(core) Preventing updates for widgets options when nothing has changed

Summary:
Custom widget was reseving its options, even though they haven't been changed. This
resulted with an ACL error and a popup message in readonly mode.

Test Plan:
Existing and manual.
To recreate:
1. Create a page with a calendar widget (don't change anything)
2. View this page as a Viewer (using ACL dropdown in tools)
3. The error should be shown.

Reviewers: georgegevoian

Reviewed By: georgegevoian

Subscribers: georgegevoian

Differential Revision: https://phab.getgrist.com/D4060

app/client/components/CustomCalendarView.ts

@@ -2,21 +2,36 @@ import {AccessLevel} from "app/common/CustomWidget";
 import {ViewSectionRec} from "app/client/models/entities/ViewSectionRec";
 import {CustomView} from "app/client/components/CustomView";
 import {GristDoc} from "app/client/components/GristDoc";
+import {reportError} from 'app/client/models/errors';
 
 //Abstract class for more future inheritances
 abstract class CustomAttachedView extends CustomView {
   public override create(gristDoc: GristDoc, viewSectionModel: ViewSectionRec) {
     super.create(gristDoc, viewSectionModel);
-    void viewSectionModel.customDef.access.setAndSave(AccessLevel.full);
+    if (viewSectionModel.customDef.access.peek() !== AccessLevel.full) {
+      void viewSectionModel.customDef.access.setAndSave(AccessLevel.full).catch((err)=>{
+        if (err?.code === "ACL_DENY") {
+          // do nothing, we might be in a readonly mode.
+          return;
+        }
+        reportError(err);
+      });
+    }
 
     const widgetsApi = this.gristDoc.app.topAppModel.api;
     widgetsApi.getWidgets().then(async result=>{
       const widget = result.find(w=>w.name == this.getWidgetName());
-      if(widget) {
+      if (widget && this.customDef.url.peek() !== widget.url) {
         await this.customDef.url.setAndSave(widget.url);
       }
-    }).catch(()=>{
-      //do nothing
+    }).catch((err)=>{
+      if (err?.code !== "ACL_DENY") {
+        // TODO: revisit it later. getWidgets() is async call, and non of the code
+        // above is checking if we are still alive.
+        console.error(err);
+      } else {
+        // do nothing, we might be in a readonly mode.
+      }
     });
   }