Ember.js EmberArray map() 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 map() method is used to map all the items in the enumeration to another value.

Syntax:

map( callback, target );

Parameters:

• callback: It is the callback that is executed on each item.
• target: It is the target item on which the callback function will perform.

Return Value: A mapped array.

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 serve

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

ember generate route map1

app/routes/map1.js

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

export default class WebsitesRoute
    extends Route {
    food = [
        {
            food: 'apple',
            quant: 1.5,
            Bucket: 1,
        },
        {
            food: 'Potato',
            quant: 3,
            Bucket: 2,
        },
        {
            food: 'Banana',
            quant: 2,
            Bucket: 1,
        },
        {
            food: 'grapes',
            quant: 3,
            Bucket: 2,
        },
        {
            food: 'Orange',
            quant: 2,
            Bucket: 1,
        },
        {
            food: 'Pine-apple',
            quant: 1,
            Bucket: 2,
        },
        {
            food: 'bean',
            quant: 3,
            Bucket: 2,
        },
    ];
    temp;
    model() {
        return this.food;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('food', this.food);
        controller.set('temp', this.temp);
        controller.set('temp2', this.temp2);
    }
}

app/controllers/map1.js

import Ember from 'ember';
import { map } from '@ember/array';

export default Ember.Controller.extend({
    actions: {
        increase_quant(data) {
            this.food.map((item) =>
                Ember.set(item, 'quant',
                    (item.quant) + +data));

        },
        shift_bucket() {
            this.food.map((item) =>
                Ember.set(item, 'Bucket',
                 item.Bucket == 1
                    ? 2 : 1));

        },
    },
});

app/templates/map1.hbs

{{page-title "invoke"}}

<h2>List of Item with Quantity </h2>

<table>
    <tr>
        <th>Name</th>
        <th>Quantity</th>
        <th>Bucket</th>
    </tr>
    {{#each @model as |Eatable|}}
        <tr>
            <td>{{Eatable.food}}</td>
            <td>{{Eatable.quant}}</td>
            <td>{{Eatable.Bucket}}</td>

        </tr>
    {{/each}}
</table>
<br />

<div>
    <label>Enter quantity: </label>
    {{input value=this.qut}}
</div>
<input
    type="button"
    id="greet"
    value="Increase_quant"
    {{action "increase_quant" this.qut}}
/>

<br /><br />
<input
    type="button"
    id="greet"
    value="Shift Bucket"
    {{action "shift_bucket"}}
/>
{{outlet}}

Output: Visit localhost:4200/map1 to view the output

Ember.js EmberArray map method

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

ember generate route mapBy2

app/routes/map2.js

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

export default class StudentsRoute extends Route {
    students = [
        {
            name: 'Aakash',
            gender: 'M',
            class: 10,
            grade: 'A',
        },
        {
            name: 'Soniya',
            gender: 'F',
            class: 8,
            grade: 'C',
        },
        {
            name: 'Sita',
            gender: 'F',
            class: 10,
            grade: 'A',
        },
        {
            name: 'Ram',
            gender: 'M',
            class: 10,
            grade: 'A',
        },
        {
            name: 'Esnoor',
            gender: 'M',
            class: 9,
            grade: 'C',
        },
        {
            name: 'Isha',
            gender: 'F',
            class: 19,
            grade: 'B',
        },
        {
            name: 'Doman',
            gender: 'M',
            class: 12,
            grade: 'B',
        },
        {
            name: 'Lolu',
            gender: 'M',
            class: 10,
            grade: 'A',
        },
        {
            name: 'Lucky',
            gender: 'M',
            class: 11,
            grade: 'F',
        },
        {
            name: 'Neha',
            gender: 'F',
            class: 10,
            grade: 'B',
        },
        {
            name: 'Balit',
            gender: 'M',
            class: 12,
            grade: 'F',
        },
        {
            name: 'Hillier Buchanan',
            gender: 'M',
            class: 12,
            grade: 'A',
        },
        {
            name: 'Aman',
            gender: 'M',
            class: 11,
            grade: 'B',
        },
        {
            name: 'Anuj',
            gender: 'M',
            class: 12,
            grade: 'F',
        },
        {
            name: 'Satyam',
            gender: 'M',
            class: 12,
            grade: 'F',
        },
        {
            name: 'Aayush',
            gender: 'M',
            class: 12,
            grade: 'C',
        },
    ];
    temp2;
    model() {
        return this.students;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('students', this.students);
        controller.set('temp2', this.temp2);
    }
}

app/controllers/map2.js

import Ember from "ember";
import { filter } from "@ember/array";

export default Ember.Controller.extend({
    actions: {
        allPass() {
            let ans = '';
            let temp = this.students.map((item) =>
                item.grade == 'F' ? ans += item.name
                    + '\n' : '');
            alert(ans);
        },
        allFemale() {
            let ans = '';
            let temp = this.students.map((item)
                => item.gender == 'F' ?
                    ans += item.name + '\n' : '');
            alert(ans);
        },
        allClass(data) {
            let ans = '';
            let temp = this.students.filter((item) =>
                item.class == JSON.parse(data) ?
                    ans += item.name + '\n' : '');
            alert(ans);
        },
    }
});

app/templates/map2.hbs

{{page-title "Students"}}
<h3>List of Students: </h3>
<br /><br />
<table>
    <tr>
        <th>Name</th>
        <th>Class</th>
        <th>Gender</th>
        <th>Grade</th>
    </tr>
    {{#each @model as |student|}}
        <tr>
            <td>{{student.name}}</td>
            <td>{{student.class}}</td>
            <td>{{student.gender}}</td>
            <td>{{student.grade}}</td>
        </tr>
    {{/each}}
</table>
<br />
<input
    type="button"
    id="all-pass"
    value="Failed Student"
    {{action "allPass"}}
/>
<br /><br />
<input
    type="button"
    id="all-female"
    value="All are Female"
    {{action "allFemale"}}
/>
<br /><br />
<div>
    <label>Enter Class: </label>
    {{input value=this.temp2}}
</div>
<br />
<input
    type="button"
    id="all-class"
    value="All are in Same class"
    {{action "allClass" this.temp2}}
/>
{{outlet}}

Output: Visit localhost:4200/map2 to view the output

Ember.js EmberArray map method

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