Unregister notification handlers.

When leaving the Project component, all its notification handlers
will be unregistered, otherwise we end up with a memory leak.

lib/www/client/source/src/views/Project.vue

@@ -85,10 +85,10 @@ export default {
       this.refreshSequences();
     },
 
-    registerNotificationHandlers () {
+    registerNotificationHandlers (action = "registerHandler") {
 
 
-      this.$store.dispatch('registerHandler', {
+      this.$store.dispatch(action, {
         table: 'event',
 
         handler: (context, message) => {
@@ -97,7 +97,7 @@ export default {
       });
 
       ["preplot_lines", "preplot_points"].forEach( table => {
-        this.$store.dispatch('registerHandler', {
+        this.$store.dispatch(action, {
           table,
 
           handler: (context, message) => {
@@ -107,7 +107,7 @@ export default {
       });
 
 
-      this.$store.dispatch('registerHandler', {
+      this.$store.dispatch(action, {
         table: 'planned_lines',
 
         handler: (context, message) => {
@@ -116,7 +116,7 @@ export default {
       });
 
       ["raw_lines", "raw_shots", "final_lines", "final_shots"].forEach( table => {
-        this.$store.dispatch('registerHandler', {
+        this.$store.dispatch(action, {
           table,
 
           handler: (context, message) => {
@@ -127,6 +127,10 @@ export default {
 
     },
 
+    unregisterNotificationHandlers () {
+      return this.registerNotificationHandlers("unregisterHandler");
+    },
+
     ...mapActions(["getProject", "refreshLines", "refreshSequences", "refreshEvents", "refreshLabels", "refreshPlan"])
   },
 
@@ -141,7 +145,12 @@ export default {
       this.refreshLabels();
       this.refreshPlan();
     }
+  },
+
+  beforeDestroy () {
+    this.unregisterNotificationHandlers();
   }
 
+
 }
 </script>