Fix empty form path source on edit

Author: godind

src/app/widget-config/dataset-chart-options/dataset-chart-options.component.ts

@@ -142,7 +142,11 @@ export class DatasetChartOptionsComponent implements OnInit {
       this.datachartSource().enable();
     } else if (Object.keys(pathObject.sources).length > 1) {
       this.pathSources.set(Object.keys(pathObject.sources).sort());
-      this.datachartSource().reset();
+      if(this.datachartSource().value) {
+        this.datachartSource().setValue(this.datachartSource().value);
+      } else {
+        this.datachartSource().reset();
+      }
       this.datachartSource().enable();
     }
   }

src/app/widgets/widget-data-chart/widget-data-chart.component.ts

@@ -105,12 +105,15 @@ export class WidgetDataChartComponent implements AfterViewInit, OnDestroy {
     // Effect: react to Dataset config changes
     effect(() => {
       const sig = this.pathSignature();
-      if (sig !== this.previousPathSignature) {
-        untracked(() => {
-        this.previousPathSignature = sig;
-        this.rebuildForDataset(this.runtime.options());
-        });
-      }
+
+      untracked(() => {
+        if (sig !== this.previousPathSignature) {
+          untracked(() => {
+          this.previousPathSignature = sig;
+          this.rebuildForDataset(this.runtime.options());
+          });
+        }
+      });
     });
 
     // Effect: react to Display config or theme changes