custom validation input type number angular 2

Question

I would like to know how to set a min and max number in angular2 when we try to limit an input text it's very simple we have to put any ideas about limiting the number for exemple 3 numbers

it work perfect on type text but with number I think we have to do a directive

If you are using Validators class to perform validation, you will need to write custom validators. Pleast post more code so I can see the way you perform validation. — Stefan Svrkota
– Stefan Svrkota, Commented Aug 29, 2016 at 13:09
<input type="number" [(ngModel)]="myvar" name="name" minLength="0" maxLength="4" required /> — imtah
– imtah, Commented Aug 29, 2016 at 13:26
You didn't post enough code, I wouldn't have time to look through it anyway, but this link was very useful to me, I also needed to do same thing you want to do: coryrylan.com/blog/… — Stefan Svrkota
– Stefan Svrkota, Commented Aug 29, 2016 at 13:36

Jérémy Melchor · Accepted Answer · 2016-08-29 19:46:09Z

5

Angular provide some Validators like required,maxLength.. but you can create your own Validator like this :

Create a fonction (this one take your control value, check if it's between 0 and 100. If it's okay, it returns null, which means no problems, otherwise you return an object with valid to false)

function validateNumber(c: FormControl) {
  return c.value > 0 && c.value < 100 ? null : {valid: false}
};

Put your function as a Validator in your control : new FormControl('', validateNumber)

edited Aug 29, 2016 at 19:46

answered Aug 29, 2016 at 14:13

Jérémy Melchor

1692 silver badges7 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

imtah Over a year ago

the min="1" max="100" doesn't work, if I put 100000 for exemple

Jérémy Melchor Over a year ago

I've updated my answer, it's more related to your question i think

Dudi Over a year ago

Great. works perfect. if you want to add validation without deleting any exsiting one, use this: _fc.setValidations(validateNumber); (_fc is a FormControl).

vanessa · Accepted Answer · 2017-10-20 15:16:35Z

You also can create some directives to manage your validator.

HTML :

<input type="number" maxNumber="999"[(ngModel)]="element.orderItemNewCredit" #newCredit="ngModel">
<div *ngIf="newCredit.errors && (newCredit.dirty || newCredit.touched)" class="alert alert-danger">
    <div [hidden]="!newCredit.errors.maxNumber">New credit cannot be superior than 999/div>
</div>

Directive : maxNumberValidator.directive.ts

import {Directive, Input} from '@angular/core';
import {AbstractControl, NG_VALIDATORS, ValidationErrors, Validator} from "@angular/forms";

@Directive({
    selector: '[maxNumber]',
    providers: [{provide: NG_VALIDATORS, useExisting: MaxNumberValidatorDirective, multi: true}]
})

export class MaxNumberValidatorDirective implements Validator {
    @Input() maxNumber: number;

    constructor() { }

    validate(control: AbstractControl): ValidationErrors {
        return control.value <= this.maxNumber ? null : { maxNumber: { valid: false } };
    }
}

And do not forget to add this directive into your module file.

Collectives™ on Stack Overflow

custom validation input type number angular 2

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related