Alex/fixforqueryrefresh (#9032)

* added some checks

* Added return undefined

* added handling for multiple loads

* added more error handling

* minor space change

* added explanation message

* simplification

* added changes from create new row

* added some checks

* Added return undefined

* added handling for multiple loads

* added more error handling

* minor space change

* added explanation message

* simplification

* editDataGridPanel corrected

* updated to most recent master version

* removed space at end

* added newline

* added another try catch

* changed message

* added check and message

* added clarifying message

* removed redundant try catch loop

* grid data is now backed up

* wording change

src/sql/workbench/contrib/editData/browser/editDataGridPanel.ts

@@ -54,6 +54,7 @@ export class EditDataGridPanel extends GridParentComponent {
 	//main dataset to work on.
 	private dataSet: IGridDataSet;
 	private oldDataRows: VirtualizedCollection<any>;
+	private oldGridData: {}[];
 	private firstRender = true;
 	private firstLoad = true;
 	private enableEditing = true;
@@ -158,6 +159,7 @@ export class EditDataGridPanel extends GridParentComponent {
 	handleStart(self: EditDataGridPanel, event: any): void {
 		self.dataSet = undefined;
 		self.oldDataRows = undefined;
+		self.oldGridData = undefined;
 		self.placeHolderDataSets = [];
 		self.renderedDataSets = self.placeHolderDataSets;
 
@@ -220,6 +222,7 @@ export class EditDataGridPanel extends GridParentComponent {
 		// Setup a function for generating a promise to lookup result subsets
 		this.loadDataFunction = (offset: number, count: number): Promise<{}[]> => {
 			return self.dataService.getEditRows(offset, count).then(result => {
+				if (this.dataSet) {
 					let gridData = result.subset.map(r => {
 						let dataWithSchema = {};
 						// skip the first column since its a number column
@@ -242,8 +245,15 @@ export class EditDataGridPanel extends GridParentComponent {
 							return p;
 						}, {}));
 					}
-
+					if (gridData && gridData !== this.oldGridData) {
+						this.oldGridData = gridData;
+					}
 					return gridData;
+				}
+				else {
+					this.logService.error('Grid data is nonexistent, using last known good grid');
+					return this.oldGridData;
+				}
 			});
 		};
 	}
@@ -431,17 +441,22 @@ export class EditDataGridPanel extends GridParentComponent {
 			clearTimeout(this.refreshGridTimeoutHandle);
 
 			this.refreshGridTimeoutHandle = setTimeout(() => {
-
+				try {
 					if (this.dataSet) {
 						this.placeHolderDataSets[0].dataRows = this.dataSet.dataRows;
 						this.onResize();
 					}
 
 
-				if (this.oldDataRows !== this.placeHolderDataSets[0].dataRows) {
+					if (this.placeHolderDataSets[0].dataRows && this.oldDataRows !== this.placeHolderDataSets[0].dataRows) {
 						this.detectChange();
 						this.oldDataRows = this.placeHolderDataSets[0].dataRows;
 					}
+				}
+				catch {
+					this.logService.error('data set is empty, refresh cancelled.');
+					reject();
+				}
 
 				if (this.firstRender) {
 					setTimeout(() => this.setActive());
@@ -583,8 +598,11 @@ export class EditDataGridPanel extends GridParentComponent {
 	// Checks if input row is our NULL new row
 	private isNullRow(row: number): boolean {
 		// Null row is always at index (totalRows - 1)
+		if (this.dataSet) {
 			return (row === this.dataSet.totalRows - 1);
 		}
+		return false;
+	}
 
 	// Adds CSS classes to slickgrid cells to indicate a dirty state
 	private setCellDirtyState(row: number, column: number, dirtyState: boolean): void {