Skip to main content

Angular Template Reference Variable

What Is a Template Reference Variable?
A template reference variable is a way of capturing a reference to a specific element, component, directive, and pipe so that it can be used someplace in the same template HTML.

You should declare a reference variable using the hash symbol (#).

The Angular components and directives only match selectors for classes that are declared in the Angular module.
Template Reference Variable Syntax
You can use a template reference variable by two ways.
1.      Using hash symbol (#)
2.      Using reference symbol (ref-)

The following examples of specifying a template reference variable using Input Text Box
I have declared a reference variable “cellnumber” using the hash symbol (#) and reference symbol (ref-).

<input type="text" ref-cellnumber> //cellnumber will be a template reference variable.

And
<input #cellnumber placeholder="Cell number"> //cellnumber will be a template reference variable.

I have created a reference to the input element that can be used later on in my template and the scope for “cellnumber” variable is the entire HTML template in which the reference is defined.

Here is how I could use that reference to get the value of the input for instance –
//cellnumber refers to the input element
<button (click)="show(cellnumber)">click to see</button>


In the below line of code, the variable “cellnumber” refer to the HTMLElement object instance for the input -

show(cellnumber: HTMLInputElement){
  console.log(cellnumber.value);
}

You can use the ViewChild decorator to reference it inside your component.
import {ViewChild, ElementRef} from '@angular/core';

// Reference cellnumber variable inside Component
@ViewChild('cellnumber') cellInputRef: ElementRef;


And finally, you can use this.nameInputRef anywhere inside your component class.
show(){
  this.contactNumber = this.cellInputRef.nativeElement.value
}

Template Reference Variable with NgForm

Here we will discuss about how to access NgForm directive using template reference variable.
<form (ngSubmit)="onSubmitEmployee(empForm)" #empForm="ngForm">
  <label>F-Name </label><input name="f-name" required [(ngModel)]="employee.fname">
  <label>L-Name </label><input name="l-name" required [(ngModel)]="employee.lname">
  <label>Age    </label><input name="age" required [(ngModel)]="employee.age">
 
  <button type="submit" [disabled]="!empForm.form.valid">Submit</button>
</form>


In the above NgForm example contains an ngSubmit event and form directive.

The ngSubmit – The ngSubmit directive specifies a function to run when the form is submitted. Here on form submit onSubmitEmployee component method will be called.

The NgForm - It is nestable alias of form directive. The main purpose of ngForm is to group the controls, but not a replacement of <form> tag.

As you know, the HTML does not allow nesting of form elements. It is very useful to nest forms.


I hope you enjoyed this post. So please write your thoughts in the below comment box. Thank you so much for reading this post.
By Anil Singh | Rating of this article (*****)

Popular posts from this blog

List of Countries, Nationalities and their Code In Excel File

Download JSON file for this List - Click on JSON file    Countries List, Nationalities and Code Excel ID Country Country Code Nationality Person 1 UNITED KINGDOM GB British a Briton 2 ARGENTINA AR Argentinian an Argentinian 3 AUSTRALIA AU Australian an Australian 4 BAHAMAS BS Bahamian a Bahamian 5 BELGIUM BE Belgian a Belgian 6 BRAZIL BR Brazilian a Brazilian 7 CANADA CA Canadian a Canadian 8 CHINA CN Chinese a Chinese 9 COLOMBIA CO Colombian a Colombian 10 CUBA CU Cuban a Cuban 11 DOMINICAN REPUBLIC DO Dominican a Dominican 12 ECUADOR EC Ecuadorean an Ecuadorean 13 EL SALVA...

nullinjectorerror no provider for httpclient angular 17

In Angular 17 where the standalone true option is set by default, the app.config.ts file is generated in src/app/ and provideHttpClient(). We can be added to the list of providers in app.config.ts Step 1:   To provide HttpClient in a standalone app we could do this in the app.config.ts file, app.config.ts: import { ApplicationConfig } from '@angular/core'; import { provideRouter } from '@angular/router'; import { routes } from './app.routes'; import { provideClientHydration } from '@angular/platform-browser'; //This (provideHttpClient) will help us to resolve the issue  import {provideHttpClient} from '@angular/common/http'; export const appConfig: ApplicationConfig = {   providers: [ provideRouter(routes),  provideClientHydration(), provideHttpClient ()      ] }; The appConfig const is used in the main.ts file, see the code, main.ts : import { bootstrapApplication } from '@angular/platform-browser'; import { appConfig } from ...

Top 15+ Angular 17 Interview Questions Answers | For Experienced Professionals as well

G Google team released the latest version of Angular – Angular 17 on November 6, 2023, creating a significant milestone for the super fast front-end development. What Are the New Features in Angular 17? 1.       Angular 17 is the highly anticipated release for the community, bringing many new exciting features, updates, and improvements. 2.       New Syntax for Control Flow in Templates - new @if, @switch, @for, @case, @empty @end control flow syntax 3.       Deferred Loading - @defer partial template 4.       The Angular signals API 5.       Angular SSR and client hydration 6.       Automatic Migration to Build-in Control Flow 7.       Build Performance with ESBuild 8.       By default, set this newly generated component as a standalone, and now we don't have an app module file. To use (ng...

51 Best React Interview Questions and Answers

1) What Is React? React is a fast, open-source, and front-end JavaScript library and It was developed by Facebook in 2011 for building complex, stateful and interactive UI in web as well as mobile Applications. React follows the component based approach which helps you to building reusable and interactive web and mobile user interface (UI) components. React has one of the largest communities supporting it. The high level component Lifecycle - At the highest level component Lifecycle, React components have lifecycle events that are - 1.       Initialization 2.       State/Property Updates 3.       Destruction Explore to detail understanding   -  React Lifecycle Components Reactjs is very fast technology that can be trusted for complex tasks and can simply be trusted for quality outcomes. 2) When Reactjs released? March 2013 3) What Is the current stable version of ...

Angular 2, 4, 5, 6, 7, 8 and 9 Interview Questions and Answers -Books

» Are you preparing for Angular Interview? Buy this book (Including Angular 8, 7, 6, 5,4, 2) Interview Q/A Interview Q/A Interview Q/A Interview Q/A Interview Q/A Interview Q/A Interview Q/A » A Complete Guide Book of Angular 9 This is a concise, complete overview of the key aspects of Angular 9. It is fully up to date with the latest release of Angular. This article provide all the important aspects required for angular developers looking for brief and useful content... Posted In Angular 9 » A Complete Guide Book of Angular 8 This is a concise, complete overview of the key aspects of Angular 9. It is fully up to date with the latest release of Angular. This article provide all the important aspects required for angular developers looking for brief and useful content... Posted In Angular 8 » A Complete Guide Book of Angular 7 This is a concise, complete overview of the key aspects of Angular 7. It is fully up to date with the latest release of Angular. This ...