Ember.js Ember.NativeArray mapBy() 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 mapBy() method is used to get the value of the named property on all items in the enumeration. It is similar to the map method.
Syntax:
mapBy( key );
Parameters:
- key: It is the name of property whose value we want.
Return Value: A mapped array.
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 mapBy1
app/routes/mapBy1.js
Javascript
import Route from "@ember/routing/route" ; class employee { name = null ; mobile = null ; city = null ; country = null ; gender = null ; zipCode = null ; constructor(name, mobile, city, country, gender, zipCode) { this .name = name; this .mobile = mobile; this .city = city; this .country = country; this .gender = gender; this .zipCode = zipCode; } get_add() { return `${ this .name} is Employee from ${ this .city}`; } } export default class DetailsRoute extends Route { details = [ new employee( "Anubhav" , "1298119967" , "Patna" , "India" , "M" , "800020" ,), new employee( "Yogesh" , "1234567890" , "Raipur" , "India" , "M" , "402001" ), new employee( "Satyam" , "2222222222" , "Delhi" , "India" , "M" , "110012" ), new employee( "Shivam" , "1122113322" , "Patna" , "India" , "M" , "530068" ), new employee( "Ayushi" , "2244668800" , "Jaipur" , "India" , "F" , "302001" ) ]; city; start; end; model() { return this .details; } setupController(controller, model) { super .setupController(controller, model); controller.set( "details" , this .details); controller.set( "city" , this .city); controller.set( "start" , this .start); controller.set( "end" , this .end); } } |
app/controllers/mapBy1.js
Javascript
import Ember from "ember" ; import { isAny } from "@ember/array" ; export default Ember.Controller.extend({ actions: { getNames() { let ans = this .details.mapBy( 'name' ); alert(ans.join( '\n' )); }, showAdd() { let res = this .details.invoke( 'get_add' ); alert(res.join( '\n' )); }, checkFemale() { let res = this .details.isAny( 'gender' , 'F' ); alert(res ? `Female employee present in List` : `No Female present`); }, }, }); |
app/templates/mapBy1.hbs
Javascript
import Ember from "ember" ; import { isAny } from "@ember/array" ; export default Ember.Controller.extend({ actions: { getNames() { let ans = this .details.mapBy( 'name' ); alert(ans.join( '\n' )); }, showAdd() { let res = this .details.invoke( 'get_add' ); alert(res.join( '\n' )); }, checkFemale() { let res = this .details.isAny( 'gender' , 'F' ); alert(res ? `Female employee present in List` : `No Female present`); }, }, }); |
Output: Visit localhost:4200/mapBy1 to view the output
Example 2: Type the following code to generate the route for this example:
ember generate route mapBy2
app/routes/mapBy2.js
Javascript
import Route from '@ember/routing/route' ; import { } from '@ember/array' ; class fruit { name = null ; isFruit = null ; color = null ; constructor(name, isFruit, color) { this .name = name; this .isFruit = isFruit; this .color = color; } show_item() { return `${ this .name} is ${ this .isFruit ? '' : 'not' } fruit`; } } export default class FruitsRoute extends Route { fruits = [ new fruit( 'Lady Finger' , false , 'green' ), new fruit( 'Brinjal' , false , 'purple' ), new fruit( 'Apple' , true , 'red' ), new fruit( 'Grapes' , true , 'green' ), new fruit( 'Mango' , true , 'yellow' ), new fruit( 'Watermelon' , true , 'red' ), new fruit( 'Orange' , true , 'orange' ) ]; model() { return this .fruits; } setupController(controller, model) { super .setupController(controller, model); controller.set( 'fruits' , this .fruits); } } |
app/controllers/mapBy2.js
Javascript
import Ember from "ember" ; import { isAny, isEvery } from "@ember/array" ; export default Ember.Controller.extend({ actions: { showFruit() { let ans = this .fruits.invoke( "show_item" ) alert(ans.join( '\n' )); }, alertFruit() { let ans = this .fruits.mapBy( "name" ); alert(ans.join( '\n' )); }, checkFruits() { let ans = this .fruits.isAny( 'isFruit' , true ); alert(ans ? "Fruits present in list" : "Fruits not present in list" ) }, checkvegy() { let ans = this .fruits.isAny( 'isFruit' , false ); alert(!ans ? "Vegetables present in list" : "Vegetables not present in list" ) }, }, }); |
app/templates/mapBy2.hbs
Javascript
{{page-title "mapBy" }} <h3>Here is a list of eatables: </h3> <ul> {{ #each @model as |eatable|}} <li> {{eatable.name}} </li> {{/each}} </ul> <br /> <input type= "button" id= "fruit-show" value= "Check Fruits" {{action "showFruit" }} /> <br /><br /> <input type= "button" id= "fruit-all" value= "Alert all Item names" {{action "alertFruit" }} /> <br /><br /> <input type= "button" id= "check-Fruits" value= "Check any Fruit" {{action "checkFruits" }} /> <br /><br /> <input type= "button" id= "check-NonFruits" value= "Check any Vegetables" {{action "checkvegy" }} /> {{outlet}} |
Output: Visit localhost:4200/mapBy2 to view the output
Reference: https://api.emberjs.com/ember/4.4/classes/Ember.NativeArray/methods/mapBy?anchor=mapBy