在具有动态响应形式的值更改中使用验证器来执行测试

例如,我有一个控件,它是一组单选按钮。

• 选择1
• 选择2
• 选择3

如果勾选了choice1或choice2,并且它与我在组件TS中的字段不兼容,那么自定义验证器应该拒绝用户操作并返回到以前的状态和值。

组件.ts

  toFormGroup(properties: PropertyBase<string>[]): FormGroup {
    const group: any = {};
    properties.forEach(property => {
      const validators = this.service.getValidatorsByProperty(property);
      if (property.required) validators.push(Validators.required);
      const formControl = group[property.key] = new FormControl(
        {
          property.value,
          disabled: property.disabled || false
        }
      );
      formControl
      .valueChanges.pipe(takeUntil(/** comp destroyed */))
      .subscribe(val => {
        formControl.setValidators(validators);
        // if validators fail then I reset formControl to its previous state and value
        // else submit the changes
        submit(val);
      });
    });
    return new FormGroup(group);
  }

验证器示例

export function myValidator(
  theFieldINeedForMyCondition: any
): ValidatorFn {
  return (control: AbstractControl): ValidationErrors | null => {
    let forbidden = false;
    if (theFieldINeedForMyCondition)
      forbidden = true;
    return forbidden ? { forbiddenValue: { value: control.value } } : null;
  };
// Maybe reset state and value directly here ?
}

所以问题是:例如,如果我选中了选项2,我可以将选择设置为选项3吗?