Ember.js Ember.Templates.helpers on() Method

Ember.js is an open-source JavaScript framework used for developing large client-side web applications which is based on Model-View-Controller (MVC) architecture. Ember.js is one of the most widely used front-end application frameworks. It is made to speed up development and increase productivity. Currently, it is utilized by a large number of websites, including Square, Discourse, Groupon, Linked In, Live Nation, Twitch, and Chipotle.

The on() method is used to add the event listeners. 

Syntax:

{{ on event callback }}

Parameters: 

• event: It is an event to which a callback will invoke.
• callback: It is a callback that invokes an event.

Steps to Install and Run Ember.js:

Step 1: To run the following examples you will need to have an ember project with you. To create one, you will need to install ember-cli first. Write the below code in the terminal:

npm install ember-cli

Step 2: Now you can create the project by typing in the following piece of code:

ember new <project-name> --lang en

To start the server, type:

ember serve

Example 1: Type the following code to generate the route for this example:

ember generate route on1

app/components/arr.js

Javascript

import Component from '@glimmer/component';
import { tracked } from '@glimmer/tracking';
import { action, addObjects } from '@ember/object';
export default class CompactComponent extends Component {
    items = [
        'Oxygen',
        'Source Code',
        'Infine',
        'Tenet',
        'SpiderHead',
        'The Thing',
        'A Quiet Place',
        'The Invisible Man',
        'Looper',
        'Ad Astra',
    ];

    @action
    remove(data) {
        this.items.removeObject(data);
    }
}

app/components/arr.hbs

HTML

{{#if @show}}
<ul>
    <h3>{{yield}} : </h3>
    {{#each this.items as |party|}}
    <li>{{unbound party}}</li>
    {{/each}}
</ul>
<br />
{{textarea value=this.value}}
<br />
<input type="button" id="check-atIndex"
    value="Remove"
    {{on 'click' (fn this.remove this.value)}} />
<br /><br />
{{else}}

This component Don't Have block!!<br />
{{/if}}

app/templates/on1.hbs

HTML

<Arr @show={{true}}>
    List of items
</Arr>
{{outlet}}

Output:

Ember.js Ember.Templates.helpers on() Method

Example 2: Type the following code to generate the route for this example:

ember generate route on2

app/components/arr2.js

Javascript

import Component from '@glimmer/component';
import { tracked } from '@glimmer/tracking';
import { action } from '@ember/object';
import { mapBy } from '@ember/object';

export default class extends Component {
    @tracked
    value = 'name';

    @tracked
    value2 = 'c++';
    student = [
        {
            name: 'Sam Snehil',
            age: 21,
            skill: 'Python',
        },
        {
            name: 'Satyam Sahu',
            age: 23,
            skill: 'JavaScript',
        },
        {
            name: 'Sohan Argrwal',
            age: 25,
            skill: 'Html',
        },
        {
            name: 'Sreya Sarma',
            age: 19,
            skill: 'PHP',
        },
        {
            name: 'Satyam Sahu',
            skill: 'Angular',
        },
    ];

    @action
    print(data1, data2) {
        this.student.setEach(data1, data2);
    }
}

app/components/arr2.hbs

HTML

{{yield}}
<table>
    <tr>
        <th>Name</th>
        <th>Age</th>
        <th>skill</th>
    </tr>
    {{#each this.student as |detail|}}

    {{#if detail.age}}
    <tr>
        <td>{{unbound (get detail 'name')}}</td>
        <td>{{get detail 'age'}}</td>
        <td>{{get detail 'skill'}}</td>
    </tr>
    {{else}}
    <tr>
        <td>{{unbound (get detail 'name')}}</td>
        <td>{{18}}</td>
        <td>{{get detail 'skill'}}</td>
    </tr>
    {{/if}}
    {{/each}}
</table>
<br />
{{textarea value=this.value}}

{{textarea value=this.value2}}
<br />
<input type="button" id="set-code"
    value="Update Student details"
    {{on 'click' (fn this.print this.value
    this.value2)}} />

app/templates/array2.hbs

HTML

<Arr2>
    <h1>List of Student :</h1>
</Arr2>
{{outlet}}

Output:

Ember.js Ember.Templates.helpers on() Method

Reference: https://api.emberjs.com/ember/4.6/classes/Ember.Templates.helpers/methods/on?anchor=on