perf: optimize load of pagination items with caching

components/Application/JoinGuildsPublic/JoinGuildsPublic.tsx

@@ -22,12 +22,15 @@ export const JoinGuildsPublic: React.FC = () => {
     })
 
   useEffect(() => {
-    authentication.socket.on('guilds', (data: SocketData<GuildPublicType>) => {
-      handleSocketData({ data, setItems })
-    })
+    authentication?.socket?.on(
+      'guilds',
+      (data: SocketData<GuildPublicType>) => {
+        handleSocketData({ data, setItems })
+      }
+    )
 
     return () => {
-      authentication.socket.off('guilds')
+      authentication?.socket?.off('guilds')
     }
   }, [authentication.socket, setItems])
 

components/Authentication/Authentication.tsx

@@ -72,7 +72,7 @@ export const Authentication: React.FC<AuthenticationProps> = (props) => {
     } else {
       try {
         const { data } = await api.post<Tokens>('/users/signin', formData)
-        const authentication = new AuthenticationClass(data)
+        const authentication = new AuthenticationClass(data, true)
         authentication.signin()
         await router.push('/application')
         return null

components/Authentication/AuthenticationSocialMedia.tsx

@@ -24,7 +24,7 @@ export const AuthenticationSocialMedia: React.FC = () => {
   useEffect(() => {
     const data = router.query
     if (isTokens(data)) {
-      const authentication = new Authentication(data)
+      const authentication = new Authentication(data, true)
       authentication.signin()
       router.push('/application').catch(() => {})
     }

contexts/Channels.tsx

@@ -6,6 +6,7 @@ import { useAuthentication } from '../tools/authentication'
 import { Channel, ChannelWithDefaultChannelId } from '../models/Channel'
 import { GuildsChannelsPath } from '../components/Application'
 import { handleSocketData, SocketData } from '../tools/handleSocketData'
+import { CacheKey, CHANNELS_CACHE_KEY } from '../tools/cache'
 
 export interface Channels {
   channels: Channel[]
@@ -27,6 +28,8 @@ export const ChannelsProvider: React.FC<
   const router = useRouter()
   const { authentication } = useAuthentication()
 
+  const cacheKey: CacheKey = `${path.guildId}-${CHANNELS_CACHE_KEY}`
+
   const {
     items: channels,
     hasMore,
@@ -35,14 +38,15 @@ export const ChannelsProvider: React.FC<
     setItems
   } = usePagination<Channel>({
     api: authentication.api,
-    url: `/guilds/${path.guildId}/channels`
+    url: `/guilds/${path.guildId}/channels`,
+    cacheKey
   })
 
   useEffect(() => {
-    authentication.socket.on(
+    authentication?.socket?.on(
       'channels',
       async (data: SocketData<ChannelWithDefaultChannelId>) => {
-        handleSocketData({ data, setItems })
+        handleSocketData({ data, setItems, cacheKey })
         if (data.action === 'delete') {
           await router.push(
             `/application/${path.guildId}/${data.item.defaultChannelId}`
@@ -52,9 +56,9 @@ export const ChannelsProvider: React.FC<
     )
 
     return () => {
-      authentication.socket.off('channels')
+      authentication?.socket?.off('channels')
     }
-  }, [authentication.socket, path.guildId, router, setItems])
+  }, [authentication.socket, path.guildId, router, setItems, cacheKey])
 
   useEffect(() => {
     resetPagination()

contexts/GuildMember.tsx

@@ -47,7 +47,7 @@ export const GuildMemberProvider: React.FC<
   }, [path, authentication.api])
 
   useEffect(() => {
-    authentication.socket.on(
+    authentication?.socket?.on(
       'guilds',
       async (data: SocketData<GuildWithDefaultChannelId>) => {
         if (data.item.id === path.guildId) {
@@ -72,7 +72,7 @@ export const GuildMemberProvider: React.FC<
     )
 
     return () => {
-      authentication.socket.off('guilds')
+      authentication?.socket?.off('guilds')
     }
   }, [authentication.socket, path.guildId, router])
 

contexts/Guilds.tsx

@@ -4,6 +4,7 @@ import { NextPage, usePagination } from '../hooks/usePagination'
 import { useAuthentication } from '../tools/authentication'
 import { GuildWithDefaultChannelId } from '../models/Guild'
 import { handleSocketData, SocketData } from '../tools/handleSocketData'
+import { GUILDS_CACHE_KEY } from '../tools/cache'
 
 export interface Guilds {
   guilds: GuildWithDefaultChannelId[]
@@ -29,19 +30,20 @@ export const GuildsProvider: React.FC<React.PropsWithChildren<{}>> = (
     setItems
   } = usePagination<GuildWithDefaultChannelId>({
     api: authentication.api,
-    url: '/guilds'
+    url: '/guilds',
+    cacheKey: GUILDS_CACHE_KEY
   })
 
   useEffect(() => {
-    authentication.socket.on(
+    authentication?.socket?.on(
       'guilds',
       (data: SocketData<GuildWithDefaultChannelId>) => {
-        handleSocketData({ data, setItems })
+        handleSocketData({ data, setItems, cacheKey: GUILDS_CACHE_KEY })
       }
     )
 
     return () => {
-      authentication.socket.off('guilds')
+      authentication?.socket?.off('guilds')
     }
   }, [authentication.socket, setItems])
 

contexts/Members.tsx

@@ -6,6 +6,7 @@ import { MemberWithPublicUser } from '../models/Member'
 import { GuildsChannelsPath } from '../components/Application'
 import { handleSocketData, SocketData } from '../tools/handleSocketData'
 import { User } from '../models/User'
+import { CacheKey, MEMBERS_CACHE_KEY } from '../tools/cache'
 
 export interface Members {
   members: MemberWithPublicUser[]
@@ -27,6 +28,8 @@ export const MembersProviders: React.FC<
 
   const { authentication } = useAuthentication()
 
+  const cacheKey: CacheKey = `${path.guildId}-${MEMBERS_CACHE_KEY}`
+
   const {
     items: members,
     hasMore,
@@ -35,18 +38,19 @@ export const MembersProviders: React.FC<
     setItems
   } = usePagination<MemberWithPublicUser>({
     api: authentication.api,
-    url: `/guilds/${path.guildId}/members`
+    url: `/guilds/${path.guildId}/members`,
+    cacheKey
   })
 
   useEffect(() => {
-    authentication.socket.on(
+    authentication?.socket?.on(
       'members',
       (data: SocketData<MemberWithPublicUser>) => {
-        handleSocketData({ data, setItems })
+        handleSocketData({ data, setItems, cacheKey })
       }
     )
 
-    authentication.socket.on('users', (data: SocketData<User>) => {
+    authentication?.socket?.on('users', (data: SocketData<User>) => {
       setItems((oldItems) => {
         const newItems = [...oldItems]
         switch (data.action) {
@@ -65,10 +69,10 @@ export const MembersProviders: React.FC<
     })
 
     return () => {
-      authentication.socket.off('members')
-      authentication.socket.off('users')
+      authentication?.socket?.off('members')
+      authentication?.socket?.off('users')
     }
-  }, [authentication.socket, setItems])
+  }, [authentication.socket, setItems, cacheKey])
 
   useEffect(() => {
     resetPagination()

contexts/Messages.tsx

@@ -5,6 +5,7 @@ import { useAuthentication } from '../tools/authentication'
 import { MessageWithMember } from '../models/Message'
 import { GuildsChannelsPath } from '../components/Application'
 import { handleSocketData, SocketData } from '../tools/handleSocketData'
+import { CacheKey, MESSAGES_CACHE_KEY } from '../tools/cache'
 
 export interface Messages {
   messages: MessageWithMember[]
@@ -25,6 +26,8 @@ export const MessagesProvider: React.FC<
   const { path, children } = props
   const { authentication, user } = useAuthentication()
 
+  const cacheKey: CacheKey = `${path.channelId}-${MESSAGES_CACHE_KEY}`
+
   const {
     items: messages,
     hasMore,
@@ -34,11 +37,12 @@ export const MessagesProvider: React.FC<
   } = usePagination<MessageWithMember>({
     api: authentication.api,
     url: `/channels/${path.channelId}/messages`,
-    inverse: true
+    inverse: true,
+    cacheKey
   })
 
   useEffect(() => {
-    authentication.socket.on(
+    authentication?.socket?.on(
       'messages',
       (data: SocketData<MessageWithMember>) => {
         if (data.item.channelId === path.channelId) {
@@ -48,7 +52,7 @@ export const MessagesProvider: React.FC<
           const isAtBottom =
             messagesDiv.scrollHeight - messagesDiv.scrollTop <=
             messagesDiv.clientHeight
-          handleSocketData({ data, setItems })
+          handleSocketData({ data, setItems, cacheKey })
           if (
             data.action === 'create' &&
             (isAtBottom || data.item.member.userId === user.id)
@@ -60,9 +64,9 @@ export const MessagesProvider: React.FC<
     )
 
     return () => {
-      authentication.socket.off('messages')
+      authentication?.socket?.off('messages')
     }
-  }, [authentication.socket, setItems, path, user.id])
+  }, [authentication.socket, setItems, path, user.id, cacheKey])
 
   useEffect(() => {
     resetPagination()

hooks/usePagination.ts

@@ -2,6 +2,11 @@ import { useState, useRef, useCallback } from 'react'
 import { AxiosInstance } from 'axios'
 
 import { FetchState } from './useFetchState'
+import {
+  CacheKey,
+  getPaginationCache,
+  savePaginationCache
+} from '../tools/cache'
 
 export interface Query {
   [key: string]: string
@@ -13,6 +18,11 @@ export interface UsePaginationOptions {
   api: AxiosInstance
   url: string
   inverse?: boolean
+  cacheKey?: CacheKey
+}
+
+export interface PaginationItem {
+  id: number
 }
 
 export type SetItems<T> = React.Dispatch<React.SetStateAction<T[]>>
@@ -25,16 +35,25 @@ export interface UsePaginationResult<T> {
   setItems: SetItems<T>
 }
 
-export const usePagination = <T extends { id: number }>(
+export const usePagination = <T extends PaginationItem>(
   options: UsePaginationOptions
 ): UsePaginationResult<T> => {
-  const { api, url, inverse = false } = options
+  const { api, url, inverse = false, cacheKey } = options
 
   const [items, setItems] = useState<T[]>([])
   const [hasMore, setHasMore] = useState(true)
   const fetchState = useRef<FetchState>('idle')
   const afterId = useRef<number | null>(null)
 
+  const updateAfterId = (newItems: T[]): void => {
+    if (!inverse) {
+      afterId.current =
+        newItems.length > 0 ? newItems[newItems.length - 1].id : null
+    } else {
+      afterId.current = newItems.length > 0 ? newItems[0].id : null
+    }
+  }
+
   const nextPageAsync: NextPageAsync = useCallback(
     async (query) => {
       if (fetchState.current !== 'idle') {
@@ -49,19 +68,22 @@ export const usePagination = <T extends { id: number }>(
       const { data: newItems } = await api.get<T[]>(
         `${url}?${searchParameters.toString()}`
       )
-      if (!inverse) {
-        afterId.current =
-          newItems.length > 0 ? newItems[newItems.length - 1].id : null
-      } else {
-        afterId.current = newItems.length > 0 ? newItems[0].id : null
-      }
+      updateAfterId(newItems)
       setItems((oldItems) => {
-        return inverse ? [...newItems, ...oldItems] : [...oldItems, ...newItems]
+        const updatedItems = inverse
+          ? [...newItems, ...oldItems]
+          : [...oldItems, ...newItems]
+        if (cacheKey != null) {
+          savePaginationCache(cacheKey, updatedItems)
+        }
+        return updatedItems
       })
       setHasMore(newItems.length > 0)
       fetchState.current = 'idle'
     },
-    [api, url, inverse]
+
+    // eslint-disable-next-line react-hooks/exhaustive-deps -- We don't want infinite loops with updateAfterId
+    [api, url, inverse, cacheKey]
   )
 
   const nextPage: NextPage = useCallback(
@@ -80,9 +102,17 @@ export const usePagination = <T extends { id: number }>(
   )
 
   const resetPagination = useCallback((): void => {
-    afterId.current = null
-    setItems([])
-  }, [])
+    if (cacheKey == null) {
+      afterId.current = null
+      setItems([])
+    } else {
+      const newItems = getPaginationCache<T>(cacheKey)
+      setItems(newItems)
+      updateAfterId(newItems)
+    }
+
+    // eslint-disable-next-line react-hooks/exhaustive-deps -- We don't want infinite loops with updateAfterId
+  }, [cacheKey])
 
   return { items, hasMore, nextPage, resetPagination, setItems }
 }

next.config.js

@@ -7,7 +7,7 @@ const nextTranslate = require('next-translate')
 /** @type {import("next").NextConfig} */
 module.exports = nextTranslate(
   nextPWA({
-    reactStrictMode: true,
+    reactStrictMode: false,
     images: {
       domains: [
         'api.thream.divlo.fr',

pages/_app.tsx

@@ -28,6 +28,9 @@ const Application = ({ Component, pageProps }: AppProps): JSX.Element => {
     }
     window.addEventListener('resize', appHeight)
     appHeight()
+    return () => {
+      window.removeEventListener('resize', appHeight)
+    }
   }, [lang])
 
   return (

tools/authentication/Authentication.ts

@@ -9,27 +9,36 @@ import { fetchRefreshToken } from './authenticationFromServerSide'
 export class Authentication {
   public tokens: Tokens
   public accessTokenAge: number
-  public socket: Socket
+  public socket?: Socket
   public api: AxiosInstance
 
-  constructor(tokens: Tokens) {
+  constructor(tokens: Tokens, disableSocketIO: boolean = false) {
     this.tokens = tokens
     this.accessTokenAge = Date.now()
-    this.socket = io(API_URL, {
-      auth: { token: `Bearer ${tokens.accessToken}` }
-    })
-    this.socket.on('connect_error', (error) => {
-      if (error.message.startsWith('Unauthorized')) {
-        fetchRefreshToken(this.tokens.refreshToken)
-          .then(({ accessToken }) => {
-            this.setAccessToken(accessToken)
-          })
-          .catch(async () => {
-            this.signout()
-            return await Promise.reject(error)
-          })
-      }
-    })
+    if (disableSocketIO || typeof window === 'undefined') {
+      this.socket = undefined
+    } else {
+      this.socket = io(API_URL, {
+        auth: { token: `Bearer ${tokens.accessToken}` }
+      })
+      this.socket.on('connect', () => {
+        console.log(
+          `Connected to socket with clientId: ${this.socket?.id ?? 'undefined'}`
+        )
+      })
+      this.socket.on('connect_error', (error) => {
+        if (error.message.startsWith('Unauthorized')) {
+          fetchRefreshToken(this.tokens.refreshToken)
+            .then(({ accessToken }) => {
+              this.setAccessToken(accessToken)
+            })
+            .catch(async () => {
+              this.signout()
+              return await Promise.reject(error)
+            })
+        }
+      })
+    }
     this.api = axios.create({
       baseURL: API_URL,
       headers: {
@@ -83,13 +92,14 @@ export class Authentication {
     this.tokens.accessToken = accessToken
     this.accessTokenAge = Date.now()
     const token = `${this.tokens.type} ${this.tokens.accessToken}`
-    if (typeof this.socket.auth !== 'function') {
+    if (typeof this?.socket?.auth !== 'function' && this.socket != null) {
       this.socket.auth.token = token
     }
   }
 
   public signout(): void {
     cookies.remove('refreshToken')
+    window.localStorage.clear()
     window.location.href = '/authentication/signin'
   }
 

tools/authentication/AuthenticationContext.tsx

@@ -25,7 +25,8 @@ export const AuthenticationProvider: React.FC<
   const [user, setUser] = useState<UserCurrent>(props.authentication.user)
 
   const authentication = useMemo(() => {
-    return new Authentication(props.authentication.tokens)
+    const disableSocketIO = typeof window === 'undefined'
+    return new Authentication(props.authentication.tokens, disableSocketIO)
 
     // eslint-disable-next-line react-hooks/exhaustive-deps -- We only want to run this memo once
   }, [])
@@ -33,7 +34,9 @@ export const AuthenticationProvider: React.FC<
   useEffect(() => {
     setLanguage(props.authentication.user.settings.language).catch(() => {})
     setTheme(props.authentication.user.settings.theme)
-
+    return () => {
+      authentication?.socket?.disconnect()
+    }
     // eslint-disable-next-line react-hooks/exhaustive-deps -- We only want to run this effect once
   }, [])
 

tools/authentication/authenticationFromServerSide.ts

@@ -71,7 +71,7 @@ export const authenticationFromServerSide = (
       } else {
         try {
           let data: any = {}
-          const authentication = new Authentication(tokens)
+          const authentication = new Authentication(tokens, true)
           const { data: currentUser } = await authentication.api.get<
             unknown,
             AxiosResponse<UserCurrent>

tools/cache.ts

@@ -0,0 +1,34 @@
+import { PaginationItem } from '../hooks/usePagination'
+
+export const GUILDS_CACHE_KEY = 'guilds' as const
+export const CHANNELS_CACHE_KEY = 'channels' as const
+export const MEMBERS_CACHE_KEY = 'members' as const
+export const MESSAGES_CACHE_KEY = 'messages' as const
+
+export type CacheKey =
+  | typeof GUILDS_CACHE_KEY
+  | `${number}-${typeof CHANNELS_CACHE_KEY}`
+  | `${number}-${typeof MEMBERS_CACHE_KEY}`
+  | `${number}-${typeof MESSAGES_CACHE_KEY}`
+
+export const getPaginationCache = <T extends PaginationItem>(
+  key: CacheKey
+): T[] => {
+  const cache = localStorage.getItem(key)
+  if (cache != null) {
+    try {
+      const data = JSON.parse(cache)
+      if (Array.isArray(data)) {
+        return data
+      }
+    } catch {}
+  }
+  return []
+}
+
+export const savePaginationCache = <T extends PaginationItem>(
+  key: CacheKey,
+  data: T[]
+): void => {
+  localStorage.setItem(key, JSON.stringify(data))
+}

tools/handleSocketData.ts

@@ -1,4 +1,5 @@
 import { SetItems } from '../hooks/usePagination'
+import { CacheKey, savePaginationCache } from './cache'
 
 export interface Item {
   id: number
@@ -13,6 +14,7 @@ export interface SocketData<T extends Item = Item> {
 export interface HandleSocketDataOptions<T extends Item = Item> {
   setItems: SetItems<T>
   data: SocketData<T>
+  cacheKey?: CacheKey
 }
 
 export type SocketListener = (data: SocketData) => void
@@ -20,7 +22,8 @@ export type SocketListener = (data: SocketData) => void
 export const handleSocketData = <T extends Item = Item>(
   options: HandleSocketDataOptions<T>
 ): void => {
-  const { data, setItems } = options
+  const { data, setItems, cacheKey } = options
+  console.log('socket.io data received: ', data)
 
   setItems((oldItems) => {
     const newItems = [...oldItems]
@@ -47,6 +50,9 @@ export const handleSocketData = <T extends Item = Item>(
         break
       }
     }
+    if (cacheKey != null) {
+      savePaginationCache(cacheKey, newItems)
+    }
     return newItems
   })
 }