Initial subscription impl

graph/context.js

@@ -31,7 +31,7 @@ const decorateContextPlugins = (context, contextPlugins) => contextPlugins.reduc
  * Stores the request context.
  */
 class Context {
-  constructor({user = null}) {
+  constructor({user = null}, pubsub) {
 
     // Load the current logged in user to `user`, otherwise this'll be null.
     if (user) {
@@ -46,6 +46,9 @@ class Context {
 
     // Decorate the plugin context.
     this.plugins = decorateContextPlugins(this, contextPlugins);
+
+    // Bind the publish/subscribe to the context.
+    this.pubsub = pubsub;
   }
 }
 

graph/index.js

@@ -1,7 +1,15 @@
 const schema = require('./schema');
 const Context = require('./context');
 
+const {connectionOptions} = require('../services/redis');
+const {RedisPubSub} = require('graphql-redis-subscriptions');
+const {SubscriptionManager} = require('graphql-subscriptions');
+const {SubscriptionServer} = require('subscriptions-transport-ws');
+
+const pubsub = new RedisPubSub(connectionOptions);
+
 module.exports = {
+  pubsub,
   createGraphOptions: (req) => ({
 
     // Schema is created already, so just include it.
@@ -9,6 +17,25 @@ module.exports = {
 
     // Load in the new context here, this'll create the loaders + mutators for
     // the lifespan of this request.
-    context: new Context(req)
+    context: new Context(req, pubsub)
+  }),
+  createSubscriptionManager: (server, path) => new SubscriptionServer({
+    subscriptionManager: new SubscriptionManager({
+      schema,
+      pubsub,
+      setupFunctions: {
+        commentAdded: (options, args) => ({
+          commentAdded: {
+            filter: (comment) => comment.asset_id === args.asset_id
+          },
+        }),
+      }
+    }),
+    // onConnect: (connectionParams, webSocket) => {
+    //   console.log(webSocket.upgradeReq.headers);
+    // }
+  }, {
+    server,
+    path
   })
 };

graph/mutators/comment.js

@@ -16,7 +16,7 @@ const Wordlist = require('../../services/wordlist');
  * @param  {String} [status='NONE'] the status of the new comment
  * @return {Promise}              resolves to the created comment
  */
-const createComment = ({user, loaders: {Comments}}, {body, asset_id, parent_id = null}, status = 'NONE') => {
+const createComment = ({user, loaders: {Comments}, pubsub}, {body, asset_id, parent_id = null}, status = 'NONE') => {
 
   let tags = [];
   if (user.hasRoles('ADMIN') || user.hasRoles('MODERATOR')) {
@@ -44,6 +44,9 @@ const createComment = ({user, loaders: {Comments}}, {body, asset_id, parent_id =
         Comments.parentCountByAssetID.incr(asset_id);
       }
       Comments.countByAssetID.incr(asset_id);
+
+      // Publish the newly added comment via the subscription.
+      pubsub.publish('commentAdded', comment);
     }
 
     return comment;

graph/resolvers/index.js

@@ -16,6 +16,7 @@ const LikeAction = require('./like_action');
 const RootMutation = require('./root_mutation');
 const RootQuery = require('./root_query');
 const Settings = require('./settings');
+const Subscription = require('./subscription');
 const UserError = require('./user_error');
 const User = require('./user');
 const ValidationUserError = require('./validation_user_error');
@@ -39,6 +40,7 @@ let resolvers = {
   RootMutation,
   RootQuery,
   Settings,
+  Subscription,
   UserError,
   User,
   ValidationUserError,

graph/resolvers/subscription.js

@@ -0,0 +1,7 @@
+const Subscription = {
+  commentAdded(comment) {
+    return comment;
+  }
+};
+
+module.exports = Subscription;

graph/typeDefs.graphql

@@ -706,6 +706,14 @@ type RootMutation {
   removeCommentTag(id: ID!, tag: String!): RemoveCommentTagResponse
 }
 
+################################################################################
+## Subscriptions
+################################################################################
+
+type Subscription {
+  commentAdded(asset_id: ID!): Comment
+}
+
 ################################################################################
 ## Schema
 ################################################################################
@@ -713,4 +721,5 @@ type RootMutation {
 schema {
   query: RootQuery
   mutation: RootMutation
+  subscription: Subscription
 }