Angular Form内置验证器错误对象键

Question

Where can I get the the error object keys list of the built-in Validators ?

For example, if a field uses the required built-in validator, then I can check:

form.get('myField').hasError('required')

but not all the error object keys have the same name as the validator.

For example, if I use the maxLength validator, then the following will not work:

form.get('myField').hasError('maxLength')

Answer 1

It is possible to check those values looking directly at the source code:

https://github.com/angular/angular/blob/master/packages/forms/src/validators.ts

---

In my specific case, the object key error for the maxLength validator is maxlength (with lower case L).

I figured it out by looking its implementation in the source code, currently:

  static maxLength(maxLength: number): ValidatorFn {
    return (control: AbstractControl): ValidationErrors | null => {
      const length: number = control.value ? control.value.length : 0;
      return length > maxLength ?
          {'maxlength': {'requiredLength': maxLength, 'actualLength': length}} :
          null;
    };
  }

so I'm using:

form.get('myField').hasError('maxlength')