chore(*): Extract key from tree grid record.

Author: MKirova

projects/igniteui-angular/src/lib/grids/row.directive.ts

@@ -629,7 +629,7 @@ export class IgxRowDirective implements DoCheck, AfterViewInit, OnDestroy {
             const isPinned = this.pinned && !this.disabled;
             const indexInData = this.grid.isRowPinningToTop && !isPinned ? this.index - this.grid.pinnedRecordsCount : this.index;
             const range = isPinned ? this.grid.pinnedDataView.slice(indexInData, indexInData + rowCount) : this.grid.verticalScrollContainer.igxForOf.slice(indexInData, indexInData + rowCount);
-            const inRange = range.filter(x => this.selectionService.isRowSelected(this.grid.primaryKey ? (x.recordRef || x)[this.grid.primaryKey] : (x.recordRef || x))).length > 0;
+            const inRange = range.filter(x => this.selectionService.isRowSelected(this.extractRecordKey(x))).length > 0;
             return inRange;
         }
         return false;
@@ -646,6 +646,18 @@ export class IgxRowDirective implements DoCheck, AfterViewInit, OnDestroy {
         return false;
     }
 
+    protected extractRecordKey(rec: any) {
+        let recData = rec;
+        if (this.grid.isRecordMerged(recData)) {
+            recData = rec.recordRef;
+        }
+
+        if(this.grid.isTreeRow && this.grid.isTreeRow(recData)){
+            recData = recData.data;
+        }
+        return this.grid.primaryKey ? recData[this.grid.primaryKey] : recData;
+    }
+
     protected getRowHeight() {
         const indexInData  = this.grid.verticalScrollContainer.igxForOf.indexOf(this.metaData);
         const size = this.grid.verticalScrollContainer.getSizeAt(indexInData) - 1;