Ember.js EmberArray reduce() Method

Ember.js is an open-source JavaScript framework used for developing large client-side web applications which are 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 reduce() method is used to combine the enumerator into a single value. It is a useful way of collecting the summary value from the enumerators.

Syntax:

reduce( callback, initialValue, reducerProperty );

Parameters:

• callback: It is the callback that will execute on each function.
• initialValue: It is the initial value for the reducer. 
• reducerProperty: It is for internal use only.

Return Value: A reduced value.

Steps to Install and Rub Ember.js Code:

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 reduce1

app/routes/reduce1.js

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

export default class DetailsRoute
    extends Route {
    details = [
        {
            name: 'Aaksh',
            mobile: '9811129967',
            city: 'Delhi',
            country: 'India',
            gender: 'M',
            zipCode: '800020',
        },
        {
            name: 'Sweta',
            mobile: '9456712890',
            city: 'Mumbai',
            country: 'India',
            gender: 'F',
            zipCode: '400001',
        },
        {
            name: 'Satyam',
            mobile: '2222222222',
            city: 'Raipur',
            country: 'India',
            gender: 'M',
            zipCode: '110012',
        },
        {
            name: 'Shandya',
            mobile: '1122113322',
            city: 'Bangalore',
            country: 'India',
            gender: 'F',
            zipCode: '530068',
        },
        {
            name: 'Ayushi',
            mobile: '2244668800',
            city: 'Thana',
            country: 'India',
            gender: 'F',
            zipCode: '302001',
        },
    ];
    someMoreDetails = [
        {
            name: 'Yogesh',
            mobile: '1133557799',
            city: 'Chennai',
            country: 'India',
            gender: 'F',
            zipCode: '600001',
        },
        {
            name: 'Sunny',
            mobile: '9911000000',
            city: 'Mysore',
            country: 'India',
            gender: 'M',
            zipCode: '574142',
        },
        {
            name: 'Khushi',
            mobile: '8888888888',
            city: 'Pune',
            country: 'India',
            gender: 'F',
            zipCode: '111045',
        },
    ];
    city;
    name;
    code;
    model() {
        return this.details;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('details', this.details);
        controller.set('someMoreDetails',
            this.someMoreDetails);
        controller.set('city', this.city);
        controller.set('code', this.code);
        controller.set('name', this.name);
    }
}

app/controllers/reduce1.js

import Ember from 'ember';
import { addObjects, shiftObject, setEach }
    from '@ember/array';

export default Ember.Controller.extend({
    actions: {
        checkCity(city) {
            let foo = this.details.
                reduce((acc, person) =>
                person.city == this.city ?
                acc + person.name : acc, '');
            foo ? alert(`${foo}  is from ${city} `)
            : alert(`No one from ${city}`);
        },
        checkName(name) {
            let foo = this.details.reduce((acc, person)
             => person.name == this.name ?
             acc + person.city : acc, '');
            foo ? alert(`${name} from ${foo} `)
            : alert(`No one of ${name}`);
        },
        checkCode(code) {
            let foo = this.details.reduce((acc, person)
            => person.zipCode == this.code
            ? acc + person.name : acc, '');
            foo ? alert(`${foo} from ${code} `)
            : alert(`No one of ${code}`);
        },
    },
});

app/templates/reduce1.hbs

{{page-title "Details"}}
<h3>List of People: </h3>
<br /><br />
<table>
    <tr>
        <th>Name</th>
        <th>Gender</th>
        <th>Mobile</th>
        <th>City</th>
        <th>Country</th>
        <th>Zip Code</th>
    </tr>
    {{#each @model as |detail|}}
    <tr>
        <td>{{detail.name}}</td>
        <td>{{detail.gender}}</td>
        <td>{{detail.mobile}}</td>
        <td>{{detail.city}}</td>
        <td>{{detail.country}}</td>
        <td>{{detail.zipCode}}</td>
    </tr>
    {{/each}}
</table>

<br /><br />
<div>
    <label>Enter City: </label>
    {{input value=this.city}}
</div>
<div>
    <input type="button" id="check-city"
        value="Check Someone from City"
        {{action 'checkCity' this.city}} />
</div>
<br /><br />
<div>
    <label>Enter zipCode: </label>
    {{input value=this.code}}
</div>
<div>
    <input type="button" id="check-code"
        value="Check Someone from Zip-Code"
        {{action 'checkCode' this.code}} />
</div><br /><br />
<div>
    <label>Enter Name: </label>
    {{input value=this.name}}
</div>
<div>
    <input type="button" id="check-name"
        value="Check Someone by Name"
        {{action 'checkName' this.name}} />
</div>
{{outlet}}

• Output: Visit localhost:4200/reduce1 to view the output

Ember.js EmberArray reduce method

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

ember generate route reduce2

app/routes/reduce2.js

import Route from '@ember/routing/route';
import { } from '@ember/array';

export default class FruitsRoute
    extends Route {
    item1 = [
        {
            name: 'Apple',
            isFruit: true,
            color: 'red',
        },
        {
            name: 'Grapes',
            isFruit: true,
            color: 'green',
        },
        {
            name: 'Mango',
            isFruit: true,
            color: 'yellow',
        },
        {
            name: 'Watermelon',
            isFruit: true,
            color: 'red',
        },
        {
            name: 'Orange',
            isFruit: true,
            color: 'orange',
        },

    ];
    item2 = [
        {
            name: 'Lady Finger',
            isFruit: false,
            color: 'green',
        },
        {
            name: 'Brinjal',
            isFruit: false,
            color: 'purple',
        },
        {
            name: 'Potato',
            isFruit: false,
            color: 'brown',
        },
        {
            name: 'Onion',
            isFruit: false,
            color: 'violet',
        },
    ];
    model() {
        return this.item1;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('item1', this.item1);
        controller.set('item2', this.item2);
    }
}

app/controllers/reduce2.js

import Ember from 'ember';
import { pushObjects, isAny } from '@ember/array';

export default Ember.Controller.extend({
    actions: {
        Check_item() {
            let ans = this.item1.reduce((acc, item )
            => item.isFruit == true ? acc +
            '\n' + item.name  : acc, '');
            ans ? alert(`Yes it contains Fruit${ans}`)
                : alert(`It doesn't contains any Fruit`)
        },
        Check_item2() {
            let ans = this.item1.reduce((acc, item )
            => item.isFruit == false ? acc
            + '\n' + item.name  : acc, '');
            ans ? alert(`Yes it contains Vegatabe ${ans}`) :
                alert(`It doesn't contains any Vegetable`)
        },
        pushMoreDetails() {
            this.item1.pushObjects(this.item2);
        },
    },
});

app/templates/reduce2.hbs

{{page-title "Fruits"}}
<table style=" border-spacing : 30px">
    <h3>Here is a Bucket: </h3>
    <ul>
        {{#each @model as |eatable|}}
        <li>{{eatable.name}}</li>
        {{/each}}
    </ul>
</table>
<br /><br />
<input type="button" id="fruit-all"
    value="List Contains Any Fruit?"
    {{action 'Check_item' }} />
<br /><br />
<input type="button" id="fruit-notAll"
    value="List Contains Any Vegetables?"
    {{action 'Check_item2' }} />

<br /><br />
<input type="button" id="push-details"
    value="Add More Details"
    {{action 'pushMoreDetails' }} />
{{outlet}}

• Output: Visit localhost:4200/reduce2 to view the output

Ember.js EmberArray reduce method

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