Show Validation Message on submit in Angular 4 Reactive Forms

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I am using Angular 4, Reactive forms.I want to show validation error message when the user clicks on Submit/Create Account button. Here is the HTML and typescript code that I am using.

<form [formGroup]="signupForm" (ngSubmit)="onSubmit()">

  <div class="form-group">
    <input type="text" 
           id="firstname" 
           name="firstname" 
           formControlName="firstname" 
           placeholder="First Name">
    <span *ngIf="!signupForm.get('firstname').valid && signupForm.get('firstname').touched" 
           class="help-block"> Please Enter First Name (Minimum 2 Characters)</span>
  </div>

  <div class="form-group">
    <input type="text" 
           id="lastname" 
           name="lastname" 
           formControlName="lastname" 
           placeholder="Last Name">
    <span *ngIf="!signupForm.get('lastname').valid && signupForm.get('lastname').touched" 
           class="help-block"> Please Enter Last Name (Minimum 2 Characters)</span>
  </div>

  <div class="form-group">
    <button type="submit" 
            class="btn btn-success btn-lg btn-qte">Create Account</button>
  </div>

</form>

TYPE SCRIPT CODE


export class UserRegistrationComponent implements OnInit {
    signupForm: FormGroup;

    ngOnInit() {
        this.signupForm = new FormGroup({
            'firstname': new FormControl(null, [Validators.required, Validators.minLength(2)]),
            'lastname': new FormControl(null, [Validators.required, Validators.minLength(2),]),
            'businessname': new FormControl(null),
            'phonenumber': new FormControl(null, [Validators.required]),
            'email': new FormControl(null, [Validators.required, Validators.email]),
            'password': new FormControl(null, [Validators.required]),
            'confirmpassword': new FormControl(null, Validators.required)

        });
    }

    onSubmit() {
        console.log(this.signupForm)
    }

}

Something like

onSubmit() {
    console.log(this.signupForm)
    this.signupForm.controls['firstname'].markAsTouched()
}

Angular Reactive Forms: trigger validation on submit, Forms are a fundamental part of every angular application. One of the greatest features of forms is, that you can validate the input of the user before it is… The submit-button will disabled while our contactForm is not valid. If that was a little bit to Adjusting the template to show error messages. Now we  When working with forms we have 2 options: the first one is to disable the submit button if the form is invalid (meaning there is at least one invalid field) and the second option is to validate the form before the HTTP POST action is executed by the code and display a message to the user to fix any pending validation errors.


To get the properties like touched, dirty, valid of form control through formGroup use :

signupForm.controls.firstname.touched. same way you can get the other properties like valid and invalid.

if you have created individual object of FormControl then, you can access that object properties as firstname.touched without using formGroup.

for more information about the validation in Model Driven Forms refer Model Driven Form Validations here.

Show form errors on submit in Angular, The example is a simple registration form that validates on submit. This is a quick example of how to setup form validation in Angular 6 using Reactive Forms. Styling of the example is all done with Bootstrap 4 CSS. Validation messages are displayed only after the user attempts to submit the form for  In component I have created form using form builder: For contact Number feild I have added validation mobRegex and I want to show msg when pattern does not match.


you can do this using from markAllAsTouched() method. it will mark all the form controls as touched and by doing so will trigger validation errors where needed

onSubmit() {
    this.signupForm.markAllAsTouched();
}

Validating Reactive Forms in Angular, The example is a simple registration form that validates on submit, and includes This is a quick example of how to setup form validation in Angular 7 using Reactive Forms. Styling of the example is all done with Bootstrap 4 CSS. Validation messages are displayed only after the user attempts to submit  In this post, I will demonstrate how to make the validation and show you how easy is to make forms validation in angular. We are going to make one single component that handles all the validation.


Angular 6, With validator directives, working with Angular 4 forms is easy. This way, by leveraging the onSubmit event, we have access to the NgForm component show-errors.component.ts import { Component, Input } from '@angular/core'; import The reactive forms are a new approach towards the support of Angular 4 forms,  There are two types of forms in Angular: Template Driven Forms and Reactive Forms. Today, we will focus on Reactive forms. Reactive Form Validation. Reactive forms are also known as model-driven forms. This means that the HTML content changes depending on the code in the component. In reactive forms, we add validator functions directly to the


Angular 7, If you're new to forms, start by reviewing the Forms and Reactive Forms You may not want your application to display errors before the user has a chance to edit the form. minLength(4) —and one custom validator, forbiddenNameValidator . by changing the updateOn property from change (​default) to submit or blur . In a reactive form, the source of truth is the component class. Instead of adding validators through attributes in the template, you add validator functions directly to the form control model in the component class. Angular then calls these functions whenever the value of the control changes.


Angular 4 Forms: Nesting and Input Validation, Open a command window and run the command shown below: ng new angular-​forms-validation --routing=false --style=scss confirmPasswordControl.errors. We will validate the following four conditions using the regular expression: registerForm.valid) { alert('Form Submitted succesfully!!!\n Check  The form binds the form submit event to the onSubmit () handler in the app component using the Angular event binding (ngSubmit)="onSubmit ()". Validation messages are displayed only after the user attempts to submit the form for the first time, this is controlled with the submitted property of the app component.