Angular Reactive Form Set Custom Error Messages Working Example

Hello to all, welcome to therichpost.com. In this post, I will tell you, Angular Reactive Form Set Custom Error Messages Working Example.

Guys with this we will cover below things:

1. Angular 14 Reactive Form Implelemtnation.
2. Reactive forms validation email with valid format.
3. Reactive form checkbox validation.
4. Angular14 Reactive Form Responsiveness with Bootstrap 5.

Angular14 came and if you are new then you must check below link:

1. Angular 14 Tutorials

Here is the code snippet and please use carefully:

1. Very first guys, here are common basics steps to add angular 14 application on your machine and also we must have latest nodejs latest version installed for angular 14:

$ npm install -g @angular/cli

$ ng new angularform // Set Angular 14 Application on your pc

cd angularform // Go inside project folder

2. Now run below commands to set bootstrap 5 modules into our angular 14 application for responsiveness (optional):

npm install bootstrap

npm i @popperjs/core

3. Now friends we just need to add below code into angularform/angular.json file (optional):

"styles": [
              ...
              "node_modules/bootstrap/dist/css/bootstrap.min.css"
          ],
"scripts": [
              ...
               "node_modules/bootstrap/dist/js/bootstrap.min.js"
           ]

4. Now guys we will add below code into our angularform/src/app/app.module.ts file:

...
import { ReactiveFormsModule } from '@angular/forms';

@NgModule({
...
  imports: [
   ...
    ReactiveFormsModule,
   
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

5. Now guys we will add below code into our angularform/src/app/app.component.ts file:

import { Component } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'angular14demos';

  //Form Validables 
registerForm:any = FormGroup;
submitted = false;

//custom error message bolean variable
customEmailErrorMessage = false;

constructor( private formBuilder: FormBuilder){}
//Add user form actions
get f() { return this.registerForm.controls; }
onSubmit() {
  
  this.submitted = true;
  // stop here if form is invalid
  if (this.registerForm.invalid) {
      return;
  }
  //True if all the fields are filled
  if(this.submitted)
  {

    //demo how we can set custom error messages very easily
    this.registerForm.controls['email'].setErrors({ incorrect: true}); 
    this.customEmailErrorMessage = true;
  }
 
}
  ngOnInit() {
    //Add User form validations
    this.registerForm = this.formBuilder.group({
    email: ['', [Validators.required, Validators.email]],
    password: ['', [Validators.required]],
    address: ['', [Validators.required]],
    city: ['', [Validators.required]],
    state: ['', [Validators.required]],
    zip: ['', [Validators.required]],
    checkmeout: ['', [Validators.requiredTrue]]
    });
  }
}

6. Finally we will add below code into our angularform/src/app/app.component.html file:

<div class="container p-5">
  
  <form class="row g-3" [formGroup]="registerForm" (ngSubmit)="onSubmit()">
    <div class="col-md-6">
      <label for="inputEmail4" class="form-label">Email</label>
      <input type="email" formControlName="email" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.email.errors }"  id="inputEmail4">
      <div *ngIf="submitted && f.email.errors" class="invalid-feedback">
        <div *ngIf="f.email.errors.required">Email is required</div>
        <div *ngIf="f.email.errors.email">Email must be a valid email address</div>

        <!--custom error message-->
        <div *ngIf="customEmailErrorMessage">Email already exists</div>

     </div>
    </div>
    <div class="col-md-6">
      <label for="inputPassword4" class="form-label">Password</label>
      <input type="password" formControlName="password" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.password.errors }" id="inputPassword4">
      <div *ngIf="submitted && f.password.errors" class="invalid-feedback">
        <div *ngIf="f.password.errors.required">Password is required</div>
     </div>
    </div>
    <div class="col-12">
      <label for="inputAddress" class="form-label">Address</label>
      <input type="text" formControlName="address" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.address.errors }" id="inputAddress" placeholder="1234 Main St">
      <div *ngIf="submitted && f.address.errors" class="invalid-feedback">
        <div *ngIf="f.address.errors.required">Password is required</div>
     </div>
    </div>
    <div class="col-md-6">
      <label for="inputCity" class="form-label">City</label>
      <input placeholder="Ludhiana" type="text" formControlName="city" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.city.errors }" id="inputCity">
      <div *ngIf="submitted && f.city.errors" class="invalid-feedback">
        <div *ngIf="f.city.errors.required">City is required</div>
     </div>
    </div>
    <div class="col-md-4">
      <label for="inputState" class="form-label">State</label>
      <select id="inputState" class="form-select" formControlName="state" [ngClass]="{ 'is-invalid': submitted && f.state.errors }">
        <option value="">Choose...</option>
        <option value="punjab">Punjab</option>
      </select>
      <div *ngIf="submitted && f.state.errors" class="invalid-feedback">
        <div *ngIf="f.state.errors.required">State is required</div>
     </div>
    </div>
    <div class="col-md-2">
      <label for="inputZip" class="form-label">Zip</label>
      <input type="text" formControlName="zip" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.zip.errors }" id="inputZip">
      <div *ngIf="submitted && f.zip.errors" class="invalid-feedback">
        <div *ngIf="f.zip.errors.required">State is required</div>
     </div>
    </div>
    <div class="col-12">
      <div class="form-check">
        <input value="" class="form-check-input" formControlName="checkmeout" [ngClass]="{ 'is-invalid': submitted && f.checkmeout.errors }" id="inputZip" type="checkbox" id="gridCheck">
        <label class="form-check-label" for="gridCheck">
          Check me out
        </label>
        <div *ngIf="submitted && f.checkmeout.errors" class="invalid-feedback">
          <div *ngIf="f.checkmeout.errors.required">This is required</div>
       </div>
      </div>
    </div>
    <div class="col-12">
      <button type="submit" class="btn btn-primary">Sign in</button>
    </div>
  </form>
</div>

Now we are done friends and please run ng serve command to check the output in browser(locahost:4200) and if you have any kind of query then please do comment below.

Note: Friends, I just tell the basic setup and things, you can change the code according to your requirements. For better understanding please watch video above.

Guys I will appreciate that if you will tell your views for this post. Nothing matters if your views will be good or bad.

Jassa

Thanks