formGroup.get vs formGroup.controls in reactive fo

问题:

Is there any preferred way when selecting validation using

• myForm.controls['name'].valid
• myForm.get('name').valid

as both seems to be only syntactically different but achieving the same goal.

<label>Name
  <input type="text" formControlName="name">
</label>
<div class="alert" *ngIf="!myForm.controls['name'].valid && myForm.controls['name'].touched">
  {{ titleAlert }}
</div>

Same as

<div class="alert" *ngIf="!myForm.get('name').valid && myForm.get('name').touched">
  {{ titleAlert }}
</div>

From what I checked in the code, get has this code:

AbstractControl.prototype.get = function (path) { return _find(this, path, '.'); };

I have just started Angular, so an expert opinion would be appreciated.

回答1:

Just like what you have found, FormGroup.get is designed to access target formcontrol by it's path. And it's more often used for complicated(multi layer embed) situation, which makes it easy to get the target control from multi layer embed form and also makes code clear and easily to understand.

Take below as a example, you can simply access the first element of the embed FormArray by this.form.get('test.0') instead of this.form.controls.test.controls[0]:

this.form = this.formBuilder.group(
  {
    test: this.formBuilder.array(
      [
        ['form control 1 in form array'],
        ['form control 1 in form array'],
        ...
      ]
    )
  }
);