Angular 14 ng-template Example to Show & Hide Dynamic Messages Using ngIf and else Statements in TypeScript

Welcome folks today in this blog post we will be looking how to use the ng-template directive in angular 14 to show & hide dynamic messages using the ngIf and else statements in typescript in browser. All the full source code of the application is shown below.

Get Started

In order to get started you need to make a new angular project using the below command as shown below

ng new sampleproject

cd sampleproject

And after that you will see the below directory structure of the angular app as shown below

And now we need to go to app.component.html file and copy paste the below html code where we have the span tag where we have the ngIf and else statements for the boolean variable. And based upon the value of the variable we are showing the two templates. And the template is constructed with the help of ng-template directive and also we have attached the reference to each of the template. And then we have the simple button to toggle the template on button click as shown below.

app.component.html

<div>
  <span *ngIf = "isavailable;then condition1 else condition2">
     Condition is valid.
  </span>
  <ng-template #condition1>Condition is valid from template</ng-template>
  <ng-template #condition2>Condition is invalid from template</ng-template>
</div>
<button (click) = "myClickFunction($event)">Click Me</button>

<div>

Condition is valid.

</span>

<ng-template #condition1>Condition is valid from template</ng-template>

<ng-template #condition2>Condition is invalid from template</ng-template>

</div>

<button (click) = "myClickFunction($event)">Click Me</button>

And now we need to copy paste the below code inside the app.component.ts file as shown below

app.component.ts

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css'],
})
export class AppComponent {
  isavailable = false; // variable is set to true

  myClickFunction(event: any) {
    //just added console.log which will display the event details in browser on click of the button.
    if (this.isavailable) {
      this.isavailable = false;
    } else {
      this.isavailable = true;
    }
  }
}

import { Component, OnInit } from '@angular/core';

@Component({

selector: 'app-root',

templateUrl: './app.component.html',

styleUrls: ['./app.component.css'],

})

export class AppComponent {

isavailable = false; // variable is set to true

myClickFunction(event: any) {

//just added console.log which will display the event details in browser on click of the button.

if (this.isavailable) {

this.isavailable = false;

} else {

this.isavailable = true;

}

As you can see in the above typescript code we have the boolean variable declared and inside the function we are toggling the value of the variable comparing the value inside the if condition. And now if you press the button the template message will change because the variable value will change from true to false and vice versa.