Fix some legacy parent issues where parent DOM node was not found when needed

- Checking & waiting for promises
- Could not get DOM nodes from nm header sub-templates

api/js/etemplate/Et2Widget/Et2Widget.ts

@@ -603,7 +603,11 @@ const Et2WidgetMixin = (superClass) =>
 		 *
 		 * @param {Promise[]} promises List of promises from widgets that are not done.  Pass an empty array, it will be filled if needed.
 		 */
-		loadingFinished(promises)
+		loadingFinished(promises : Promise<any>[])
+		{
+			// Note that WebComponents don't do anything here, their lifecycle is different
+			// This is just to support legacy widgets
+			let doLoadingFinished = () =>
 			{
 				/**
 				 * This is needed mostly as a bridge between non-WebComponent widgets and
@@ -629,6 +633,12 @@ const Et2WidgetMixin = (superClass) =>
 
 					child.loadingFinished(promises);
 				}
+			};
+			if(typeof promises === "undefined")
+			{
+				return doLoadingFinished();
+			}
+			Promise.all(promises).then(doLoadingFinished);
 		}
 
 		getWidgetById(_id)

api/js/etemplate/et2_extension_nextmatch.ts

@@ -3848,14 +3848,31 @@ export class et2_nextmatch_header_bar extends et2_DOMWidget implements et2_INext
 				return this.filter_div[0];
 			}
 		}
-		if(_sender == this.et2_searchbox) return this.search_box[0];
-		if(_sender.id == 'export') return this.right_div[0];
+		if(_sender == this.et2_searchbox)
+		{
+			return this.search_box[0];
+		}
+		if(_sender.id == 'export')
+		{
+			return this.right_div[0];
+		}
 
 		if(_sender && _sender._type == "template")
 		{
 			for(let i = 0; i < this.headers.length; i++)
 			{
-				if(_sender.id == this.headers[i].id && _sender._parent == this) return i == 2 ? this.header_row[0] : this.header_div[0];
+				if(_sender.id == this.headers[i].id && _sender._parent == this)
+				{
+					return i == 2 ? this.header_row[0] : this.header_div[0];
+				}
+			}
+		}
+
+		for(let header of this.headers)
+		{
+			if(header && header.getDOMNode && header.getDOMNode(this))
+			{
+				return header.getDOMNode(this);
 			}
 		}
 		return null;

api/js/etemplate/et2_widget_grid.ts

@@ -945,6 +945,7 @@ export class et2_grid extends et2_DOMWidget implements et2_IDetachedDOM, et2_IAl
 			const cell = this.managementArray[i];
 			if(cell.widget)
 			{
+				this.removeChild(cell.widget);
 				cell.widget.destroy();
 			}
 		}