Method ngOnChanges

packages/forms/src/directives/ng_model.ts:257–281

@docs-private

(changes: SimpleChanges)

  /** @docs-private */
  ngOnChanges(changes: SimpleChanges) {
    this._checkForErrors();
    if (!this._registered || 'name' in changes) {
      if (this._registered) {
        this._checkName();
        if (this.formDirective) {
          // We can't call `formDirective.removeControl(this)`, because the `name` has already been
          // changed. We also can't reset the name temporarily since the logic in `removeControl`
          // is inside a promise and it won't run immediately. We work around it by giving it an
          // object with the same shape instead.
          const oldName = changes['name'].previousValue;
          this.formDirective.removeControl({name: oldName, path: this._getPath(oldName)});
        }
      }
      this._setUpControl();
    }
    if ('isDisabled' in changes) {
      this._updateDisabled(changes);
    }

    if (isPropertyUpdated(changes, this.viewModel)) {
      this._updateValue(this.model);
      this.viewModel = this.model;
    }
  }

  /** @docs-private */
  ngOnDestroy(): void {