Ember.js MutableArray invoke() Method

Last Updated : 14 Dec, 2022

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 invoke() method is used to call the passed method on every object in the receiver that implements it.

Syntax:

invoke( methodName, args );

Property:

methodName: It is the name of the method which we invoke.
args: It is an optional argument we want to pass to the method.

Return: It returned the return value from calling invoke.

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 invoke1

app/routes/invoke1.js

import Route from '@ember/routing/route'; 
  
class Person { 
    name = null; 
    age = null; 
    country = null; 
    constructor(name, age, country) { 
        this.name = name; 
        this.age = age; 
        this.country = country; 
    } 
  
    greet(prefix = 'Hello') { 
        return `${prefix} ${this.name}`; 
    } 
} 
export default class 
    RichestPeopleRoute extends Route { 
    people = [ 
        new Person('Joe', 26, 'singapore'), 
        new Person('Matt', 29, 'sweden'), 
        new Person('Ram', 21, 'India'), 
        new Person('carl', 23, 'japan'), 
    ]; 
    model() { 
        return this.people; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('people', this.people); 
    } 
}

app/controllers/invoke1.js

import Ember from 'ember'; 
import { mapBy } from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        invoke_greet() { 
  
            let ans = this.people. 
                invoke('greet'); 
  
            alert(ans.join('\n')); 
        }, 
    }, 
});

app/templates/invoke1.hbs

{ { page - title "invoke" } } 
  
<h2>Person in the List</h2> 
  
<table style="border:  
       2px solid black; 
       padding: 30px;"> 
    <tr> 
        <th>Name</th> 
        <th>age</th> 
        <th>country</th> 
    </tr> 
    {{#each @model as |person|}} 
    <tr> 
        <td>{{person.name}}</td> 
        <td>{{person.age}}</td> 
        <td>{{person.country}}</td> 
          
    </tr> 
    {{/each}} 
</table> 
<input type="button"
    id="greet"
    value="Greet to All"
    {{action 'invoke_greet'}} /> 
  
{ { outlet } }

Output: Visit localhost:4200/invoke1 to view the output

invoke2

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

ember generate route invoke2

app/routes/invoke2.js

import Route from '@ember/routing/route'; 
  
class Country { 
    name = null; 
    year = null; 
    constructor(name, year) { 
        this.name = name; 
        this.year = year; 
    } 
  
    Indepedent() { 
        return
        `${this.name} become  
         independent in year ${this.year}`; 
    } 
} 
export default class RichestPeopleRoute  
    extends Route { 
    country = [ 
        new Country('India', 1847), 
        new Country('Brazil', 1822), 
        new Country('Poland', 1918), 
        new Country('Singapore', 1965), 
        new Country('Sudan', 1956), 
    ]; 
    model() { 
        return this.country; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('country', this.country); 
    } 
}

app/controllers/invoke2.js

import Ember from 'ember'; 
import { mapBy } from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        invoke_show() { 
  
            let ans = this.country. 
                invoke('Indepedent'); 
  
            alert(ans.join('\n')); 
        }, 
    }, 
});

app/templates/invoke2.hbs

{ { page - title "invoke" } } 
  
<h2>Person in the List</h2> 
  
<table style="border: 
      2px solid black; 
      padding: 30px;"> 
    <tr> 
        <th>Country</th> 
    </tr> 
    {{#each @model as |country|}} 
    <tr> 
        <td>{{country.name}}</td> 
          
    </tr> 
    {{/each}} 
</table> 
<input type="button"
    id="show"
    value="Print Independent"
    {{action 'invoke_show'}} /> 
  
{ { outlet } }