Ember.js EmberArray rejectBy() 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 rejectBy() method returns an array containing the objects for which the given key’s value is false.

Syntax:

rejectBy(key,value)

Parameters:

• key: Property to test.
• value: Optional value to check against.

Return Value: New array.

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 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.hbs

{{page-title "Websites"}}
<h3>Websites</h3>
<br /><br />
<table>
    <tr>
        <th>Name</th>
        <th>Website Link</th>
      </tr>
      {{#each @model as |website|}}
    <tr>
      <td>{{website.name}}</td>
      <td>{{website.link}}</td>
    </tr>
      {{/each}}
</table>
<br /><br />
<input type="button" id="add-website"
    value="More Websites" {{action "add"}} />
<br /><br />
<input type="button" id="set-website"
    value="Click Here" {{action "set"}} />
{{outlet}}

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 richest-people

app/routes/richest-people.js

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

export default class RichestPeopleRoute extends Route {
    richestPeople = [
        { name: "mukesh ambani", netWorth: 90.7,
          isFamily: false },
        { name: "jeff Bezos", netWorth: 148.1,
          isFamily: false },
        { name: "Warren Buffet", netWorth: 99.3,
          isFamily: false },
        { name: "Bill gates", netWorth: 104.7,
          isFamily: false },
        { name: "elon Musk", netWorth: 253.4,
          isFamily: false },
        { name: "gautam adani and family",
          netWorth: 115.8, isFamily: true },
        { name: "Larry Page", netWorth: 93.4,
          isFamily: false },
        { name: "larryEllison", netWorth: 103.3,
          isFamily: false },
        { name: "sergeyBrin", netWorth: 89.9,
          isFamily: false },
        { name: "bernard Arnault and family",
          netWorth: 157.1, isFamily: true },
    ];
    firstPerson;
    lastPerson;
    idx = 5;
    randomPerson;
    num;
    model() {
        this.richestPeople =
        this.richestPeople.sortBy("netWorth");
        this.randomPerson =
        this.richestPeople[this.idx - 1];
        return this.richestPeople;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set("idx", this.idx);
        controller.set("firstPerson", this.richestPeople.firstObject);
        controller.set("lastPerson", this.richestPeople.lastObject);
        controller.set("randomPerson", this.randomPerson);
        controller.set("richestPeople", this.richestPeople);
        controller.set("num", this.richestPeople.length);
    }
}

app/controllers/richest-people.js

import Ember from "ember";

export default Ember.Controller.extend({
    actions: {
        check(num) {
            num = parseFloat(num);
            let res = this.richestPeople.any((person) =>
            person.netWorth >= num);
            alert(`${res ? "YES" : "NO"}`);
        },
        getFamilyBusiness() {
            let tempItems =
            this.richestPeople.rejectBy("isFamily", false);
            let str = "";
            for (let i = 0; i < tempItems.length; i++)
                str += tempItems[i].name + "\n";
            alert(str);
        },
    },
});

app/template/richest-people.hbs

{ { page - title "Richest People" } }
<h2>Richest People in the World</h2>
<table style="border: 2px solid black;padding: 30px;">
    <tr>
        <th>Name</th>
        <th>Net Worth (in billions $)</th>
      </tr>
      {{#each @model as |person|}}
    <tr>
        <td>{{person.name}}</td>
          <td>{{person.netWorth}}</td>
    </tr>
      {{/each}}
</table>
<br /><br />
<div>
    <label>Enter Value: </label>
      {{input value=this.num}}
</div>
<div>
    <input
        type="button"
        id="check"
        value="Contains Person With More Net Worth"
        {{action "check" this.num}}
      />
</div>
<br /><br />
<input
    type="button"
      id="get-family"
      value="Get Family Business"
      {{action "getFamilyBusiness"}}
/>
{{outlet}}

Output: Visit localhost:4200/richest-people to view the output:

Reference: https://api.emberjs.com/ember/4.6/classes/EmberArray/methods/