps extends CProps.Styling {
   /** Prefix for tooltip ID. */
   prefixID?: string;

rsconcept/frontend/src/components/info/BadgeGrammeme.tsx

@@ -16,7 +16,7 @@ function BadgeGrammeme({ grammeme }: BadgeGrammemeProps) {
   return (
     <div
       className={clsx(
-        'min-w-[3rem]', // prettier: split lines
+        'min-w-[3rem]', //
         'px-1',
         'border rounded-md',
         'text-sm font-medium text-center whitespace-nowrap'

rsconcept/frontend/src/components/info/BadgeHelp.tsx

@@ -1,14 +1,13 @@
 import React, { Suspense } from 'react';
 
+import { IconHelp } from '@/components/Icons';
+import { CProps } from '@/components/props';
+import Loader from '@/components/ui/Loader';
 import TextURL from '@/components/ui/TextURL';
 import Tooltip, { PlacesType } from '@/components/ui/Tooltip';
 import { HelpTopic } from '@/models/miscellaneous';
 import { usePreferencesStore } from '@/stores/preferences';
 
-import { IconHelp } from '../Icons';
-import { CProps } from '../props';
-import Loader from '../ui/Loader';
-
 const TopicPage = React.lazy(() => import('@/pages/ManualsPage/TopicPage'));
 
 interface BadgeHelpProps extends CProps.Styling {

rsconcept/frontend/src/components/info/BadgeLocation.tsx

@@ -1,7 +1,6 @@
+import { LocationIcon } from '@/components/DomainIcons';
 import { globals } from '@/utils/constants';
 
-import { LocationIcon } from '../DomainIcons';
-
 interface BadgeLocationProps {
   /** Location to display. */
   location: string;

rsconcept/frontend/src/components/info/InfoConstituenta.tsx

@@ -1,12 +1,11 @@
 import clsx from 'clsx';
 
+import { IconChild } from '@/components/Icons';
+import { CProps } from '@/components/props';
 import { IConstituenta } from '@/models/rsform';
 import { isBasicConcept } from '@/models/rsformAPI';
 import { labelCstTypification } from '@/utils/labels';
 
-import { IconChild } from '../Icons';
-import { CProps } from '../props';
-
 interface InfoConstituentaProps extends CProps.Div {
   data: IConstituenta;
 }