Method addChild

src/cdk/tree/tree-with-tree-control.spec.ts:1316–1333

(parent: TestData, isFlat: boolean = true)

  }

  addChild(parent: TestData, isFlat: boolean = true) {
    const nextIndex = ++this.dataIndex;
    const child = new TestData(
      `topping_${nextIndex}`,
      `cheese_${nextIndex}`,
      `base_${nextIndex}`,
      parent.level + 1,
    );
    parent.children.push(child);
    if (isFlat) {
      let copiedData = this.data.slice();
      copiedData.splice(this.data.indexOf(parent) + 1, 0, child);
      this.data = copiedData;
    } else {
      parent.observableChildren.next(parent.children);
    }
    return child;
  }

  addData(level: number = 1) {
    const nextIndex = ++this.dataIndex;