Ember.js EmberArray findBy() Method

Last Updated : 18 Jan, 2023

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 findBy() method is to get the first item with a property matching the passed value.

Syntax:

findBy( key, value );

Property:

key: It is the name of the property that we want to test.
value: it is an optional value that wants to test against the key.

Return Value: It returned the returned item if it finds else return ‘undefined’.

Installation Steps:

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 find-by1

app/routes/find-by1.js

import Route from '@ember/routing/route'; 
import { classify, w } from '@ember/string'; 
import { pushObject, sortBy } from '@ember/array'; 
  
export default class LanguagesRoute extends Route { 
    name = `Hindi Korean Marathi Telugu Portuguese 
        Turkish Bengali Spanish`; 
    num = `343.9 81.7 83.1 82.0 232.4 82.3 233.7 474`; 
  
    languages = []; 
  
    initLanguages() { 
        this.languages = []; 
        this.name = w(this.name); 
        this.num = w(this.num); 
        for (let i = 0; i < this.name.length; i++) { 
            let obj = new Object(); 
            obj['name'] = classify(this.name[i]); 
            obj['num'] = this.num[i]; 
            this.languages.pushObject(obj); 
        } 
    } 
    temp1; 
    model() { 
        this.initLanguages(); 
        return this.languages; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('languages', this.languages); 
        controller.set('temp1', this.temp1); 
    } 
}

app/controlloers/find-by1.js

import Ember from 'ember'; 
import { mapBy } from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        FindNatives(data1) { 
            let ans = this.languages.findBy('name', data1); 
            alert(`${ans.num} Million people speaks ${ans.name}`); 
        }, 
  
    }, 
});

app/templates/find-by1.hbs

{{page-title "Languages"}} 
<h2>Spoken Languages in the World</h2> 
<table style="border: 2px solid black;padding: 30px;"> 
    <tr> 
        <th>Language</th> 
        <th>Native Speakers (in Millions)</th> 
      </tr> 
          {{#each @model as |language|}} 
            <tr> 
                  <td>{{language.name}}</td> 
                  <td>{{language.num}}</td> 
            </tr> 
          {{/each}} 
</table> 
<br /><br /> 
<div> 
    <label> 
        Enter Language Name for search: 
      </label> 
      {{input value=this.temp1}} 
</div> 
<br /> 
<div> 
    <input 
        type="button"
        id="check-language"
        value="Check Language Speaking Population"
        {{action "FindNatives" this.temp1}} 
      /> 
</div> 
{{outlet}}

Output: Visit localhost:4200/find-by1 to view the output

Ember.js EmberArray findBy method

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

ember generate route find-by2

app/routes/find-by2.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: 'Esnoor', 
            gender: 'M', 
            class: 9, 
            grade: 'C', 
        }, 
        { 
            name: 'Isha', 
            gender: 'F', 
            class: 11, 
            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: 'Balit', 
            gender: 'M', 
            class: 12, 
            grade: 'F', 
        }, 
        { 
            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', 
        }, 
    ]; 
    temp1 = ['name', 'gender', 'class', 'grade'] 
    temp2; 
    temp; 
    model() { 
        return this.students; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('students', this.students); 
        controller.set('temp', this.temp); 
        controller.set('temp1', this.temp1); 
        controller.set('temp2', this.temp2); 
    } 
}

app/controlloers/find-by2.js

import Ember from 'ember'; 
  
export default Ember.Controller.extend({ 
    vehicle: null, 
    vehicles: Ember.String.w('Tesla Chrysler Toyota'), 
    actions: { 
        selectattr(temp) { 
            this.set('temp', temp); 
        }, 
        find_Data(data, data1) { 
            data1 = (data === 'class') ? 
                JSON.parse(data1) : data1; 
            let ans = this.students.findBy(data, data1); 
            alert(`${ans.name} from Class ${ans.class}`); 
  
        }, 
    }, 
});

app/templates/find-by2.hbs

{{page-title "Student"}} 
<h3>List of Students: </h3> 
<br /><br /> 
<table> 
    <tr> 
        <th>Name</th> 
        <th>Gender </th> 
        <th>Class </th> 
        <th>Grade </th> 
      </tr> 
      {{#each @model as |detail|}} 
    <tr> 
          <td>{{detail.name}}</td> 
          <td>{{detail.gender}}</td> 
          <td>{{detail.class}}</td> 
          <td>{{detail.grade}}</td> 
    </tr> 
      {{/each}} 
</table> 
<br /> 
<div> 
    <label>Select Attribute: </label> 
      <select onchange={{action "selectattr"
        value="target.value"}}> 
    {{#each this.temp1 as |attribute|}} 
        <option value={{attribute}}>{{attribute}}</option> 
    {{/each}} 
  </select> 
</div> 
<br /> 
<div> 
    <label>Enter value for Attribute: </label> 
     {{input value=this.temp2}} 
</div> 
<div> 
    <input 
        type="button"
        id="check-student"
        value="Get the First Student"
        {{action "find_Data" this.temp this.temp2}} 
      /> 
</div> 
{{outlet}}