feat(sync): Display the state of the connection to the users

umap/static/umap/js/modules/sync/engine.js

@@ -48,7 +48,7 @@ const MAX_RECONNECT_DELAY = 32000;
  * ```
  */
 export class SyncEngine {
-  constructor(map, urls, server) {
+  constructor(map, websocketTokenURI, websocketURI, server) {
     this.updaters = {
       map: new MapUpdater(map),
       feature: new FeatureUpdater(map),
@@ -58,14 +58,12 @@ export class SyncEngine {
     this._operations = new Operations()
     this._server = server
 
-    // Store URIs to avoid persisting the map
-    // mainly to ensure separation of concerns.
-    this._websocketTokenURI = urls.get('map_websocket_auth_token', {
-      map_id: map.options.umap_id,
-    })
-    this._websocketURI = map.options.websocketURI
+    this._websocketTokenURI = websocketTokenURI
+    this._websocketURI = websocketURI
+
     this._reconnectTimeout = null;
     this._reconnectDelay = RECONNECT_DELAY;
+    this.websocketConnected = false;
   }
 
   /**
@@ -92,9 +90,13 @@ export class SyncEngine {
   onConnection() {
     this._reconnectTimeout = null;
     this._reconnectDelay = RECONNECT_DELAY;
+    this.websocketConnected = true;
   }
 
   reconnect() {
+    this.websocketConnected = false;
+    this.updaters.map.update({ key: 'numberOfConnectedPeers' })
+  
     console.log("reconnecting in ", this._reconnectDelay, " ms")
     this._reconnectTimeout = setTimeout(() => {
       if (this._reconnectDelay < MAX_RECONNECT_DELAY) {

umap/static/umap/js/umap.controls.js

@@ -661,30 +661,43 @@ const ControlsMixin = {
       })
     }
 
+    if (this.options.syncEnabled) {
       const connectedPeers = this.sync.getNumberOfConnectedPeers()
-    if (connectedPeers !== 0) {
+      let hoverMessage = ''
+
+      if (connectedPeers !== 0 || !this.sync.websocketConnected) {
         const connectedPeersCount = L.DomUtil.createButton(
           'leaflet-control-connected-peers',
           rightContainer,
           ''
         )
+        if (this.sync.websocketConnected) {
+          connectedPeersCount.innerHTML =
+            '<span>' + this.sync.getNumberOfConnectedPeers() + '</span>'
+          hoverMessage = L._(
+            '{connectedPeers} peer(s) currently connected to this map',
+            {
+              connectedPeers: connectedPeers,
+            }
+          )
+        } else {
+          connectedPeersCount.innerHTML = '<span>' + L._('Disconnected') + '</span>'
+          connectedPeersCount.classList.add('disconnected')
+          hoverMessage = L._('Reconnecting in {seconds} seconds', {
+            seconds: this.sync._reconnectDelay / 1000,
+          })
+        }
+
         L.DomEvent.on(connectedPeersCount, 'mouseover', () => {
           this.tooltip.open({
-          content: L._('{connectedPeers} peer(s) currently connected to this map', {
-            connectedPeers: connectedPeers,
-          }),
+            content: hoverMessage,
             anchor: connectedPeersCount,
             position: 'bottom',
             delay: 500,
             duration: 5000,
           })
         })
-
-      const updateConnectedPeersCount = () => {
-        connectedPeersCount.innerHTML =
-          '<span>' + this.sync.getNumberOfConnectedPeers() + '</span>'
       }
-      updateConnectedPeersCount()
     }
 
     this.help.getStartedLink(rightContainer)

umap/static/umap/js/umap.js

@@ -68,7 +68,14 @@ U.Map = L.Map.extend({
     this.server = new U.ServerRequest()
     this.request = new U.Request()
 
-    this.sync_engine = new U.SyncEngine(this, this.urls, this.server)
+    // Store URIs to avoid persisting the map
+    // mainly to ensure separation of concerns.
+    const websocketTokenURI = this.urls.get('map_websocket_auth_token', {
+      map_id: this.options.umap_id,
+    })
+    const websocketURI = this.options.websocketURI
+
+    this.sync_engine = new U.SyncEngine(this, websocketTokenURI, websocketURI, this.server)
     this.sync = this.sync_engine.proxy(this)
 
     this.initLoader()
@@ -206,7 +213,9 @@ U.Map = L.Map.extend({
   },
 
   initSyncEngine: async function () {
+    // This.options.websocketEnabled is set by the server admin
     if (this.options.websocketEnabled === false) return
+    // This.options.syncEnabled is set by the user in the map settings
     if (this.options.syncEnabled !== true) {
       this.sync.stop()
     } else {

umap/static/umap/map.css

@@ -518,6 +518,12 @@ ul.photon-autocomplete {
     background-color: var(--color-lightCyan);
     color: var(--color-dark);
 }
+.leaflet-container .leaflet-control-connected-peers.disconnected,
+.leaflet-container .leaflet-control-connected-peers.disconnected:hover
+{
+    background-color: var(--color-red);
+    color: var(--color-darkGray);
+}
 
 .leaflet-container .leaflet-control-edit-disable:before,
 .leaflet-container .leaflet-control-edit-save:before,

umap/static/umap/unittests/sync.js

@@ -8,8 +8,11 @@ import { MapUpdater } from '../js/modules/sync/updaters.js'
 import { SyncEngine, Operations } from '../js/modules/sync/engine.js'
 
 describe('SyncEngine', () => {
+  const websocketTokenURI = 'http://localhost:8000/api/v1/maps/1/websocket_auth_token/'
+  const websocketURI = 'ws://localhost:8000/ws/maps/1/'
+
   it('should initialize methods even before start', () => {
-    const engine = new SyncEngine({})
+    const engine = new SyncEngine({}, websocketTokenURI, websocketURI, {})
     engine.upsert()
     engine.update()
     engine.delete()