Angular 15 Reactive Forms Validation Tutorial Example

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This article is focused on angular 15 reactive forms validation. If you have a question about angular 15 forms validation example then I will give a simple example with a solution. I’m going to show you about angular 15 reactive forms example. This tutorial will give you a simple example of reactive form validation in angular 15. Alright, let’s dive into the details.

Reactive forms provide a model-driven approach to handling form inputs whose values change over time. In Reactive forms, we need to import "ReactiveFormsModule" from the angular forms library. we will use FormControl, FormGroup, FormArray, and Validation classes with Reactive forms in the angular 15 apps.

If you have simple and basic forms in your angular 15 application then I will prefer to use Reactive forms in angular. here I write a simple example of Reactive forms with validation in angular 15.

You need to follow the below steps to create reactive forms in angular 15.

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 15 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. therefore, 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. therefore, 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 15.

src/app/app.component.html

<h1>Angular 15 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. therefore, 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...