Draft: Setup subsriptions for backend+frontend

Please clean up this commit and squash it later on.

backend/package.json

@@ -96,6 +96,7 @@
     "request": "~2.88.0",
     "sanitize-html": "~1.21.1",
     "slug": "~2.1.0",
+    "subscriptions-transport-ws": "^0.9.16",
     "trunc-html": "~1.1.2",
     "uuid": "~3.4.0",
     "validator": "^12.1.0",

backend/src/config/index.js

@@ -49,6 +49,7 @@ export const serverConfigs = {
   CLIENT_URI,
   GRAPHQL_URI,
   PUBLIC_REGISTRATION: process.env.PUBLIC_REGISTRATION === 'true',
+  SUBSCRIPTIONS_PATH: '/subscriptions',
 }
 
 export const developmentConfigs = {

backend/src/index.js

@@ -1,9 +1,10 @@
 import createServer from './server'
 import CONFIG from './config'
 
-const { app } = createServer()
+const { app, server, httpServer } = createServer()
 const url = new URL(CONFIG.GRAPHQL_URI)
-app.listen({ port: url.port }, () => {
+httpServer.listen({ port: url.port }, () => {
   /* eslint-disable-next-line no-console */
-  console.log(`GraphQLServer ready at ${CONFIG.GRAPHQL_URI} 🚀`)
+  console.log(`🚀 Server ready at http://localhost:${url.port}${server.graphqlPath}`)
+  console.log(`🚀 Subscriptions ready at ws://localhost:${url.port}${server.subscriptionsPath}`)
 })

backend/src/schema/resolvers/posts.js

@@ -5,6 +5,11 @@ import { UserInputError } from 'apollo-server'
 import fileUpload from './fileUpload'
 import Resolver from './helpers/Resolver'
 import { filterForMutedUsers } from './helpers/filterForMutedUsers'
+import { PubSub } from 'apollo-server'
+
+const pubsub = new PubSub();
+const POST_ADDED = 'POST_ADDED';
+
 
 const maintainPinnedPosts = params => {
   const pinnedPostFilter = { pinned: true }
@@ -17,6 +22,12 @@ const maintainPinnedPosts = params => {
 }
 
 export default {
+  Subscription: {
+    postAdded: {
+      // Additional event labels can be passed to asyncIterator creation
+      subscribe: () => pubsub.asyncIterator([POST_ADDED]),
+    },
+  },
   Query: {
     Post: async (object, params, context, resolveInfo) => {
       params = await filterForMutedUsers(params, context)
@@ -102,6 +113,7 @@ export default {
       })
       try {
         const [post] = await writeTxResultPromise
+        pubsub.publish(POST_ADDED, { postAdded: post });
         return post
       } catch (e) {
         if (e.code === 'Neo.ClientError.Schema.ConstraintValidationFailed')

backend/src/schema/types/schema.gql

@@ -1,3 +1,7 @@
+type Subscription {
+  postAdded: Post
+}
+
 type Mutation {
   # Get a JWT Token for the given Email and password
   login(email: String!, password: String!): String!

backend/src/server.js

@@ -1,6 +1,9 @@
 import express from 'express'
+import http from 'http'
 import helmet from 'helmet'
 import { ApolloServer } from 'apollo-server-express'
+
+
 import CONFIG from './config'
 import middleware from './middleware'
 import { getNeode, getDriver } from './db/neo4j'
@@ -8,10 +11,11 @@ import decode from './jwt/decode'
 import schema from './schema'
 import webfinger from './activitypub/routes/webfinger'
 
+
 const driver = getDriver()
 const neode = getNeode()
 
-export const context = async ({ req }) => {
+const getContext = async (req) => {
     const user = await decode(driver, req.headers.authorization)
     return {
       driver,
@@ -23,11 +27,25 @@ export const context = async ({ req }) => {
       },
     }
 }
+export const context = async (options) => {
+  const { connection, req } = options
+  if (connection) {
+    return connection.context
+  } else {
+    return getContext(req)
+  }
+}
 
 const createServer = options => {
   const defaults = {
     context,
     schema: middleware(schema),
+    subscriptions: {
+      onConnect: (connectionParams, webSocket) => {
+        console.log('connectionParams', connectionParams)
+        return getContext(connectionParams)
+      },
+    },
     debug: !!CONFIG.DEBUG,
     tracing: !!CONFIG.DEBUG,
     formatError: error => {
@@ -46,8 +64,11 @@ const createServer = options => {
   app.use('/.well-known/', webfinger())
   app.use(express.static('public'))
   server.applyMiddleware({ app, path: '/' })
+  const httpServer = http.createServer(app);
+  server.installSubscriptionHandlers(httpServer);
 
-  return { server, app }
+
+  return { server, httpServer, app }
 }
 
 export default createServer

backend/yarn.lock

@@ -1175,7 +1175,7 @@
     url-regex "~4.1.1"
     video-extensions "~1.1.0"
 
-"@metascraper/helpers@^5.10.5", "@metascraper/helpers@^5.10.6":
+"@metascraper/helpers@^5.10.6":
   version "5.10.6"
   resolved "https://registry.yarnpkg.com/@metascraper/helpers/-/helpers-5.10.6.tgz#0b786607212925a577926fd0cd0313a49de3499c"
   integrity sha512-/jvhlM3RKGYMoUK8D8S1r3tN03/EYizCqWF7zDx0aBMC8Ihp33DRGs9oNdsgkgwzVF7O/YpDm55l9K+qVJlsyQ==
@@ -7918,6 +7918,11 @@ serve-static@1.14.1:
   version "1.14.1"
   resolved "https://registry.yarnpkg.com/serve-static/-/serve-static-1.14.1.tgz#666e636dc4f010f7ef29970a88a674320898b2f9"
   integrity sha512-JMrvUwE54emCYWlTI+hGrGv5I8dEwmco/00EvkzIIsR7MqrHonbD9pO2MOfFnpFntl7ecpZs+3mW+XbQZu9QCg==
+  dependencies:
+    encodeurl "~1.0.2"
+    escape-html "~1.0.3"
+    parseurl "~1.3.3"
+    send "0.17.1"
 
 set-blocking@^2.0.0, set-blocking@~2.0.0:
   version "2.0.0"

webapp/pages/index.vue

@@ -74,6 +74,16 @@ import { mapGetters, mapMutations } from 'vuex'
 import { filterPosts } from '~/graphql/PostQuery.js'
 import PostMutations from '~/graphql/PostMutations'
 import UpdateQuery from '~/components/utils/UpdateQuery'
+import gql from 'graphql-tag'
+import {
+  userFragment,
+  postFragment,
+  commentFragment,
+  postCountsFragment,
+  userCountsFragment,
+  locationAndBadgesFragment,
+  tagsCategoriesAndPinnedFragment,
+} from '~/graphql/Fragments'
 
 export default {
   components: {
@@ -213,6 +223,36 @@ export default {
         this.posts = Post
       },
       fetchPolicy: 'cache-and-network',
+      subscribeToMore: {
+        document: gql`
+    ${userFragment}
+    ${userCountsFragment}
+    ${locationAndBadgesFragment('EN')}
+    ${postFragment}
+    ${postCountsFragment}
+    ${tagsCategoriesAndPinnedFragment}
+
+        subscription Post {
+          postAdded {
+            ...post
+            ...postCounts
+            ...tagsCategoriesAndPinned
+            author {
+              ...user
+              ...userCounts
+              ...locationAndBadges
+            }
+          }
+        }`,
+        // Mutate the previous result
+        updateQuery: (previousResult, { subscriptionData }) => {
+          console.log('previousResult', previousResult)
+          console.log('subscriptionData', subscriptionData)
+          const { data: { postAdded: newPost } } = subscriptionData
+          return { Post: [newPost, ...previousResult.Post] }
+          // Here, return the new result from the previous with the new data
+        },
+      }
     },
   },
 }

webapp/plugins/apollo-config.js

@@ -9,6 +9,7 @@ export default ({ app }) => {
   const backendUrl = process.env.GRAPHQL_URI || 'http://localhost:4000'
 
   return {
+    wsEndpoint: 'ws://localhost:4000/graphql', // optional
     httpEndpoint: process.server ? backendUrl : '/api',
     httpLinkOptions: {
       credentials: 'same-origin',
@@ -16,7 +17,7 @@ export default ({ app }) => {
     credentials: true,
     tokenName: 'human-connection-token',
     persisting: false,
-    websocketsOnly: false,
+    websocketsOnly: true,
     cache: new InMemoryCache({ fragmentMatcher }),
   }
 }