Angular: get list of all validators from a FormControl

Question

I might be wrong here, but after a bit of research it seems impossible to extract the list of validators from a FormControl

const ctrl = new FormControl(null,[Validators.minLength(8), Validators.required]});

I would like a list with these validators, so I can do something like this (in theory)

const validators = ctrl.getValidators();
ctrl.setValidators( [...validators, myOwnValidator]);

Ideally I would like to append a validator, but as far as I know that is not possible.

I found two suggestions on the internet to access the validators on a FormControl:

1)

const validator = ctrl.validator('' as any as AbstractControl);
// -> {required: true}

const validator = ctrl.validator({} as AbstractControl); // -> {required: true}

Both options do exactly the same thing, they return an object with just one key required and a value true. Not very useful because I don't see anything about the other validator and I need the validator classes (because I need to set the validators again).

What I have found so far is not very useful, so I was wondering if I missed something. So any help would be appreciated!

you mean that validators const? Because I need to add another validator, so I need all the existing ones. — Jeanluca Scaljeri
– Jeanluca Scaljeri, Commented Sep 24, 2021 at 10:58
Could you tell me what's the goal ? What you want to do on your formControl now or in the future ? — marcant0
– marcant0, Commented Sep 24, 2021 at 11:01

shutsman · Accepted Answer · 2021-09-24 11:30:16Z

2

Solution for Angular 12.2.0

this.form.controls["firstName"].addValidators([Validators.minLength(1), Validators.maxLength(30)]);

Solution for angular 11 and below

you can define validators for specific control into variable and then reuse it

public ctrlDefaultValidators = [Validators.minLength(8), Validators.required];
public ctrl = new FormControl(null, ctrlDefaultValidators});

ctrl.setValidators( [...ctrlDefaultValidators , myOwnValidator]);

ps: dont forget to call updateValueAndValidity

edited Sep 24, 2021 at 11:30

answered Sep 24, 2021 at 10:50

shutsman

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4 Comments

Jeanluca Scaljeri Over a year ago

Do you have a link to the angular documentation, because I can't find anything about addValidators

shutsman Over a year ago

sorry, it is not present in your version, it is added in v12.2.0. github.com/angular/angular/blob/master/…

shutsman Over a year ago

you can try it here stackblitz.com/edit/angular-chap12-l11

Bertramp Over a year ago

@shutsman Please create an answer for all the future poor lost souls working on Angular versions older than 12.2

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