feat(h-grid): set expected return field in nested query and select if match

Author: igdmdimitrov

projects/igniteui-angular/src/lib/query-builder/query-builder-tree.component.html

@@ -469,6 +469,7 @@
                         [entities]="(this.selectedEntity ? this.selectedEntity.childEntities : entities[0].childEntities) ?? entities"
                         [queryBuilder]="this.queryBuilder"
                         [parentExpression]="expressionItem"
+                        [expectedReturnField]="this.selectedField?.field"
                         [expressionTree]="expressionItem.inEditMode ? (innerQueryNewExpressionTree ?? getExpressionTreeCopy(expressionItem.expression.searchTree, true)) : expressionItem.expression.searchTree"
                         (inEditModeChange)="onInEditModeChanged($event)"
                         [searchValueTemplate]="searchValueTemplate">

projects/igniteui-angular/src/lib/query-builder/query-builder-tree.component.ts

@@ -242,6 +242,11 @@ export class IgxQueryBuilderTreeComponent implements AfterViewInit, OnDestroy {
         return this._resourceStrings;
     }
 
+    /**
+     * Gets/sets the expected return field.
+     */
+    @Input() public expectedReturnField: string = null;
+
     /**
      * Event fired as the expression tree is changed.
      */
@@ -557,7 +562,7 @@ export class IgxQueryBuilderTreeComponent implements AfterViewInit, OnDestroy {
         this.groupContextMenuDropDownOverlaySettings.outlet = this.overlayOutlet;
 
         if (this.isAdvancedFiltering() && this.entities?.length === 1) {
-            this._selectedEntity = this.entities[0];
+            this.selectedEntity = this.entities[0].name;
         }
 
         // Trigger additional change detection cycle
@@ -629,7 +634,11 @@ export class IgxQueryBuilderTreeComponent implements AfterViewInit, OnDestroy {
         }
         this.fields = this._entityNewValue ? this._entityNewValue.fields : [];
 
-        this._selectedReturnFields = this.parentExpression ? [] : this._entityNewValue.fields?.map(f => f.field);
+        if (this.entities[0].fields.find(f => f.field === this.expectedReturnField)) {
+            this._selectedReturnFields = [this.expectedReturnField];
+        } else {
+            this._selectedReturnFields = this.parentExpression ? [] : this._entityNewValue.fields?.map(f => f.field);
+        }
 
         if (this._expressionTree) {
             this._expressionTree.entity = this._entityNewValue.name;