Ember.js Ember.NativeArray Class

Last Updated : 10 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.

Ember.NativeArray Class: The NativeArray class provides properties that support the MutableArray class and all of its dependent APIs. This enables the native Array to implement them.

Methods: The following is the list of methods for this class:

addObject: This method is used to push an object onto the end of the array if the object is not a present array.
addObjects: This method is used to add a number of objects to the array.
addObserver: This method is used to register an observer for a property.
any: This method is used to check if there are any objects in the target that matches the condition laid by the callback function.
cacheFor: This method is used to get the cached value for an already computed property if it exists.
clear: This method removes all the elements in the array
compact: This method is used to make a copy of an array without null and undefined elements.
decrementProperty: This method is used to set the value of the property to the current value minus some amount.
every: This method is used to check if all objects in the array pass a specific callback function.
filter: This method is used to filter objects in the array according to a specific condition.
filterBy: This method is used to return an array with just the items with the matched property.
find: This method is used to find elements that match the given callback function.
findBy: This method is to get the first item with a property matching the passed value.
forEach: This method is used to run a function on every item of the array.
get: This method is used to retrieve the value of a property from the object.
getEach: This method is used to get all values in the array for a given key.
getProperties: This method is used to get the value of multiple properties at once.
includes: This method is used to check if a given object is present in the array or not.
incrementProperty: This method is used to set the value of the property to the current value plus some amount.
indexOf: This method is used to find the index of a given object in the array.
insertAt: This method is used to insert an object in a specific position in the array.
invoke: This method is used to call the passed method on every object in the receiver that implements it.
isAny: This method is used to check if for anyone the element in the array the passed property resolves to the desired value or not.
isEvery: This method is used to check if, for each element in the array, the passed property resolves to the desired value or not.
lastIndexOf: This method is used to find the last index of an object in the array.
map: This method is used to map all items in the array with a specific function.
mapBy: This method is used to get the value of the named property on all items in the list.
notifyPropertyChange: This method alerts the observer system that a property change has taken place.
objectAt: This method is used to retrieve the object at a given index.
objectsAt: This method is used to fetch items for the given array of indices.
popObject: This method is used to pop objects from an array.
pushObject: This method is used to push an object into an array.
pushObjects: This method is used to push multiple objects into an array.
reduce: This method is used to combine the values of the array into a single value.
reject: This method provides a list of all the enumerated elements for which the provided function returns false.
rejectBy: This method returns an array containing the objects for which the given key’s value is false.
removeAt: This method is used to remove elements on a given index.
removeObject: This method removes all instances of the object from the array.
removeObjects: This method removes each supplied item from the given array.
removeObserver: This method removes any observers you have registered earlier for this object.
replace: This method is used to replace some of the elements in the array with the given objects.
reverseObjects: This method reverses the elements in the array.
set: This method is used to set the key and value to the object.
setEach: This method, for each member, sets the value of the named property.
setObjects: This method replaces the receiver’s content with the argument’s substance.
setProperties: This method sets a number of properties at once.
shiftObject: This method shifts nil, if there are no more, or an object from the array’s beginning.
slice: This method is used to return a new array that is a portion of the receiver.
sortBy: This method is used to sort an array by the specified key.
toArray: This method just transforms the object into a real array.
toggleProperty: This method is used to set the value of the boolean property to the opposite of its current value.
uniq: This method returns a brand-new array with just unique values in it.
uniqBy: This method is used to get objects which unique values for the given key.
unshiftObject: This method is used to add a single object to the start of the array.
unshiftObjects: This method is used to add objects to the front of the array.
without: This method gives back a new array without the given value.

Properties: The following is the list of the properties of this class:

[]: This property is used to get or set the array content.
firstObject: This property is used to retrieve the first object of the array.
lastObject: This property is used to retrieve the last object of the array.
length: This property is used to retrieve the length of the 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: In this example, I am going to demonstrate the use of the functions: without, toArray, unshiftObject, unshiftObjects, removeAt, objectAt, find, replace and uniq.

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

ember generate route party

app/routes/party.js

Javascript

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', 
    ]; 
    item; 
    itemString; 
    itemList; 
    start; 
    end; 
    idx; 
    model() { 
        return this.partyItems; 
    } 
    setupController(controller, model) { 
        this._super(controller, model); 
        controller.set('partyItems', this.partyItems); 
        controller.set('item', this.item); 
        controller.set('itemString', this.itemString); 
        controller.set('itemList', this.itemList); 
        controller.set('start', this.start); 
        controller.set('end', this.end); 
        controller.set('idx', this.idx); 
    } 
}

app/controllers/party.js

Javascript

import Ember from 'ember'; 
import { 
    without, toArray, unshiftObject, unshiftObjects, 
    removeAt, objectAt, find, replace, uniq 
} 
    from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        withoutItem(item) { 
            console.log(item) 
            let tempItems; 
            tempItems = this.partyItems.without(item); 
            let str = ''; 
            for (let i = 0; i < tempItems.length; i++) 
                str += tempItems[i] + '\n'; 
            alert(str); 
            this.set('item', ''); 
        }, 
        addItems(itemString) { 
            this.itemList = itemString.split(',').toArray(); 
            if (this.itemList.length == 1) 
                this.partyItems.unshiftObject(this.itemList[0]); 
            else
                this.partyItems.unshiftObjects(this.itemList); 
            this.set('itemString', ''); 
        }, 
        removeItems(start, end) { 
            this.partyItems.removeAt(start, end); 
        }, 
        getObject(idx) { 
            alert(`The item at index ${idx} is  
            ${this.partyItems.objectAt(idx)}`); 
        }, 
        findMultipleWordItems() { 
            let reqItem = this.partyItems.find((item) => 
                item.split(' ').toArray().length > 1); 
            alert(reqItem); 
        }, 
        replaceItem(itemString) { 
            this.itemList = itemString.split(',').toArray(); 
            if (this.itemList.length > this.partyItems.length) 
                alert('Error'); 
            this.partyItems.replace(0, this.itemList.length, 
                this.itemList); 
        }, 
        getUniqueItems() { 
            let tempItems = this.partyItems.uniq(); 
            let str = ''; 
            for (let i = 0; i < tempItems.length; i++) 
                str += tempItems[i] + '\n'; 
            alert(str); 
            this.set('item', ''); 
        }, 
    }, 
});

app/template/party.hbs

HTML

{{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 Item: </label> 
      {{input value=this.item}} 
</div> 
<div> 
    <input
        type="button"
        id="remove-item"
        value="Remove Item"
        {{action "withoutItem" this.item}} 
      /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Items: </label> 
      {{input value=this.itemString}} 
</div> 
<div> 
    <input
        type="button"
        id="add-item"
        value="Add Items"
        {{action "addItems" 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="remove-items"
        value="Remove Items"
        {{action "removeItems" this.start this.end}} 
      /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Index: </label> 
      {{input value=this.idx}} 
</div> 
<div> 
    <input
        type="button"
        id="get-item"
        value="Get Item"
        {{action "getObject" this.idx}} 
      /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Items: </label> 
      {{input value=this.itemString}} 
</div> 
<div> 
    <input
        type="button"
        id="replace-item"
        value="Replace Items"
        {{action "replaceItem" this.itemString}} 
      /> 
</div> 
<br /><br /> 
<input
    type="button"
      id="get-multiword"
      value="Get Multiword Items!"
      {{action "findMultipleWordItems"}} 
/> 
<br /><br /> 
<input
    type="button"
      id="get-unique"
      value="Get Unique Items!"
      {{action "getUniqueItems"}} 
/> 
{{outlet}}

Output:

Ember.js Ember.NativeArray Class

Example 2: In this example, I am going to demonstrate the use of the function popObject to pop items from the array.

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

ember generate route notepad

app/routes/notepad.js

Javascript

import Route from '@ember/routing/route'; 
  
export default class NotepadRoute extends Route { 
    items = ['Bread', 'Facewash', 'Egg', 'Pen', 'Medicine']; 
    model() { 
        return this.items; 
    } 
    setupController(controller, model) { 
        this._super(controller, model); 
        controller.set('items', this.items); 
    } 
}

app/controllers/notepad.js

Javascript

import Ember from 'ember'; 
import { popObject } from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        removeItem() { 
            if (this.items.length == 0) 
                alert('Item List is Empty'); 
            this.items.popObject(); 
        } 
    } 
})

app/template/notepad.hbs

HTML

{{page-title "Notepad"}} 
<h2>Your Items</h2> 
<ul> 
    {{#each @model as |i|}} 
        <li>{{i}}</li> 
      {{/each}} 
</ul> 
<br /><br /> 
<div> 
    <input
        type="button"
        id="remove-item"
        value="Remove Item"
        {{action "removeItem"}} 
      /> 
</div> 
{{outlet}}