client: Display errors for right panel widgets instead of crashing

src/public/app/widgets/right_panel_widget.js

@@ -1,4 +1,6 @@
 import NoteContextAwareWidget from "./note_context_aware_widget.js";
+import toastService from "../services/toast.js";
+import { t } from "../services/i18n.js";
 
 const WIDGET_TPL = `
 <div class="card widget">
@@ -54,7 +56,19 @@ class RightPanelWidget extends NoteContextAwareWidget {
             this.$buttons.append(buttonWidget.render());
         }
 
-        this.initialized = this.doRenderBody();
+        try {
+            this.initialized = this.doRenderBody();
+        } catch (e) {
+            toastService.showPersistent({
+                title: t("toast.widget-error.title"),
+                icon: "alert",
+                message: t("toast.widget-error.message", {
+                    title: this.widgetTitle,
+                    message: e.message
+                })
+            });
+            logError(e);
+        }
     }
 
     /**

src/public/translations/en/translation.json

@@ -13,6 +13,10 @@
     "critical-error": {
       "title": "Critical error",
       "message": "A critical error has occurred which prevents the client application from starting:\n\n{{message}}\n\nThis is most likely caused by a script failing in an unexpected way. Try starting the application in safe mode and addressing the issue."
+    },
+    "widget-error": {
+      "title": "Failed to initialize a widget",
+      "message": "Widget with title \"{{title}}\" could not be initialized due to:\n\n{{message}}"
     }
   }
 }