Angular 13 Reactive Forms Validation Tutorial Example

Hi,

Today, i will let you know example of angular 13 reactive forms validation. you can understand a concept of angular 13 forms validation example. if you have question about angular 13 reactive forms example then i will give simple example with solution. you can understand a concept of reactive form validation in angular 13. Here, Creating a basic example of angular 13 form validation example.

Reactive forms provide a model-driven approach to handling form inputs whose values change over the time. In Reactive forms, we need to import "ReactiveFormsModule" from angular forms library. we will use FormControl, FormGroup, FormArray, Validation classes with Reactive forms in angular 13 app.

If you have simple and basic form in your angular 13 application then i will prefer to use Reactive forms in angular. here i write simple example of Reactive forms with validation in angular 13.

You need to follow bellow step to create reactive forms in angular 13.

Preview:

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 13 app.

ng new my-new-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 { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
  
import { AppComponent } from './app.component';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
  
@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 Bootstrap 5 to Angular 13.

src/app/app.component.html

<h1>Angular 13 Reactive Forms Validation Example - ItSolutionStuff.com</h1>
    
<form [formGroup]="form" (ngSubmit)="submit()">
        
    <div class="form-group">
        <label for="name">Name</label>
        <input 
            formControlName="name"
            id="name" 
            type="text" 
            class="form-control">
        <div *ngIf="f['name'].touched && f['name'].invalid" class="alert alert-danger">
            <div *ngIf="f['name'].errors && f['name'].errors['required']">Name is required.</div>
            <div *ngIf="f['name'].errors && f['name'].errors['minlength']">Name should be 3 character.</div>
        </div>
    </div>
     
    <div class="form-group">
        <label for="email">Email</label>
        <input 
            formControlName="email"
            id="email" 
            type="text" 
            class="form-control">
        <div *ngIf="f['email'].touched && f['email'].invalid" class="alert alert-danger">
            <div *ngIf="f['email'].errors && f['email'].errors['required']">Email is required.</div>
            <div *ngIf="f['email'].errors && f['email'].errors['email']">Please, enter valid email address.</div>
        </div>
    </div>
     
    <div class="form-group">
        <label for="body">Body</label>
        <textarea 
            formControlName="body"
            id="body" 
            type="text" 
            class="form-control">
        </textarea>
        <div *ngIf="f['body'].touched && f['body'].invalid" class="alert alert-danger">
            <div *ngIf="f['body'].errors && f['body'].errors['required']">Body is required.</div>
        </div>
    </div>
    
    <button class="btn btn-primary" [disabled]="form.invalid" 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';
  
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  
  form = new FormGroup({
    name: new FormControl('', [Validators.required, Validators.minLength(3)]),
    email: new FormControl('', [Validators.required, Validators.email]),
    body: new FormControl('', Validators.required)
  });
  
  get f(){
    return this.form.controls;
  }
  
  submit(){
    console.log(this.form.value);
  }
  
}

Run Angular App:

All the required steps have been done, now you have to type the given below command and hit enter to run the Angular app:

ng serve

Now, Go to your web browser, type the given URL and view the app output:

http://localhost:4200

Output

{name: "Hardik Savani", email: "itsolutionstuff@gmail.com", body: "This is a test"}

I hope it can help you...