angular 7 get Parent node value from ngx-treeview

Question

I used angular 7 and ngx-treeview component .

I have used a config of decoupleChildFromParent= true.

From this treeview we only get child tree value. I want to get the parent node value.

this my html code :

  <ng-template #itemTemplate let-item="item" let-onCollapseExpand="onCollapseExpand" let-onCheckedChange="onCheckedChange">
      <div class="form-inline row-item">

        <i *ngIf="item.children" (click)="onCollapseExpand()" aria-hidden="true" class="fa" [class.fa-caret-right]="item.collapsed"
          [class.fa-caret-down]="!item.collapsed"></i>
        <div class="form-check">
          <input type="checkbox" class="form-check-input" [(ngModel)]="item.checked" (ngModelChange)="onCheckedChange()" [disabled]="item.disabled"
            [indeterminate]="item.indeterminate" />
          <label class="form-check-label" (click)="item.checked = !item.checked; onCheckedChange()">
            {{item.text}}
          </label>

        </div>
      </div>
    </ng-template>

    <div class="row">
      <div class="col-6">
        <div class="form-group">
          <div class="d-inline-block">
            <ngx-treeview [items]="items" [itemTemplate]="itemTemplate" (selectedChange)="onSelectedChange($event)">
            </ngx-treeview>
          </div>
        </div>
      </div>

    </div>

I used onSelectedChange function with this code :

 onSelectedChange(downlineItems: DownlineTreeviewItem[]) {
            this.rows = [];
            downlineItems.forEach(downlineItem => {
                const item = downlineItem.item;
                const value = item.value;
                const texts = [item.text];
                let parent = downlineItem.parent
                while (!isNil(parent)) {
                    texts.push(parent.item.text);
                    parent = parent.parent;
                }
                const reverseTexts = reverse(texts);
                const row = `${reverseTexts.join(' -> ')} : ${value}`;
                this.rows.push(row);
                this.rowsSelect=value;
            });
        }

when I check the parent check box, selectedChange event fired with empty array of values.

I would like to retrieve the value of selected parent when none of the child is selected

Answer 1

import {TreeviewHelper} from 'ngx-treeview';

TreeviewHelper.findParent(rootItem, item);