Add application state hook (#1308)

* Add application state hook

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

* Add docs

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

src/components/common/branding/branding.tsx

@@ -4,12 +4,10 @@
  SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import equal from 'fast-deep-equal'
+import React, { useMemo } from 'react'
-import React from 'react'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../redux'
 import { ShowIf } from '../show-if/show-if'
 import './branding.scss'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export interface BrandingProps {
   inline?: boolean
@@ -17,24 +15,30 @@ export interface BrandingProps {
 }
 
 export const Branding: React.FC<BrandingProps> = ({ inline = false, delimiter = true }) => {
-  const branding = useSelector((state: ApplicationState) => state.config.branding, equal)
+  const branding = useApplicationState((state) => state.config.branding)
   const showBranding = !!branding.name || !!branding.logo
 
-  return (
+  const brandingDom = useMemo(() => {
-    <ShowIf condition={showBranding}>
+    if (branding.logo) {
-      <ShowIf condition={delimiter}>
+      return (
-        <strong className={`mx-1 ${inline ? 'inline-size' : 'regular-size'}`}>@</strong>
-      </ShowIf>
-      {branding.logo ? (
         <img
           src={branding.logo}
           alt={branding.name}
           title={branding.name}
           className={inline ? 'inline-size' : 'regular-size'}
         />
-      ) : (
+      )
-        branding.name
+    } else {
-      )}
+      return branding.name
+    }
+  }, [branding.logo, branding.name, inline])
+
+  return (
+    <ShowIf condition={showBranding}>
+      <ShowIf condition={delimiter}>
+        <strong className={`mx-1 ${inline ? 'inline-size' : 'regular-size'}`}>@</strong>
+      </ShowIf>
+      {brandingDom}
     </ShowIf>
   )
 }

src/components/common/motd-banner/motd-banner.tsx

@@ -4,17 +4,15 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import equal from 'fast-deep-equal'
 import React, { useCallback } from 'react'
 import { Alert, Button } from 'react-bootstrap'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../redux'
 import { setBanner } from '../../../redux/banner/methods'
 import { ForkAwesomeIcon } from '../fork-awesome/fork-awesome-icon'
 import { BANNER_LOCAL_STORAGE_KEY } from '../../application-loader/initializers/fetch-and-set-banner'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const MotdBanner: React.FC = () => {
-  const bannerState = useSelector((state: ApplicationState) => state.banner, equal)
+  const bannerState = useApplicationState((state) => state.banner)
 
   const dismissBanner = useCallback(() => {
     if (bannerState.lastModified) {

src/components/document-read-only-page/document-read-only-page.tsx

@@ -6,12 +6,10 @@
 
 import React, { useCallback } from 'react'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { useParams } from 'react-router'
 import { useApplyDarkMode } from '../../hooks/common/use-apply-dark-mode'
 import { useDocumentTitleWithNoteTitle } from '../../hooks/common/use-document-title-with-note-title'
 import { useNoteMarkdownContent } from '../../hooks/common/use-note-markdown-content'
-import { ApplicationState } from '../../redux'
 import { setNoteFrontmatter, updateNoteTitleByFirstHeading } from '../../redux/note-details/methods'
 import { MotdBanner } from '../common/motd-banner/motd-banner'
 import { ShowIf } from '../common/show-if/show-if'
@@ -23,6 +21,7 @@ import { DocumentInfobar } from './document-infobar'
 import { ErrorWhileLoadingNoteAlert } from './ErrorWhileLoadingNoteAlert'
 import { LoadingNoteAlert } from './LoadingNoteAlert'
 import { RendererType } from '../render-page/rendering-message'
+import { useApplicationState } from '../../hooks/common/use-application-state'
 
 export const DocumentReadOnlyPage: React.FC = () => {
   useTranslation()
@@ -35,7 +34,7 @@ export const DocumentReadOnlyPage: React.FC = () => {
   const onFrontmatterChange = useCallback(setNoteFrontmatter, [])
   const [error, loading] = useLoadNoteFromServer()
   const markdownContent = useNoteMarkdownContent()
-  const noteDetails = useSelector((state: ApplicationState) => state.noteDetails)
+  const noteDetails = useApplicationState((state) => state.noteDetails)
 
   return (
     <div className={'d-flex flex-column mvh-100 bg-light'}>

src/components/editor-page/app-bar/app-bar.tsx

@@ -5,10 +5,7 @@
  */
 
 import React from 'react'
-import equal from 'fast-deep-equal'
 import { Nav, Navbar } from 'react-bootstrap'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../redux'
 import { ShowIf } from '../../common/show-if/show-if'
 import { SignInButton } from '../../landing-layout/navigation/sign-in-button'
 import { UserDropdown } from '../../landing-layout/navigation/user-dropdown'
@@ -21,6 +18,7 @@ import { NoteType } from '../note-frontmatter/note-frontmatter'
 import { SlideModeButton } from './slide-mode-button'
 import { ReadOnlyModeButton } from './read-only-mode-button'
 import { NewNoteButton } from './new-note-button'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export enum AppBarMode {
   BASIC,
@@ -32,8 +30,8 @@ export interface AppBarProps {
 }
 
 export const AppBar: React.FC<AppBarProps> = ({ mode }) => {
-  const userExists = useSelector((state: ApplicationState) => !!state.user)
+  const userExists = useApplicationState((state) => !!state.user)
-  const noteFrontmatter = useSelector((state: ApplicationState) => state.noteDetails.frontmatter, equal)
+  const noteFrontmatter = useApplicationState((state) => state.noteDetails.frontmatter)
 
   return (
     <Navbar bg={'light'}>

src/components/editor-page/app-bar/editor-view-mode.tsx

@@ -7,10 +7,9 @@
 import React from 'react'
 import { ToggleButton, ToggleButtonGroup } from 'react-bootstrap'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../redux'
 import { setEditorMode } from '../../../redux/editor/methods'
 import { ForkAwesomeIcon } from '../../common/fork-awesome/fork-awesome-icon'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export enum EditorMode {
   PREVIEW = 'view',
@@ -20,7 +19,8 @@ export enum EditorMode {
 
 export const EditorViewMode: React.FC = () => {
   const { t } = useTranslation()
-  const editorMode = useSelector((state: ApplicationState) => state.editorConfig.editorMode)
+  const editorMode = useApplicationState((state) => state.editorConfig.editorMode)
+
   return (
     <ToggleButtonGroup
       type='radio'

src/components/editor-page/app-bar/sync-scroll-buttons/sync-scroll-buttons.tsx

@@ -7,12 +7,11 @@
 import React from 'react'
 import { ToggleButton, ToggleButtonGroup } from 'react-bootstrap'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../../redux'
 import { setEditorSyncScroll } from '../../../../redux/editor/methods'
 import { ReactComponent as DisabledScrollIcon } from './disabledScroll.svg'
 import { ReactComponent as EnabledScrollIcon } from './enabledScroll.svg'
 import './sync-scroll-buttons.scss'
+import { useApplicationState } from '../../../../hooks/common/use-application-state'
 
 enum SyncScrollState {
   SYNCED,
@@ -20,7 +19,7 @@ enum SyncScrollState {
 }
 
 export const SyncScrollButtons: React.FC = () => {
-  const syncScrollEnabled = useSelector((state: ApplicationState) => state.editorConfig.syncScroll)
+  const syncScrollEnabled = useApplicationState((state) => state.editorConfig.syncScroll)
     ? SyncScrollState.SYNCED
     : SyncScrollState.UNSYNCED
   const { t } = useTranslation()

src/components/editor-page/document-bar/share/share-modal.tsx

@@ -4,19 +4,17 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import equal from 'fast-deep-equal'
 import React from 'react'
 import { Modal } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { useParams } from 'react-router-dom'
 import { useFrontendBaseUrl } from '../../../../hooks/common/use-frontend-base-url'
-import { ApplicationState } from '../../../../redux'
 import { CopyableField } from '../../../common/copyable/copyable-field/copyable-field'
 import { CommonModal } from '../../../common/modals/common-modal'
 import { ShowIf } from '../../../common/show-if/show-if'
 import { EditorPagePathParams } from '../../editor-page'
 import { NoteType } from '../../note-frontmatter/note-frontmatter'
+import { useApplicationState } from '../../../../hooks/common/use-application-state'
 
 export interface ShareModalProps {
   show: boolean
@@ -25,8 +23,8 @@ export interface ShareModalProps {
 
 export const ShareModal: React.FC<ShareModalProps> = ({ show, onHide }) => {
   useTranslation()
-  const noteFrontmatter = useSelector((state: ApplicationState) => state.noteDetails.frontmatter, equal)
+  const noteFrontmatter = useApplicationState((state) => state.noteDetails.frontmatter)
-  const editorMode = useSelector((state: ApplicationState) => state.editorConfig.editorMode)
+  const editorMode = useApplicationState((state) => state.editorConfig.editorMode)
   const baseUrl = useFrontendBaseUrl()
   const { id } = useParams<EditorPagePathParams>()
 

src/components/editor-page/editor-page.tsx

@@ -6,11 +6,9 @@
 
 import React, { useCallback, useMemo, useRef, useState } from 'react'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { useApplyDarkMode } from '../../hooks/common/use-apply-dark-mode'
 import { useDocumentTitleWithNoteTitle } from '../../hooks/common/use-document-title-with-note-title'
 import { useNoteMarkdownContent } from '../../hooks/common/use-note-markdown-content'
-import { ApplicationState } from '../../redux'
 import {
   SetCheckboxInMarkdownContent,
   setNoteFrontmatter,
@@ -36,6 +34,7 @@ import { UiNotifications } from '../notifications/ui-notifications'
 import { useNotificationTest } from './use-notification-test'
 import { IframeCommunicatorContextProvider } from './render-context/iframe-communicator-context-provider'
 import { useUpdateLocalHistoryEntry } from './hooks/useUpdateLocalHistoryEntry'
+import { useApplicationState } from '../../hooks/common/use-application-state'
 
 export interface EditorPagePathParams {
   id: string
@@ -51,8 +50,8 @@ export const EditorPage: React.FC = () => {
   const markdownContent = useNoteMarkdownContent()
   const scrollSource = useRef<ScrollSource>(ScrollSource.EDITOR)
 
-  const editorMode: EditorMode = useSelector((state: ApplicationState) => state.editorConfig.editorMode)
+  const editorMode: EditorMode = useApplicationState((state) => state.editorConfig.editorMode)
-  const editorSyncScroll: boolean = useSelector((state: ApplicationState) => state.editorConfig.syncScroll)
+  const editorSyncScroll: boolean = useApplicationState((state) => state.editorConfig.syncScroll)
 
   const [scrollState, setScrollState] = useState<DualScrollState>(() => ({
     editorScrollState: { firstLineInView: 1, scrolledPercentage: 0 },

src/components/editor-page/editor-pane/editor-pane.tsx

@@ -27,12 +27,9 @@ import 'codemirror/keymap/emacs'
 import 'codemirror/keymap/sublime'
 import 'codemirror/keymap/vim'
 import 'codemirror/mode/gfm/gfm'
-import equal from 'fast-deep-equal'
 import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 import { Controlled as ControlledCodeMirror } from 'react-codemirror2'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../redux'
 import { MaxLengthWarningModal } from '../editor-modals/max-length-warning-modal'
 import { ScrollProps, ScrollState } from '../synced-scroll/scroll-props'
 import { allHinters, findWordAtCursor } from './autocompletion'
@@ -42,6 +39,7 @@ import { createStatusInfo, defaultState, StatusBar, StatusBarInfo } from './stat
 import { ToolBar } from './tool-bar/tool-bar'
 import { handleUpload } from './upload-handler'
 import { handleFilePaste, handleTablePaste, PasteEvent } from './tool-bar/utils/pasteHandlers'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export interface EditorPaneProps {
   onContentChange: (content: string) => void
@@ -81,14 +79,14 @@ export const EditorPane: React.FC<EditorPaneProps & ScrollProps> = ({
   onMakeScrollSource
 }) => {
   const { t } = useTranslation()
-  const maxLength = useSelector((state: ApplicationState) => state.config.maxDocumentLength)
+  const maxLength = useApplicationState((state) => state.config.maxDocumentLength)
-  const smartPasteEnabled = useSelector((state: ApplicationState) => state.editorConfig.smartPaste)
+  const smartPasteEnabled = useApplicationState((state) => state.editorConfig.smartPaste)
   const [showMaxLengthWarning, setShowMaxLengthWarning] = useState(false)
   const maxLengthWarningAlreadyShown = useRef(false)
   const [editor, setEditor] = useState<Editor>()
   const [statusBarInfo, setStatusBarInfo] = useState<StatusBarInfo>(defaultState)
-  const editorPreferences = useSelector((state: ApplicationState) => state.editorConfig.preferences, equal)
+  const editorPreferences = useApplicationState((state) => state.editorConfig.preferences)
-  const ligaturesEnabled = useSelector((state: ApplicationState) => state.editorConfig.ligatures, equal)
+  const ligaturesEnabled = useApplicationState((state) => state.editorConfig.ligatures)
 
   const lastScrollPosition = useRef<number>()
   const [editorScroll, setEditorScroll] = useState<ScrollInfo>()

src/components/editor-page/editor-pane/tool-bar/editor-preferences/editor-preference-boolean-property.tsx

@@ -5,24 +5,19 @@
  */
 
 import { EditorConfiguration } from 'codemirror'
-import equal from 'fast-deep-equal'
 import React, { ChangeEvent, useCallback } from 'react'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../../../redux'
 import { mergeEditorPreferences } from '../../../../../redux/editor/methods'
 import { EditorPreferenceInput, EditorPreferenceInputType } from './editor-preference-input'
 import { EditorPreferenceProperty } from './editor-preference-property'
+import { useApplicationState } from '../../../../../hooks/common/use-application-state'
 
 export interface EditorPreferenceBooleanProps {
   property: EditorPreferenceProperty
 }
 
 export const EditorPreferenceBooleanProperty: React.FC<EditorPreferenceBooleanProps> = ({ property }) => {
-  const preference = useSelector(
+  const preference = useApplicationState((state) => state.editorConfig.preferences[property]?.toString() ?? '')
-    (state: ApplicationState) => state.editorConfig.preferences[property]?.toString() || '',
-    equal
-  )
 
   const { t } = useTranslation()
   const selectItem = useCallback(

src/components/editor-page/editor-pane/tool-bar/editor-preferences/editor-preference-ligatures-select.tsx

@@ -5,13 +5,12 @@
  */
 import React, { ChangeEvent, useCallback } from 'react'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../../../redux'
 import { setEditorLigatures } from '../../../../../redux/editor/methods'
 import { EditorPreferenceInput, EditorPreferenceInputType } from './editor-preference-input'
+import { useApplicationState } from '../../../../../hooks/common/use-application-state'
 
 export const EditorPreferenceLigaturesSelect: React.FC = () => {
-  const ligaturesEnabled = useSelector((state: ApplicationState) => Boolean(state.editorConfig.ligatures).toString())
+  const ligaturesEnabled = useApplicationState((state) => Boolean(state.editorConfig.ligatures).toString())
   const saveLigatures = useCallback((event: ChangeEvent<HTMLSelectElement>) => {
     const ligaturesActivated: boolean = event.target.value === 'true'
     setEditorLigatures(ligaturesActivated)

src/components/editor-page/editor-pane/tool-bar/editor-preferences/editor-preference-number-property.tsx

@@ -5,23 +5,18 @@
  */
 
 import { EditorConfiguration } from 'codemirror'
-import equal from 'fast-deep-equal'
 import React, { ChangeEvent, useCallback } from 'react'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../../../redux'
 import { mergeEditorPreferences } from '../../../../../redux/editor/methods'
 import { EditorPreferenceInput, EditorPreferenceInputType } from './editor-preference-input'
 import { EditorPreferenceProperty } from './editor-preference-property'
+import { useApplicationState } from '../../../../../hooks/common/use-application-state'
 
 export interface EditorPreferenceNumberProps {
   property: EditorPreferenceProperty
 }
 
 export const EditorPreferenceNumberProperty: React.FC<EditorPreferenceNumberProps> = ({ property }) => {
-  const preference = useSelector(
+  const preference = useApplicationState((state) => state.editorConfig.preferences[property]?.toString() ?? '')
-    (state: ApplicationState) => state.editorConfig.preferences[property]?.toString() || '',
-    equal
-  )
 
   const selectItem = useCallback(
     (event: ChangeEvent<HTMLSelectElement>) => {

src/components/editor-page/editor-pane/tool-bar/editor-preferences/editor-preference-select-property.tsx

@@ -5,14 +5,12 @@
  */
 
 import { EditorConfiguration } from 'codemirror'
-import equal from 'fast-deep-equal'
 import React, { ChangeEvent, useCallback } from 'react'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../../../redux'
 import { mergeEditorPreferences } from '../../../../../redux/editor/methods'
 import { EditorPreferenceInput, EditorPreferenceInputType } from './editor-preference-input'
 import { EditorPreferenceProperty } from './editor-preference-property'
+import { useApplicationState } from '../../../../../hooks/common/use-application-state'
 
 export interface EditorPreferenceSelectPropertyProps {
   property: EditorPreferenceProperty
@@ -23,10 +21,7 @@ export const EditorPreferenceSelectProperty: React.FC<EditorPreferenceSelectProp
   property,
   selections
 }) => {
-  const preference = useSelector(
+  const preference = useApplicationState((state) => state.editorConfig.preferences[property]?.toString() ?? '')
-    (state: ApplicationState) => state.editorConfig.preferences[property]?.toString() || '',
-    equal
-  )
 
   const { t } = useTranslation()
 

src/components/editor-page/editor-pane/tool-bar/editor-preferences/editor-preference-smart-paste-select.tsx

@@ -5,13 +5,12 @@
  */
 import React, { ChangeEvent, useCallback } from 'react'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from '../../../../../hooks/common/use-application-state'
-import { ApplicationState } from '../../../../../redux'
 import { setEditorSmartPaste } from '../../../../../redux/editor/methods'
 import { EditorPreferenceInput, EditorPreferenceInputType } from './editor-preference-input'
 
 export const EditorPreferenceSmartPasteSelect: React.FC = () => {
-  const smartPasteEnabled = useSelector((state: ApplicationState) => Boolean(state.editorConfig.smartPaste).toString())
+  const smartPasteEnabled = useApplicationState((state) => Boolean(state.editorConfig.smartPaste).toString())
   const saveSmartPaste = useCallback((event: ChangeEvent<HTMLSelectElement>) => {
     const smartPasteActivated: boolean = event.target.value === 'true'
     setEditorSmartPaste(smartPasteActivated)

src/components/editor-page/editor-pane/tool-bar/editor-preferences/editor-preferences.tsx

@@ -4,12 +4,9 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import equal from 'fast-deep-equal'
 import React, { Fragment, useState } from 'react'
 import { Button, Form, ListGroup } from 'react-bootstrap'
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../../../redux'
 import { ForkAwesomeIcon } from '../../../../common/fork-awesome/fork-awesome-icon'
 import { CommonModal } from '../../../../common/modals/common-modal'
 import { ShowIf } from '../../../../common/show-if/show-if'
@@ -20,14 +17,12 @@ import { EditorPreferenceNumberProperty } from './editor-preference-number-prope
 import { EditorPreferenceProperty } from './editor-preference-property'
 import { EditorPreferenceSelectProperty } from './editor-preference-select-property'
 import { EditorPreferenceSmartPasteSelect } from './editor-preference-smart-paste-select'
+import { useApplicationState } from '../../../../../hooks/common/use-application-state'
 
 export const EditorPreferences: React.FC = () => {
   const { t } = useTranslation()
   const [showModal, setShowModal] = useState(false)
-  const indentWithTabs = useSelector(
+  const indentWithTabs = useApplicationState((state) => state.editorConfig.preferences.indentWithTabs ?? false)
-    (state: ApplicationState) => state.editorConfig.preferences.indentWithTabs ?? false,
-    equal
-  )
 
   return (
     <Fragment>

src/components/editor-page/hooks/useUpdateLocalHistoryEntry.ts

@@ -6,18 +6,18 @@
 
 import equal from 'fast-deep-equal'
 import { useEffect, useRef } from 'react'
-import { useSelector } from 'react-redux'
+import { store } from '../../../redux'
-import { ApplicationState, store } from '../../../redux'
 import { useParams } from 'react-router-dom'
 import { EditorPagePathParams } from '../editor-page'
 import { HistoryEntry, HistoryEntryOrigin } from '../../../redux/history/types'
 import { updateLocalHistoryEntry } from '../../../redux/history/methods'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const useUpdateLocalHistoryEntry = (updateReady: boolean): void => {
   const { id } = useParams<EditorPagePathParams>()
-  const userExists = useSelector((state: ApplicationState) => !!state.user)
+  const userExists = useApplicationState((state) => !!state.user)
-  const currentNoteTitle = useSelector((state: ApplicationState) => state.noteDetails.noteTitle)
+  const currentNoteTitle = useApplicationState((state) => state.noteDetails.noteTitle)
-  const currentNoteTags = useSelector((state: ApplicationState) => state.noteDetails.frontmatter.tags)
+  const currentNoteTags = useApplicationState((state) => state.noteDetails.frontmatter.tags)
 
   const lastNoteTitle = useRef('')
   const lastNoteTags = useRef<string[]>([])

src/components/editor-page/renderer-pane/render-iframe.tsx

@@ -5,9 +5,8 @@
  */
 import equal from 'fast-deep-equal'
 import React, { Fragment, useCallback, useEffect, useRef, useState } from 'react'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 import { useIsDarkModeActivated } from '../../../hooks/common/use-is-dark-mode-activated'
-import { ApplicationState } from '../../../redux'
 import { isTestMode } from '../../../utils/test-modes'
 import { RendererProps } from '../../render-page/markdown-document'
 import { ImageDetails, RendererType } from '../../render-page/rendering-message'
@@ -42,7 +41,7 @@ export const RenderIframe: React.FC<RenderIframeProps> = ({
   const [lightboxDetails, setLightboxDetails] = useState<ImageDetails | undefined>(undefined)
 
   const frameReference = useRef<HTMLIFrameElement>(null)
-  const rendererOrigin = useSelector((state: ApplicationState) => state.config.iframeCommunication.rendererOrigin)
+  const rendererOrigin = useApplicationState((state) => state.config.iframeCommunication.rendererOrigin)
   const renderPageUrl = `${rendererOrigin}render`
   const resetRendererReady = useCallback(() => setRendererReady(false), [])
   const iframeCommunicator = useContextOrStandaloneIframeCommunicator()

src/components/editor-page/renderer-pane/yaml-array-deprecation-alert.tsx

@@ -7,17 +7,14 @@
 import React from 'react'
 import { Alert } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import links from '../../../links.json'
-import { ApplicationState } from '../../../redux'
 import { TranslatedExternalLink } from '../../common/links/translated-external-link'
 import { ShowIf } from '../../common/show-if/show-if'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const YamlArrayDeprecationAlert: React.FC = () => {
   useTranslation()
-  const yamlDeprecatedTags = useSelector(
+  const yamlDeprecatedTags = useApplicationState((state) => state.noteDetails.frontmatter.deprecatedTagsSyntax)
-    (state: ApplicationState) => state.noteDetails.frontmatter.deprecatedTagsSyntax
-  )
 
   return (
     <ShowIf condition={yamlDeprecatedTags}>

src/components/editor-page/sidebar/pin-note-sidebar-entry.tsx

@@ -10,15 +10,14 @@ import { SidebarButton } from './sidebar-button'
 import { SpecificSidebarEntryProps } from './types'
 import { useParams } from 'react-router-dom'
 import { EditorPagePathParams } from '../editor-page'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../redux'
 import { toggleHistoryEntryPinning } from '../../../redux/history/methods'
 import { showErrorNotification } from '../../../redux/ui-notifications/methods'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const PinNoteSidebarEntry: React.FC<SpecificSidebarEntryProps> = ({ className, hide }) => {
   const { t } = useTranslation()
   const { id } = useParams<EditorPagePathParams>()
-  const history = useSelector((state: ApplicationState) => state.history)
+  const history = useApplicationState((state) => state.history)
 
   const isPinned = useMemo(() => {
     const entry = history.find((entry) => entry.identifier === id)

src/components/history-page/entry-menu/entry-menu.tsx

@@ -13,8 +13,7 @@ import { DeleteNoteItem } from './delete-note-item'
 import './entry-menu.scss'
 import { RemoveNoteEntryItem } from './remove-note-entry-item'
 import { HistoryEntryOrigin } from '../../../redux/history/types'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
-import { ApplicationState } from '../../../redux'
 
 export interface EntryMenuProps {
   id: string
@@ -29,7 +28,7 @@ export interface EntryMenuProps {
 export const EntryMenu: React.FC<EntryMenuProps> = ({ id, title, origin, isDark, onRemove, onDelete, className }) => {
   useTranslation()
 
-  const userExists = useSelector((state: ApplicationState) => !!state.user)
+  const userExists = useApplicationState((state) => !!state.user)
 
   return (
     <Dropdown className={`d-inline-flex ${className || ''}`}>

src/components/history-page/history-page.tsx

@@ -7,19 +7,18 @@
 import React, { Fragment, useEffect, useMemo, useState } from 'react'
 import { Row } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../redux'
 import { HistoryContent } from './history-content/history-content'
 import { HistoryToolbar, HistoryToolbarState, initToolbarState } from './history-toolbar/history-toolbar'
 import { sortAndFilterEntries } from './utils'
 import { refreshHistoryState } from '../../redux/history/methods'
 import { HistoryEntry } from '../../redux/history/types'
 import { showErrorNotification } from '../../redux/ui-notifications/methods'
+import { useApplicationState } from '../../hooks/common/use-application-state'
 
 export const HistoryPage: React.FC = () => {
   const { t } = useTranslation()
 
-  const allEntries = useSelector((state: ApplicationState) => state.history)
+  const allEntries = useApplicationState((state) => state.history)
   const [toolbarState, setToolbarState] = useState<HistoryToolbarState>(initToolbarState)
 
   const entriesToShow = useMemo<HistoryEntry[]>(

src/components/history-page/history-toolbar/history-toolbar.tsx

@@ -9,9 +9,7 @@ import React, { ChangeEvent, useCallback, useEffect, useMemo, useRef, useState }
 import { Button, Form, FormControl, InputGroup, ToggleButton, ToggleButtonGroup } from 'react-bootstrap'
 import { Typeahead } from 'react-bootstrap-typeahead'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { useQueryState } from 'react-router-use-location-state'
-import { ApplicationState } from '../../../redux'
 import { ForkAwesomeIcon } from '../../common/fork-awesome/fork-awesome-icon'
 import { ShowIf } from '../../common/show-if/show-if'
 import { SortButton, SortModeEnum } from '../sort-button/sort-button'
@@ -22,6 +20,7 @@ import './typeahead-hacks.scss'
 import { HistoryEntryOrigin } from '../../../redux/history/types'
 import { importHistoryEntries, refreshHistoryState, setHistoryEntries } from '../../../redux/history/methods'
 import { showErrorNotification } from '../../../redux/ui-notifications/methods'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export type HistoryToolbarChange = (newState: HistoryToolbarState) => void
 
@@ -61,8 +60,8 @@ export const initToolbarState: HistoryToolbarState = {
 
 export const HistoryToolbar: React.FC<HistoryToolbarProps> = ({ onSettingsChange }) => {
   const { t } = useTranslation()
-  const historyEntries = useSelector((state: ApplicationState) => state.history)
+  const historyEntries = useApplicationState((state) => state.history)
-  const userExists = useSelector((state: ApplicationState) => !!state.user)
+  const userExists = useApplicationState((state) => !!state.user)
 
   const tags = useMemo<string[]>(() => {
     const allTags = historyEntries.map((entry) => entry.tags).flat()

src/components/history-page/history-toolbar/import-history-button.tsx

@@ -16,14 +16,13 @@ import {
   mergeHistoryEntries,
   refreshHistoryState
 } from '../../../redux/history/methods'
-import { ApplicationState } from '../../../redux'
-import { useSelector } from 'react-redux'
 import { showErrorNotification } from '../../../redux/ui-notifications/methods'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const ImportHistoryButton: React.FC = () => {
   const { t } = useTranslation()
-  const userExists = useSelector((state: ApplicationState) => !!state.user)
+  const userExists = useApplicationState((state) => !!state.user)
-  const historyState = useSelector((state: ApplicationState) => state.history)
+  const historyState = useApplicationState((state) => state.history)
   const uploadInput = useRef<HTMLInputElement>(null)
   const [show, setShow] = useState(false)
   const [fileName, setFilename] = useState('')

src/components/intro-page/cover-buttons/cover-buttons.tsx

@@ -7,17 +7,16 @@
 import React from 'react'
 import { Button } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { Link } from 'react-router-dom'
-import { ApplicationState } from '../../../redux'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 import { ShowIf } from '../../common/show-if/show-if'
 import { SignInButton } from '../../landing-layout/navigation/sign-in-button'
 import './cover-buttons.scss'
 
 export const CoverButtons: React.FC = () => {
   useTranslation()
-  const userExists = useSelector((state: ApplicationState) => !!state.user)
+  const userExists = useApplicationState((state) => !!state.user)
-  const anyAuthProviderActivated = useSelector((state: ApplicationState) =>
+  const anyAuthProviderActivated = useApplicationState((state) =>
     Object.values(state.config.authProviders).includes(true)
   )
 

src/components/landing-layout/footer/powered-by-links.tsx

@@ -6,21 +6,18 @@
 
 import React, { Fragment } from 'react'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import links from '../../../links.json'
-import { ApplicationState } from '../../../redux'
 import { ExternalLink } from '../../common/links/external-link'
 import { TranslatedExternalLink } from '../../common/links/translated-external-link'
 import { TranslatedInternalLink } from '../../common/links/translated-internal-link'
 import { VersionInfoLink } from './version-info/version-info-link'
-import equal from 'fast-deep-equal'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const PoweredByLinks: React.FC = () => {
   useTranslation()
 
-  const specialUrls: [string, string][] = useSelector(
+  const specialUrls: [string, string][] = useApplicationState((state) =>
-    (state: ApplicationState) => Object.entries(state.config.specialUrls) as [string, string][],
+    Object.entries(state.config.specialUrls).map(([i18nkey, url]) => [i18nkey, String(url)])
-    equal
   )
 
   return (

src/components/landing-layout/footer/version-info/version-info-modal.tsx

@@ -10,13 +10,11 @@ import { Modal, Row } from 'react-bootstrap'
 import { VersionInfoModalColumn } from './version-info-modal-column'
 import frontendVersion from '../../../../version.json'
 import links from '../../../../links.json'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../../redux'
-import equal from 'fast-deep-equal'
 import { BackendVersion } from '../../../../api/config/types'
+import { useApplicationState } from '../../../../hooks/common/use-application-state'
 
 export const VersionInfoModal: React.FC<CommonModalProps> = ({ onHide, show }) => {
-  const serverVersion: BackendVersion = useSelector((state: ApplicationState) => state.config.version, equal)
+  const serverVersion: BackendVersion = useApplicationState((state) => state.config.version)
   const backendVersion = useMemo(() => {
     const version = `${serverVersion.major}.${serverVersion.minor}.${serverVersion.patch}`
 

src/components/landing-layout/navigation/header-bar/header-bar.tsx

@@ -7,8 +7,7 @@
 import React, { Fragment } from 'react'
 import { Navbar } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from '../../../../hooks/common/use-application-state'
-import { ApplicationState } from '../../../../redux'
 import { HeaderNavLink } from '../header-nav-link'
 import { NewGuestNoteButton } from '../new-guest-note-button'
 import { NewUserNoteButton } from '../new-user-note-button'
@@ -18,7 +17,7 @@ import './header-bar.scss'
 
 const HeaderBar: React.FC = () => {
   useTranslation()
-  const userExists = useSelector((state: ApplicationState) => !!state.user)
+  const userExists = useApplicationState((state) => !!state.user)
 
   return (
     <Navbar className='justify-content-between'>

src/components/landing-layout/navigation/sign-in-button.tsx

@@ -4,23 +4,21 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import equal from 'fast-deep-equal'
 import React, { useMemo } from 'react'
 import { Button } from 'react-bootstrap'
 import { ButtonProps } from 'react-bootstrap/Button'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { LinkContainer } from 'react-router-bootstrap'
-import { ApplicationState } from '../../../redux'
 import { ShowIf } from '../../common/show-if/show-if'
 import { getApiUrl } from '../../../api/utils'
 import { INTERACTIVE_LOGIN_METHODS } from '../../../api/auth'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export type SignInButtonProps = Omit<ButtonProps, 'href'>
 
 export const SignInButton: React.FC<SignInButtonProps> = ({ variant, ...props }) => {
   const { t } = useTranslation()
-  const authProviders = useSelector((state: ApplicationState) => state.config.authProviders, equal)
+  const authProviders = useApplicationState((state) => state.config.authProviders)
   const authEnabled = useMemo(() => Object.values(authProviders).includes(true), [authProviders])
 
   const loginLink = useMemo(() => {

src/components/landing-layout/navigation/user-dropdown.tsx

@@ -4,20 +4,18 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import equal from 'fast-deep-equal'
 import React from 'react'
 import { Dropdown } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { LinkContainer } from 'react-router-bootstrap'
-import { ApplicationState } from '../../../redux'
 import { clearUser } from '../../../redux/user/methods'
 import { ForkAwesomeIcon } from '../../common/fork-awesome/fork-awesome-icon'
 import { UserAvatar } from '../../common/user-avatar/user-avatar'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const UserDropdown: React.FC = () => {
   useTranslation()
-  const user = useSelector((state: ApplicationState) => state.user, equal)
+  const user = useApplicationState((state) => state.user)
 
   if (!user) {
     return null

src/components/login-page/auth/via-internal.tsx

@@ -7,19 +7,18 @@
 import React, { FormEvent, useCallback, useState } from 'react'
 import { Alert, Button, Card, Form } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { Link } from 'react-router-dom'
 import { doInternalLogin } from '../../../api/auth'
-import { ApplicationState } from '../../../redux'
 import { ShowIf } from '../../common/show-if/show-if'
 import { fetchAndSetUser } from './utils'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const ViaInternal: React.FC = () => {
   const { t } = useTranslation()
   const [username, setUsername] = useState('')
   const [password, setPassword] = useState('')
   const [error, setError] = useState(false)
-  const allowRegister = useSelector((state: ApplicationState) => state.config.allowRegister)
+  const allowRegister = useApplicationState((state) => state.config.allowRegister)
 
   const onLoginSubmit = useCallback(
     (event: FormEvent) => {

src/components/login-page/auth/via-ldap.tsx

@@ -8,14 +8,13 @@ import React, { FormEvent, useCallback, useState } from 'react'
 import { Alert, Button, Card, Form } from 'react-bootstrap'
 
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { doLdapLogin } from '../../../api/auth'
-import { ApplicationState } from '../../../redux'
 import { fetchAndSetUser } from './utils'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const ViaLdap: React.FC = () => {
   const { t } = useTranslation()
-  const ldapCustomName = useSelector((state: ApplicationState) => state.config.customAuthNames.ldap)
+  const ldapCustomName = useApplicationState((state) => state.config.customAuthNames.ldap)
 
   const [username, setUsername] = useState('')
   const [password, setPassword] = useState('')

src/components/login-page/auth/via-one-click.tsx

@@ -5,8 +5,7 @@
  */
 
 import React from 'react'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
-import { ApplicationState } from '../../../redux'
 import { IconName } from '../../common/fork-awesome/types'
 import { SocialLinkButton } from './social-link-button/social-link-button'
 
@@ -108,7 +107,7 @@ export interface ViaOneClickProps {
 }
 
 export const ViaOneClick: React.FC<ViaOneClickProps> = ({ oneClickType, optionalName }) => {
-  const backendUrl = useSelector((state: ApplicationState) => state.apiUrl.apiUrl)
+  const backendUrl = useApplicationState((state) => state.apiUrl.apiUrl)
   const { name, icon, className, url } = getMetadata(backendUrl, oneClickType)
   const text = optionalName || name
 

src/components/login-page/login-page.tsx

@@ -4,25 +4,23 @@
  SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import equal from 'fast-deep-equal'
 import React, { Fragment } from 'react'
 import { Card, Col, Row } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { Redirect } from 'react-router'
-import { ApplicationState } from '../../redux'
 import { ShowIf } from '../common/show-if/show-if'
 import { ViaInternal } from './auth/via-internal'
 import { ViaLdap } from './auth/via-ldap'
 import { OneClickType, ViaOneClick } from './auth/via-one-click'
 import { ViaOpenId } from './auth/via-openid'
+import { useApplicationState } from '../../hooks/common/use-application-state'
 
 export const LoginPage: React.FC = () => {
   useTranslation()
-  const authProviders = useSelector((state: ApplicationState) => state.config.authProviders, equal)
+  const authProviders = useApplicationState((state) => state.config.authProviders)
-  const customSamlAuthName = useSelector((state: ApplicationState) => state.config.customAuthNames.saml)
+  const customSamlAuthName = useApplicationState((state) => state.config.customAuthNames.saml)
-  const customOauthAuthName = useSelector((state: ApplicationState) => state.config.customAuthNames.oauth2)
+  const customOauthAuthName = useApplicationState((state) => state.config.customAuthNames.oauth2)
-  const userLoggedIn = useSelector((state: ApplicationState) => !!state.user)
+  const userLoggedIn = useApplicationState((state) => !!state.user)
 
   const oneClickProviders = [
     authProviders.dropbox,

src/components/markdown-renderer/document-length-limit-reached-alert.tsx

@@ -7,15 +7,14 @@
 import React from 'react'
 import { Alert } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from '../../hooks/common/use-application-state'
-import { ApplicationState } from '../../redux'
 import { ShowIf } from '../common/show-if/show-if'
 import { SimpleAlertProps } from '../common/simple-alert/simple-alert-props'
 
 export const DocumentLengthLimitReachedAlert: React.FC<SimpleAlertProps> = ({ show }) => {
   useTranslation()
 
-  const maxLength = useSelector((state: ApplicationState) => state.config.maxDocumentLength)
+  const maxLength = useApplicationState((state) => state.config.maxDocumentLength)
 
   return (
     <ShowIf condition={show}>

src/components/markdown-renderer/hooks/use-trimmed-content.ts

@@ -4,12 +4,11 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../../redux'
 import { useMemo } from 'react'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const useTrimmedContent = (content: string): [trimmedContent: string, contentExceedsLimit: boolean] => {
-  const maxLength = useSelector((state: ApplicationState) => state.config.maxDocumentLength)
+  const maxLength = useApplicationState((state) => state.config.maxDocumentLength)
   const contentExceedsLimit = content.length > maxLength
 
   const trimmedContent = useMemo(

src/components/markdown-renderer/replace-components/image/proxy-image-frame.tsx

@@ -5,13 +5,12 @@
  */
 
 import React, { useEffect, useState } from 'react'
-import { useSelector } from 'react-redux'
 import { getProxiedUrl } from '../../../../api/media'
-import { ApplicationState } from '../../../../redux'
+import { useApplicationState } from '../../../../hooks/common/use-application-state'
 
 export const ProxyImageFrame: React.FC<React.ImgHTMLAttributes<HTMLImageElement>> = ({ src, title, alt, ...props }) => {
   const [imageUrl, setImageUrl] = useState('')
-  const imageProxyEnabled = useSelector((state: ApplicationState) => state.config.useImageProxy)
+  const imageProxyEnabled = useApplicationState((state) => state.config.useImageProxy)
 
   useEffect(() => {
     if (!imageProxyEnabled || !src) {

src/components/notifications/ui-notifications.tsx

@@ -7,12 +7,10 @@
 import React from 'react'
 import { UiNotificationToast } from './ui-notification-toast'
 import './notifications.scss'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from '../../hooks/common/use-application-state'
-import { ApplicationState } from '../../redux'
-import equal from 'fast-deep-equal'
 
 export const UiNotifications: React.FC = () => {
-  const notifications = useSelector((state: ApplicationState) => state.uiNotifications, equal)
+  const notifications = useApplicationState((state) => state.uiNotifications)
 
   return (
     <div className={'notifications-area'} aria-live='polite' aria-atomic='true'>

src/components/profile-page/profile-page.tsx

@@ -6,9 +6,8 @@
 
 import React, { Fragment } from 'react'
 import { Col, Row } from 'react-bootstrap'
-import { useSelector } from 'react-redux'
 import { Redirect } from 'react-router'
-import { ApplicationState } from '../../redux'
+import { useApplicationState } from '../../hooks/common/use-application-state'
 import { LoginProvider } from '../../redux/user/types'
 import { ShowIf } from '../common/show-if/show-if'
 import { ProfileAccessTokens } from './access-tokens/profile-access-tokens'
@@ -17,7 +16,7 @@ import { ProfileChangePassword } from './settings/profile-change-password'
 import { ProfileDisplayName } from './settings/profile-display-name'
 
 export const ProfilePage: React.FC = () => {
-  const userProvider = useSelector((state: ApplicationState) => state.user?.provider)
+  const userProvider = useApplicationState((state) => state.user?.provider)
 
   if (!userProvider) {
     return <Redirect to={'/login'} />

src/components/profile-page/settings/profile-display-name.tsx

@@ -7,15 +7,14 @@
 import React, { ChangeEvent, FormEvent, useEffect, useState } from 'react'
 import { Alert, Button, Card, Form } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { updateDisplayName } from '../../../api/me'
-import { ApplicationState } from '../../../redux'
 import { fetchAndSetUser } from '../../login-page/auth/utils'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const ProfileDisplayName: React.FC = () => {
   const regexInvalidDisplayName = /^\s*$/
   const { t } = useTranslation()
-  const userName = useSelector((state: ApplicationState) => state.user?.name)
+  const userName = useApplicationState((state) => state.user?.name)
   const [submittable, setSubmittable] = useState(false)
   const [error, setError] = useState(false)
   const [displayName, setDisplayName] = useState('')

src/components/register-page/register-page.tsx

@@ -7,10 +7,9 @@
 import React, { FormEvent, Fragment, useCallback, useEffect, useState } from 'react'
 import { Alert, Button, Card, Col, Form, Row } from 'react-bootstrap'
 import { Trans, useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
 import { Redirect } from 'react-router'
 import { doInternalRegister } from '../../api/auth'
-import { ApplicationState } from '../../redux'
+import { useApplicationState } from '../../hooks/common/use-application-state'
 import { TranslatedExternalLink } from '../common/links/translated-external-link'
 import { ShowIf } from '../common/show-if/show-if'
 import { fetchAndSetUser } from '../login-page/auth/utils'
@@ -23,9 +22,9 @@ export enum RegisterError {
 
 export const RegisterPage: React.FC = () => {
   const { t } = useTranslation()
-  const allowRegister = useSelector((state: ApplicationState) => state.config.allowRegister)
+  const allowRegister = useApplicationState((state) => state.config.allowRegister)
-  const specialUrls = useSelector((state: ApplicationState) => state.config.specialUrls)
+  const specialUrls = useApplicationState((state) => state.config.specialUrls)
-  const userExists = useSelector((state: ApplicationState) => !!state.user)
+  const userExists = useApplicationState((state) => !!state.user)
 
   const [username, setUsername] = useState('')
   const [password, setPassword] = useState('')

src/components/render-page/markdown-document.tsx

@@ -14,10 +14,9 @@ import { ScrollProps } from '../editor-page/synced-scroll/scroll-props'
 import { BasicMarkdownRenderer } from '../markdown-renderer/basic-markdown-renderer'
 import { ImageClickHandler } from '../markdown-renderer/replace-components/image/image-replacer'
 import './markdown-document.scss'
-import { useSelector } from 'react-redux'
-import { ApplicationState } from '../../redux'
 import { WidthBasedTableOfContents } from './width-based-table-of-contents'
 import { ShowIf } from '../common/show-if/show-if'
+import { useApplicationState } from '../../hooks/common/use-application-state'
 
 export interface RendererProps extends ScrollProps {
   onFirstHeadingChange?: (firstHeading: string | undefined) => void
@@ -60,7 +59,7 @@ export const MarkdownDocument: React.FC<MarkdownDocumentProps> = ({
 
   const [tocAst, setTocAst] = useState<TocAst>()
 
-  const useAlternativeBreaks = useSelector((state: ApplicationState) => state.noteDetails.frontmatter.breaks)
+  const useAlternativeBreaks = useApplicationState((state) => state.noteDetails.frontmatter.breaks)
 
   useEffect(() => {
     if (!onHeightChange) {

src/components/render-page/render-page.tsx

@@ -4,9 +4,8 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 import React, { useCallback, useEffect, useMemo, useState } from 'react'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from '../../hooks/common/use-application-state'
 import { useApplyDarkMode } from '../../hooks/common/use-apply-dark-mode'
-import { ApplicationState } from '../../redux'
 import { setDarkMode } from '../../redux/dark-mode/methods'
 import { setNoteFrontmatter } from '../../redux/note-details/methods'
 import { NoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatter'
@@ -24,7 +23,7 @@ export const RenderPage: React.FC = () => {
   const [scrollState, setScrollState] = useState<ScrollState>({ firstLineInView: 1, scrolledPercentage: 0 })
   const [baseConfiguration, setBaseConfiguration] = useState<BaseConfiguration | undefined>(undefined)
 
-  const editorOrigin = useSelector((state: ApplicationState) => state.config.iframeCommunication.editorOrigin)
+  const editorOrigin = useApplicationState((state) => state.config.iframeCommunication.editorOrigin)
 
   const iframeCommunicator = useMemo(() => {
     const newCommunicator = new IframeRendererToEditorCommunicator()

src/hooks/common/use-application-state.ts

@@ -0,0 +1,22 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { useSelector } from 'react-redux'
+import { ApplicationState } from '../../redux'
+import equal from 'fast-deep-equal'
+
+/**
+ * Accesses the global application state to retrieve information.
+ *
+ * @param selector A selector function that extracts the needed information from the state.
+ * @param checkForEquality An optional custom equality function. If not provided then {@link equal equal from fast-deep-equal} will be used.
+ */
+export const useApplicationState = <TSelected>(
+  selector: (state: ApplicationState) => TSelected,
+  checkForEquality?: (a: TSelected, b: TSelected) => boolean
+): TSelected => {
+  return useSelector<ApplicationState, TSelected>(selector, checkForEquality ? checkForEquality : equal)
+}

src/hooks/common/use-document-title-with-note-title.ts

@@ -5,14 +5,13 @@
  */
 
 import { useTranslation } from 'react-i18next'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from './use-application-state'
-import { ApplicationState } from '../../redux'
 import { useDocumentTitle } from './use-document-title'
 
 export const useDocumentTitleWithNoteTitle = (): void => {
   const { t } = useTranslation()
   const untitledNote = t('editor.untitledNote')
-  const noteTitle = useSelector((state: ApplicationState) => state.noteDetails.noteTitle)
+  const noteTitle = useApplicationState((state) => state.noteDetails.noteTitle)
 
   useDocumentTitle(noteTitle === '' ? untitledNote : noteTitle)
 }

src/hooks/common/use-document-title.ts

@@ -5,11 +5,10 @@
  */
 
 import { useEffect } from 'react'
-import { useSelector } from 'react-redux'
+import { useApplicationState } from './use-application-state'
-import { ApplicationState } from '../../redux'
 
 export const useDocumentTitle = (title?: string): void => {
-  const brandingName = useSelector((state: ApplicationState) => state.config.branding.name)
+  const brandingName = useApplicationState((state) => state.config.branding.name)
 
   useEffect(() => {
     document.title = `${title ? title + ' - ' : ''}HedgeDoc ${brandingName ? ` @ ${brandingName}` : ''}`

src/hooks/common/use-is-dark-mode-activated.ts

@@ -4,9 +4,8 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { useSelector } from 'react-redux'
+import { useApplicationState } from './use-application-state'
-import { ApplicationState } from '../../redux'
 
 export const useIsDarkModeActivated = (): boolean => {
-  return useSelector((state: ApplicationState) => state.darkMode.darkMode)
+  return useApplicationState((state) => state.darkMode.darkMode)
 }

src/hooks/common/use-note-markdown-content.ts

@@ -4,9 +4,8 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { useSelector } from 'react-redux'
+import { useApplicationState } from './use-application-state'
-import { ApplicationState } from '../../redux'
 
 export const useNoteMarkdownContent = (): string => {
-  return useSelector((state: ApplicationState) => state.noteDetails.markdownContent)
+  return useApplicationState((state) => state.noteDetails.markdownContent)
 }