Disable Input fields in reactive form

Question

I already tried to follow the example of other answers from here and I did not succeed!

I created a reactive form (ie, dynamic) and I want to disable some fields at any given time. My form code:

this.form = this._fb.group({
  name: ['', Validators.required],
  options: this._fb.array([])
});

const control = <FormArray>this.form.controls['options'];
control.push(this._fb.group({
  value: ['']
}));

my html:

<div class='row' formArrayName="options">
  <div *ngFor="let opt of form.controls.options.controls; let i=index">
    <div [formGroupName]="i">
      <select formArrayName="value">
        <option></option>
        <option>{{ opt.controls.value }}</option>
      </select>
    </div>
  </div>
</div>

I reduced the code to facilitate. I want to disable the field of type select. I tried to do the following:

form = new FormGroup({
  first: new FormControl({value: '', disabled: true}, Validators.required),
});

not working! Does anyone have a suggestion?

Answer 1

The best solution is here:

https://netbasal.com/disabling-form-controls-when-working-with-reactive-forms-in-angular-549dd7b42110

Outline of solution (in case of broken link):

(1) Create a directive

import { NgControl } from '@angular/forms';

@Directive({selector: '[disableControl]'})
export class DisableControlDirective {

  @Input() set disableControl( condition : boolean ) {
    const action = condition ? 'disable' : 'enable';
    this.ngControl.control[action]();
  }

  constructor( private ngControl : NgControl ) {}
}

(2) Use it like so

<input [formControl]="formControl" [disableControl]="condition">

(3) Since disabled inputs do not show in form.value on submit you may need to use the following instead (if required):

onSubmit(form) {
  const formValue = form.getRawValue() // gets form.value including disabled controls
  console.log(formValue)
}

Answer 2

If to use disabled form input elements (like suggested in correct answer how to disable input) validation for them will be also disabled, take attention for that!

(And if you are using on submit button like [disabled]="!form.valid"it will exclude your field from validation)

Answer 3

Pay attention

If you are creating a form using a variable for condition and trying to change it later it will not work, i.e. the form will not change.

For example

this.isDisabled = true;

this.cardForm = this.fb.group({
    'number': [{value: null, disabled: this.isDisabled},
});

and if you change the variable

this.isDisabled = false;

the form will not change. You should use

this.cardForm.get('number').disable();

BTW.

You should use patchValue method for changing value:

this.cardForm.patchValue({
    'number': '1703'
});

Answer 4

To make a field disable and enable of reactive form angular 2+

1.To disable

• Add [attr.disabled]="true" to input.

<input class="form-control" name="Firstname" formControlName="firstname" [attr.disabled]="true">

To enable

export class InformationSectionComponent {
formname = this.formbuilder.group({
firstname: ['']
});
}

Enable whole form

this.formname.enable();

Enable particular field alone

this.formname.controls.firstname.enable();

same for disable, replace enable() with disable().

This Works fine. Comment for queries.

Answer 5

The disabling FormControl prevents it to be present in a form while saving. You can just set it the readonly property.

Answer 6

lastName: new FormControl({value: '', disabled: true}, Validators.compose([Validators.required])),