Ember.js ArrayProxy unshiftObject() 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 unshiftObject() method is used to unshift an object to the start of the array.

Syntax:

unshiftObject( obj );

Parameters:

• obj: It is the object name of the property whose value we want to set.

Return Value: A Object with the object passed.

Steps to Install and Run Ember.js:

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

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 server

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

ember generate route unshifObject1

• app/routes/unshiftObject1.js

Javascript

import Route from '@ember/routing/route';

export default class ListRoute extends Route {
    list = [
        "Digital Camera",
        "Speakers",
        "Balloons",
        "Scissors",
        "Cups",
        "Table Confetti",
        "Scissors",
        "Wine",
        "Napkins",
        "Party Plates",
        "Speakers",
        "Music System",
        "Cups",];
    item;
    idx;
    model() {
        return this.list;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('list', this.list);
        controller.set('item', this.item);
        controller.set('idx', this.idx);
    }
}

• app/controllers/unshiftObject1.js

Javascript

import Ember from 'ember';
import { lastIndexOf, includes, addObject, clear }
    from '@ember/array';

export default Ember.Controller.extend({
    actions: {
        reverse() {
            this.list.setObjects(this.list.reverseObjects());
        },
        remove_d() {
            let k = this.list.uniq();
            this.list.setObjects(k);
        },
        add_first(item) {
            this.list.unshiftObject(item);
        },
    },
});

• app/templates/unshiftObject1.hbs

Javascript

{{page-title "unshiftObject"}}
<h3>Here is a list of Items: </h3>
<ul>
    {{#each @model as |i|}}
        <li>{{i}}</li>
    {{/each}}
</ul>

<br />
<div>
    <label>Enter Item: </label>
    {{input value=this.item}}
</div>
<div>
    <input
        type="button"
        id="insert-item"
        value="Insert at Begining"
        {{action "add_first" this.item}}
    />
</div>
<br />
<input
    type="button"
    id="remove-duplicates"
    value="Remove duplicates"
    {{action "remove_d"}}
/>

<br /><br />
<input
    type="button"
    id="reverse_list"
    value="Reverse List"
    {{action "reverse"}}
/>
{{outlet}}

Output: Visit localhost:4200/unshiftObject1 to view the output

Ember.js ArrayProxy unshiftObject method

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

ember generate route unshiftObject2

• app/routes/unshiftObject2.js

Javascript

import Route from '@ember/routing/route';

export default class PartyRoute extends Route {
    partyItems = [
        'Oxygen',
        'Tenet',
        'Source Code',
        'Infine',
        'Loopert',
        'Tenet',
        'SpiderHead',
        'The Thing',
        'A Quiet Place',
        'The Invisible Man',
        'Looper',
        'The Thing',
        'Ad Astra'
    ];
    temp = [
        'Shutter Island',
        'Matrix',
        'Avatar',
        'Fantastic Beast',
        'Avengers',
        'Fantastic four',
        'HulK',
        'Superman',
        'Spiderman',
        'The Batman'
    ];
    item;
    idx;
    model() {
        return this.partyItems;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('partyItems', this.partyItems);
        controller.set('item', this.item);
        controller.set('idx', this.idx);
        controller.set('temp', this.temp);
    }
}

• app/controllers/unshiftObject2.js

Javascript

import Ember from 'ember';
import { pushObject, pushObjects, lastIndexOf, includes }
    from '@ember/array';

export default Ember.Controller.extend({
    actions: {
        invert() {
            this.partyItems.reverseObjects( );

        },
        insert_first(data) {
            this.partyItems.unshiftObject(data);
        },
        remove_d() {
            let res = this.partyItems.uniq();
            this.partyItems.setObjects(res)
        },
    },
});

• app/templates/unshiftObject2.hbs

Javascript

{{page-title "unshiftObject"}}
<h3>Here is a list of items: </h3>
<ul>
    {{#each @model as |party|}}
        <li>{{party}}</li>
    {{/each}}
</ul>
<br /><br />
<div>
    <label>Enter Item: </label>
    {{input value=this.item}}
</div>
<div>
    <input
        type="button"
        id="insert-begining"
        value="Insert at Begining"
        {{action "insert_first" this.item }}
    />
</div>
<br />

<input type="button"
     id="reverse_list"
     value="Reverse List"
    {{action "invert"}} />
<br /><br/>
<input type="button"
     id="remove-duplicates"
     value="Remove duplicates"
    {{action "remove_d"}} />
{{outlet}}

Output: Visit localhost:4200/unshiftObject2 to view the output

Ember.js ArrayProxy unshiftObject method

Reference: https://api.emberjs.com/ember/2.14/classes/Ember.Array/methods/unshiftObject?anchor=unshiftObject