Angular Form Validation no Whitespace Allowed Example

By Hardik Savani | December 20, 2019 | Category : Angular


Sometime we need to add validation for no space allow on input field. so here i will give you example of How to validate Whitespace / spaces in angular applicarion?, you can easily use custom validation for Angular No Whitespace Allowed Vaidator for reactive form.

You can easily use this custom validation for no space allowed with angular 6, angular 7, angular 8, angular 9 and angular 10.

Actually, few days ago i was working on my reactive form and i need to add custom validation for not allow white space. i thought i will use something if condition or anything else. but i found way to create custom validation for rules for this. so i created very simple way for no space allow to input field in angular application.

We will create new custom validator for not contain space on input field. we will not allow space on username. so let's see now it works

Step 1: Install Angular App

Here, in this step you need to create new ng app for this demo. if you have already created then don't create new angular 8 app.

ng new my-custom-val-app

Step 2: Import FormsModule

If you want to create form in angular app then you need to import FormsModule from @angular/forms library. so let's add following code to app.module.ts file.

src/app/app.module.ts

import { BrowserModule } from '@angular/platform-browser';

import { NgModule } from '@angular/core';

import { FormsModule, ReactiveFormsModule } from '@angular/forms';

import { AppComponent } from './app.component';

@NgModule({

declarations: [

AppComponent

],

imports: [

BrowserModule,

FormsModule,

ReactiveFormsModule

],

providers: [],

bootstrap: [AppComponent]

})

export class AppModule { }

Step 3: Form with ngModel

In this step, we will write code of html form with ngModel. so add following code to app.component.html file.

I used bootstrap class on this form. if you want to add than then follow this link too: Install Boorstrap 4 to Angular 8.

src/app/app.component.html

<h1>How to Create Custom Validators in Angular 8 - ItSolutionStuff.com</h1>

<form [formGroup]="form" (ngSubmit)="submit()">

<div class="form-group">

<label for="username">Username</label>

<input

formControlName="username"

id="username"

type="text"

class="form-control">

<div *ngIf="f.username.touched && f.username.invalid" class="alert alert-danger">

<div *ngIf="f.username.errors.required">Username is required.</div>

<div *ngIf="f.username.errors.minlength">Username should be 3 character.</div>

<div *ngIf="f.username.errors.cannotContainSpace">Username can not contain space.</div>

</div>

</div>

<div class="form-group">

<label for="password">Password</label>

<input

formControlName="password"

id="password"

type="password"

class="form-control">

<div *ngIf="f.password.touched && f.password.invalid" class="alert alert-danger">

<div *ngIf="f.password.errors.required">Password is required.</div>

</div>

</div>

<button class="btn btn-primary" type="submit">Submit</button>

</form>

Step 4: updated Ts File

In ts file. we will write submit() and get all input fields values. so let's add following code to app.component.ts file.

src/app/app.component.ts

import { Component } from '@angular/core';

import { FormGroup, FormControl, Validators} from '@angular/forms';

import { UsernameValidator } from './username.validator';

@Component({

selector: 'app-root',

templateUrl: './app.component.html',

styleUrls: ['./app.component.css']

})

export class AppComponent {

form = new FormGroup({

username: new FormControl('', [Validators.required, Validators.minLength(3), UsernameValidator.cannotContainSpace]),

password: new FormControl('', Validators.required)

});

get f(){

return this.form.controls;

}

submit(){

console.log(this.form.value);

}

}

Step 5: Create Custom Validation File

You need to create custom 'username.validator.ts' file and write code as bellow:

src/app/username.validator.ts

import { AbstractControl, ValidationErrors } from '@angular/forms';

export class UsernameValidator {

static cannotContainSpace(control: AbstractControl) : ValidationErrors | null {

if((control.value as string).indexOf(' ') >= 0){

return {cannotContainSpace: true}

}

return null;

}

}

Now you can run your application using following command:

ng serve

Now you can see layout as like bellow screen shot:

I hope it can help you...




Hardik Savani
My name is Hardik Savani. I'm a full-stack developer, entrepreneur and owner of Aatman Infotech. I live in India and I love to write tutorials and tips that can help to other artisan. I am a big fan of PHP, Javascript, JQuery, Laravel, Codeigniter, VueJS, AngularJS and Bootstrap from the early stage.
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