Ember.js MutableArray slice() 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 slice() method is used to return a new array that is a portion of the receiver.

Syntax:

slice(begin,end)

Parameters:

• begin: Starting index.
• end: Ending index.

Return Value: Portion of receiver between begin and end.

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 details

app/routes/details.js

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

export default class DetailsRoute extends Route {
  details = [
    {
      name: 'Anubhav',
      mobile: '1298119967',
      city: 'Patna',
      country: 'India',
      gender: 'M',
      zipCode: '800020',
    },
    {
      name: 'Sakshi',
      mobile: '1234567890',
      city: 'Mumbai',
      country: 'India',
      gender: 'F',
      zipCode: '400001',
    },
    {
      name: 'Satyam',
      mobile: '2222222222',
      city: 'Delhi',
      country: 'India',
      gender: 'M',
      zipCode: '110012',
    },
    {
      name: 'Shivam',
      mobile: '1122113322',
      city: 'Patna',
      country: 'India',
      gender: 'M',
      zipCode: '530068',
    },
    {
      name: 'Ayushi',
      mobile: '2244668800',
      city: 'Jaipur',
      country: 'India',
      gender: 'F',
      zipCode: '302001',
    },
  ];
  someMoreDetails = [
    {
      name: 'Yeshwant',
      mobile: '1133557799',
      city: 'Chennai',
      country: 'India',
      gender: 'M',
      zipCode: '600001',
    },
    {
      name: 'Siddhant',
      mobile: '9911000000',
      city: 'Mangalore',
      country: 'India',
      gender: 'M',
      zipCode: '574142',
    },
    {
      name: 'Khushi',
      mobile: '8888888888',
      city: 'Pune',
      country: 'India',
      gender: 'F',
      zipCode: '111045',
    },
  ];
  city;
  start;
  end;
  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('start', this.start);
    controller.set('end', this.end);
  }
}

app/controllers/details.js

import Ember from "ember";
import { any, slice, reverseObjects, rejectBy } from "@ember/array";

export default Ember.Controller.extend({
  actions: {
    checkCity(city) {
      let res = this.details.any((person) => person.city == city);
      alert(`Present: ${res ? "YES" : "NO"}`);
    },
    sliceItems(start, end) {
      let tempItems = this.details.slice(start, end);
      let str = "";
      for (let i = 0; i < tempItems.length; i++)
        str += tempItems[i].name + "\n";
      alert(str);
    },
    reverse() {
      this.set("details", this.details.reverseObjects());
    },
    getFemale() {
      let tempItems = this.details.rejectBy("gender", "M");
      let str = "";
      for (let i = 0; i < tempItems.length; i++)
        str += tempItems[i].name + "\n";
      alert(str);
    },
    pushMoreDetails() {
      this.details.pushObjects(this.someMoreDetails);
    },
  },
});

app/template/details.js

{{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"
           {{action 'checkCity' this.city}} />
</div>
<br /><br />
<div>
    <label>Enter Start Index: </label>
    {{input value=this.start}}
</div>
<div>
    <label>Enter End Index: </label>
    {{input value=this.end}}
</div>
<div>
    <input type="button" id="slice-items" value="Slice Items"
           {{action 'sliceItems' this.start this.end}} />
</div>
<br /><br />
<input type="button" id="push-details" value="Add More Details"
       {{action 'pushMoreDetails' }} />
<br /><br />
<input type="button" id="reverse" value="Reverse"
       {{action 'reverse' }} />
<br /><br />
<input type="button" id="get-female" value="Get Female"
       {{action 'getFemale' }} />

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

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

ember generate route party

app/routes/party.js

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

export default class PartyRoute extends Route {
    partyItems = [
        'Digital Camera',
        'Jugs, cups & straws',
        'Balloons',
        'Scissors',
        'Cold Drink',
        'Table Confetti',
        'Party Hats',
        'Wine',
        'Napkins',
        'Party Plates',
        'Speakers',
        'Music System',
        'Cups',
    ];
    itemString;
    itemList;
    start;
    end;
    helper(itemString) {
        this.itemList = itemString.split(',');
        for (let i = 0; i < this.itemList.length; i++)
            this.itemList[i] = this.itemList[i].trim();
        return this.itemList;
    }
    model() {
        return this.partyItems;
    }
    setupController(controller, model) {
        this._super(controller, model);
        controller.set('helper', this.helper);
        controller.set('partyItems', this.partyItems);
        controller.set('itemString', this.itemString);
        controller.set('itemList', this.itemList);
        controller.set('start', this.start);
        controller.set('end', this.end);
    }
}

app/controllers/party.js

import Ember from "ember";
import {
  objectsAt,
  removeObject,
  removeObjects,
  slice,
  reverseObjects,
  setObjects,
  reject,
} from "@ember/array";

export default Ember.Controller.extend({
  actions: {
    getItems(itemString) {
      this.itemList = this.helper(itemString);
      for (let i = 0; i < this.itemList.length; i++)
        this.itemList[i] = parseInt(this.itemList[i]);
      let tempItems = this.partyItems.objectsAt(this.itemList);
      let str = "";
      for (let i = 0; i < tempItems.length; i++)
          str += tempItems[i] + "\n";
      alert(str);
    },
    removeItems(itemString) {
      this.itemList = this.helper(itemString);
      if (this.itemList.length == 1)
        this.partyItems.removeObject(this.itemList[0]);
      else this.partyItems.removeObjects(this.itemList);
      this.set("itemString", "");
    },
    sliceItems(start, end) {
      let tempItems = this.partyItems.slice(start, end);
      let str = "";
      for (let i = 0; i < tempItems.length; i++)
          str += tempItems[i] + "\n";
      alert(str);
    },
    reverseItems() {
      this.set("partyItems", this.partyItems.reverseObjects());
    },
    replaceItems(itemString) {
      this.partyItems.setObjects(this.helper(itemString));
    },
    findMultiwordItems() {
      let reqItem = this.partyItems.reject(
        (item) => item.split(" ").toArray().length == 1
      );
      alert(reqItem);
    },
  },
});

app/template/party.js

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

<br /><br />
<div>
    <label>Enter Items: </label>
    {{input value=this.itemString}}
</div>
<div>
    <input type="button" id="remove-item"
           value="Remove Items"
           {{action 'removeItems' this.itemString}} />
</div>
<br /><br />
<div>
    <label>Enter Start Index: </label>
    {{input value=this.start}}
</div>
<div>
    <label>Enter End Index: </label>
    {{input value=this.end}}
</div>
<div>
    <input type="button" id="slice" value="Slice"
           {{action 'sliceItems' this.start this.end}} />
</div>
<br /><br />
<div>
    <label>Enter Indices: </label>
    {{input value=this.itemString}}
</div>
<div>
    <input type="button" id="get-item" value="Get Items"
           {{action 'getItems' this.itemString}} />
</div>
<br /><br />
<div>
    <label>Enter Items: </label>
    {{input value=this.itemString}}
</div>
<div>
    <input type="button" id="replace-item"
           value="Replace Items"
           {{action 'replaceItems' this.itemString}} />
</div>
<br /><br />
<input type="button" id="reverse-items" value="Reverse"
       {{action 'reverseItems' }} />
<br /><br />
<input type="button" id="find-items" value="Find"
       {{action 'findMultiwordItems' }} />


{{outlet}}

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

Reference: https://api.emberjs.com/ember/4.4/classes/MutableArray/methods