initial notification draft

- implements new notification manager using connect api
- first use case of plugins using the plugin api

plugins/talk-plugin-notifications/server/NotificationManager.js

@@ -0,0 +1,174 @@
+const { get, groupBy, forEach } = require('lodash');
+const debug = require('debug')('talk-plugin-notifications');
+const { graphql } = require('graphql');
+
+class NotificationManager {
+  constructor(context) {
+    this.context = context;
+    this.registry = [];
+  }
+
+  /**
+   * register will include the notification handlers on the manager.
+   *
+   * @param {Array<Object>} handlers notification handlers to register
+   */
+  register(...handlers) {
+    this.registry.push(...handlers);
+  }
+
+  /**
+   * attach will setup the notifications by walking the registry and loading all
+   * the notification types onto the handler.
+   *
+   * @param {Object} broker the event emitter for the Talk events
+   */
+  attach(broker) {
+    const events = groupBy(this.registry, 'event');
+
+    forEach(events, (handlers, event) => {
+      debug(
+        `will now notify the [${handlers
+          .map(({ category }) => category)
+          .join(', ')}] handlers when the '${event}' event is emitted`
+      );
+      broker.on(event, this.handle(handlers));
+    });
+  }
+
+  /**
+   * handle will wrap a notification handler and attach it to the notification
+   * stream system.
+   *
+   * @param {Object} handler a notification handler
+   */
+  handle(handlers) {
+    return async (...args) =>
+      Promise.all(
+        handlers.map(async handler => {
+          // Grab the handler reference.
+          const { handle } = handler;
+
+          // Create a system context to send down.
+          const ctx = this.context.forSystem();
+
+          try {
+            // Attempt to create a notification out of it.
+            const notification = await handle(ctx, ...args);
+            if (!notification) {
+              return;
+            }
+
+            // Extract the notification details.
+            const { userID, date, context } = notification;
+
+            // Send the notification.
+            return this.send(ctx, userID, date, handler, context);
+          } catch (err) {
+            // TODO: handle error.
+            return;
+          }
+        })
+      );
+  }
+
+  /**
+   *
+   * @param {Object} ctx graph context
+   * @param {String} userID the user id for the user being sent the email
+   */
+  async getEmail(ctx, userID) {
+    const { connectors: { graph: { schema } } } = ctx;
+
+    // Get the email for the user.
+    const reply = await graphql(
+      schema,
+      `
+        query GetUserEmail($userID: ID!) {
+          user(id: $userID) {
+            email
+          }
+        }
+      `,
+      {},
+      ctx,
+      { userID }
+    );
+    if (reply.errors) {
+      throw reply.errors;
+    }
+
+    return get(reply, 'data.user.email', null);
+  }
+
+  async send(ctx, userID, date, handler, context) {
+    const {
+      connectors: { services: { Mailer, I18n: { t } } },
+      loaders: { Settings },
+    } = ctx;
+    const { category } = handler;
+
+    try {
+      // Get the settings.
+      const { organizationName = null } = await Settings.load(
+        'organizationName'
+      );
+      if (organizationName === null) {
+        // TODO: handle error
+        return;
+      }
+
+      // Get the User's email.
+      const to = await this.getEmail(ctx, userID);
+      if (!to) {
+        // TODO: handle error
+        return;
+      }
+
+      // Compose the subject for the email.
+      const subject = t(
+        `talk-plugin-notifications.categories.${category}.subject`,
+        organizationName
+      );
+
+      // Load the content into the comment.
+      const body = await this.getBody(ctx, handler, context);
+
+      // Send the notification to the user.
+      const task = await Mailer.send({
+        template: 'notification',
+        locals: { body, organizationName },
+        subject,
+        to,
+      });
+
+      debug(`Sent the notification for Job.ID[${task.id}]`);
+    } catch (err) {
+      // TODO: print out the error.
+      return;
+    }
+  }
+
+  /**
+   * getBody will return the body for the notification payload.
+   *
+   * @param {Object} ctx the graph context
+   * @param {Object} handler the notification handler
+   * @param {Mixed} context the notification context
+   */
+  async getBody(ctx, handler, context) {
+    const { connectors: { services: { I18n: { t } } } } = ctx;
+    const { category } = handler;
+
+    // Get the body replacement variables for the translation key.
+    const replacements = await handler.hydrate(ctx, category, context);
+
+    // Generate the body.
+    return t(
+      `talk-plugin-notifications.categories.${category}.body`,
+      ...replacements
+    );
+  }
+}
+
+module.exports = NotificationManager;

plugins/talk-plugin-notifications/server/connect.js

@@ -0,0 +1,72 @@
+const debug = require('debug')('talk-plugin-notifications');
+const path = require('path');
+const linkify = require('linkifyjs/html');
+const NotificationManager = require('./NotificationManager');
+
+module.exports = connectors => {
+  const {
+    graph: { subscriptions: { getBroker }, Context },
+    services: { Mailer, Plugins },
+  } = connectors;
+
+  // Setup the mailer. Other plugins registered before this one can replace the
+  // notification template by passing the same name + format for the template
+  // registration.
+  Mailer.templates.register(
+    path.join(__dirname, 'templates', 'notification.html.ejs'),
+    'notification',
+    'html'
+  );
+  Mailer.templates.register(
+    path.join(__dirname, 'templates', 'notification.txt.ejs'),
+    'notification',
+    'txt'
+  );
+
+  // Register the mail helpers. You can register your own helpers by calling
+  // this function in another plugin.
+  Mailer.registerHelpers({ linkify });
+
+  // Get the handle for the broker to attach to notifications.
+  const broker = getBroker();
+
+  // Create a NotificationManager to handle notifications.
+  const manager = new NotificationManager(Context);
+
+  // Get all the notification handlers. Additional plugins registered before
+  // this one can expose a `notifications` hook, that contains an array (or a
+  // single) notification handlers.
+  //
+  // A notification handler has the following form:
+  //
+  // {
+  //   event     // the graph event to listen for
+  //   handle    // the function called when the event is fired. It is called with
+  //             // the (ctx, arg1, arg2, ...) where arg1, arg2 are args from the
+  //             // event.
+  //   category  // the name representing the notification type (like 'reply')
+  //   hydrate   // returns the replacement parameters (in order!) to be used
+  //             // in the translation.
+  // }
+  //
+  const notificationHandlers = Plugins.get('server', 'notifications').reduce(
+    (notificationHandlers, { plugin, notifications }) => {
+      debug(
+        `registered the ${
+          plugin.name
+        } plugin for notifications ${notifications.map(
+          ({ category }) => category
+        )}`
+      );
+      notificationHandlers.push(...notifications);
+      return notificationHandlers;
+    },
+    []
+  );
+
+  // Attach all the notification handlers.
+  manager.register(...notificationHandlers);
+
+  // Attach the broker to the manager so it can listen for the events.
+  manager.attach(broker);
+};

plugins/talk-plugin-notifications/server/index.js

@@ -0,0 +1,14 @@
+const path = require('path');
+const connect = require('./connect');
+const typeDefs = require('./typeDefs');
+const resolvers = require('./resolvers');
+const router = require('./router');
+const translations = path.join(__dirname, 'translations.yml');
+
+module.exports = {
+  translations,
+  typeDefs,
+  resolvers,
+  connect,
+  router,
+};

plugins/talk-plugin-notifications/server/resolvers.js

@@ -0,0 +1,14 @@
+const { get } = require('lodash');
+
+module.exports = {
+  User: {
+    notificationSettings(user, args, { user: currentUser }) {
+      if (
+        currentUser &&
+        (currentUser.id === user.id || currentUser.can('VIEW_USER_STATUS'))
+      ) {
+        return get(user, 'metadata.notifications.settings');
+      }
+    },
+  },
+};

plugins/talk-plugin-notifications/server/router.js

@@ -0,0 +1,6 @@
+module.exports = router => {
+  router.get('/account/unsubscribe-notifications', async (req, res) => {
+    // TODO: implement
+    res.json({ ok: true });
+  });
+};

plugins/talk-plugin-notifications/server/templates/notification.html.ejs

@@ -0,0 +1,3 @@
+<p><%= linkify(body, {nl2br: true}) %></p>
+<p><%= t('talk-plugin-notifications.templates.footer', organizationName) %></p>
+<p><a href="<%= BASE_URL %>account/unsubscribe-notifications" target="_blank"><%= t('talk-plugin-notifications.templates.links.unsubscribe') %></a></p>

plugins/talk-plugin-notifications/server/templates/notification.txt.ejs

@@ -0,0 +1,7 @@
+<%= body %>
+
+<%= t('talk-plugin-notifications.templates.footer', organizationName) %>
+
+<%= t('talk-plugin-notifications.templates.links.unsubscribe') %>
+
+    <%= BASE_URL %>account/unsubscribe-notifications

plugins/talk-plugin-notifications/server/translations.yml

@@ -0,0 +1,6 @@
+en:
+  talk-plugin-notifications:
+    templates:
+      footer: "You received this notification because you are a commenter on {0} and you opted in to receive notifications."
+      links:
+        unsubscribe: "Unsubscribe from comment notifications"

plugins/talk-plugin-notifications/server/typeDefs.graphql

@@ -0,0 +1,7 @@
+type NotificationSettings {
+    onReply: Boolean!
+}
+
+type User {
+    notificationSettings: NotificationSettings
+}

plugins/talk-plugin-notifications/server/typeDefs.js

@@ -0,0 +1,7 @@
+const fs = require('fs');
+const path = require('path');
+
+module.exports = fs.readFileSync(
+  path.join(__dirname, 'typeDefs.graphql'),
+  'utf8'
+);