Template-Driven Form Validation in Angular 10

This article will give you example of template-driven form validation in angular 10. this example will help you angular 10 template-driven forms. Here you will learn angular 10 form validation on submit. We will use template driven form in angular 10 example. You just need to some step to done template driven form validation.

You just need to some step to done template driven form in angular 10 example.

Angular 10 provide forms and they provide way to handle user input using ngModel, ngSubmit. Angular 10 provide Template-driven froms and using Template Driven Forms you can create very simple and basic level form.

If you have simple and basic form in your angular 10 application then i will prefer to use Template Driven Forms in angular. here i write simple example of Template Driven Forms with validation in angular 10.

You need to follow bellow step to create template driven form in angular 10.

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 10 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 { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
   
import { AppComponent } from './app.component';
   
@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    FormsModule
  ],
  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 10.

src/app/app.component.html

<h1>Template Driven Forms Validation in Angular 10 Example - HDTuto.com</h1>
   
<form #contactForm="ngForm" (ngSubmit)="submit(contactForm.value)">
   
  <div class="form-group">
      <label for="firstName">First Name</label>
      <input required minlength="3" maxlength="10" ngModel name="firstName" type="text" #firstName="ngModel" class="form-control" id="firstName">
      <div class="alert alert-danger" *ngIf="firstName.touched && !firstName.valid">
          <div *ngIf="firstName.errors.required">First Name is required.</div>
          <div *ngIf="firstName.errors.minlength">First Name is minimum {{ firstName.errors.minlength.requiredLength }} character.</div>
          <div *ngIf="firstName.errors.maxlength">First Name is maximum 10 character.</div>
      </div>
  </div>
   
  <div class="form-group">
      <label for="lastName">Last Name</label>
      <input required ngModel name="lastName" type="text" #lastName="ngModel" class="form-control" id="lastName">
      <div class="alert alert-danger" *ngIf="lastName.touched && !lastName.valid">
          Last Name is required.
      </div>
  </div>
   
  <div class="form-group">
      <label for="comment">Comment</label>
      <textarea required ngModel #comment="ngModel" name="comment" id="comment" cols="30" rows="10" class="form-control"></textarea>
      <div class="alert alert-danger" *ngIf="comment.touched && !firstName.valid">
          Comment is required.
      </div>
  </div>
    
  <button class="btn btn-primary" type="submit" [class.disabled]="!contactForm.valid">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';
   
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  
  submit(form){
    var firstName = form.firstName;
    console.log(firstName);
  
    var lastName = form.lastName;
    console.log(lastName);
  
    var comment = form.comment;
    console.log(comment);
  }
  
}

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...