longPolling: false option (#5154)

* longPolling: false option

* please the eslint god

Author: boutell

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 * Translation strings added for the layout- and layout-column-widgets.
 * When switching locale from the doc editor, ask if the user wants to localize the current document in the target locale or want to start a blank document.
+* Introduced a new `longPolling: false` option for the `@apostrophecms/notification` module. This eliminates long-pending requests when logged in, but also slows down the delivery of notifications. The behavior can be tuned further via the `pollingInterval` option, which defaults to `5000` milliseconds.
 
 ### Changes
 

modules/@apostrophecms/notification/index.js

@@ -4,6 +4,12 @@
 //
 // ## Options
 //
+// ### `longPolling`: by default, to provide a swift response, ApostropheCMS
+// keeps a request for new notifications alive until the long polling
+// timeout expires (see below). However, `longPolling: false` can be used
+// to give an immediate response, in which case the front end will poll
+// the old-fashioned way, respecting the `pollingInterval`.
+//
 // ### `queryInterval`: interval in milliseconds between MongoDB
 // queries while long polling for notifications. Defaults to 500
 // (1/2 second). Set it longer if you prefer fewer queries, however
@@ -15,12 +21,22 @@
 // Defaults to 10000 (10 seconds) to avoid typical proxy server timeouts.
 // Until it times out the request will keep making MongoDB queries to
 // see if any new notifications are available (long polling).
+//
+// ### `pollingInterval`: when `longPolling` is set to `false`, this
+// option determines how often the browser polls for new notifications.
+// Not used when `longPolling` is `true` (the default).
+// `pollingInterval` defaults to 5000 (5 seconds).
 
 const delay = require('bluebird').delay;
 
 module.exports = {
   options: {
-    alias: 'notification'
+    alias: 'notification',
+    longPolling: true,
+    longPollingTimeout: 10000,
+    queryInterval: 1000,
+    // Used only when longPolling is false
+    pollingInterval: 5000
   },
   extend: '@apostrophecms/module',
   async init(self) {
@@ -64,7 +80,10 @@ module.exports = {
         return await attempt();
 
         async function attempt() {
-          if (Date.now() - start >= (self.options.longPollingTimeout || 10000)) {
+          if (
+            self.options.longPolling &&
+              (Date.now() - start >= self.options.longPollingTimeout)
+          ) {
             return {
               notifications: [],
               dismissed: []
@@ -75,11 +94,10 @@ module.exports = {
             modifiedOnOrSince,
             seenIds
           });
-          if (!notifications.length && !dismissed.length) {
+          if (self.options.longPolling && !notifications.length && !dismissed.length) {
             await delay(self.options.queryInterval || 1000);
             return attempt();
           }
-
           return {
             notifications,
             dismissed
@@ -208,7 +226,9 @@ module.exports = {
     return {
       getBrowserData(req) {
         return {
-          action: self.action
+          action: self.action,
+          longPolling: self.options.longPolling,
+          pollingInterval: self.options.pollingInterval
         };
       },
       // When used server-side, call with `req` as the first argument,

modules/@apostrophecms/ui/ui/apos/stores/notification.js

@@ -107,10 +107,13 @@ export const useNotificationStore = defineStore('notification', () => {
             return !res.dismissed.some((element) => notif._id === element._id);
           });
         }
-        // Long polling, we should reconnect promptly, the server
+        // If using long polling we should reconnect promptly, the server
         // is responsible for keeping that request open for a reasonable
         // amount of time if there are no new messages, not us
-        setTimeout(poll, 50);
+        const timeout = apos.notification.longPolling
+          ? 50
+          : apos.notification.pollingInterval;
+        setTimeout(poll, timeout);
       }
     } catch (err) {
       // eslint-disable-next-line no-console