Ember.js Observable decrementProperty() Method

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 decrementProperty() method is used to decrease the value of property to some amount.

Syntax:

decrementProperty(keyName,decrement);

Parameters:

• keyName: It is the name of the property whose value we want to decrement.
• decrement: It is the value to which we want to decrement. The default value is 1.

Return Value: This method returns a new property value.

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 decrement1

app/routes/decrement1.js

Javascript

import Route from '@ember/routing/route';
import EmberObject from '@ember/object';

export default class WebsitesRoute extends Route {

    temp;
    model() {
        return "Increment Property";
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        // controller.set('food', this.food);
        controller.set('temp', this.temp);
        controller.set('temp2', this.temp2);
    }
}

app/controllers/decrement1.js

Javascript

import Ember from 'ember';
import EmberObject from '@ember/object';

const Student = EmberObject.extend({
    toStringExtension() {
        return this.get('food');
    }
});
export default Ember.Controller.extend({
    class: 10,
    age: 15,
    student: [
        Student.create({
            Name: 'Aarbh',
            class: 12,
            age: 18,
        }),
        Student.create({
            Name: 'viky',
            class: 9,
            age: 15,
        }),
        Student.create({
            Name: 'Chiku',
            class: 8,
            age: 11,
        }),
        Student.create({
            Name: 'Nikki',
            class: 11,
            age: 17,
        }),
        Student.create({
            Name: 'Ankit',
            class: 8,
            age: 14,
        }),
        Student.create({
            Name: 'Sonam',
            class: 11,
            age: 17,
        }),
        Student.create({
            Name: 'Ravi',
            class: 10,
            age: 16,
        }),
    ],
    actions: {
        older(data) {
            this.incrementProperty(data);
        },
        younger(data) {
            this.decrementProperty(data);
        },

        addItem(data, data1, data2) {

            let temp = Student.create({
                Name: data,
                class: data1,
                age: data2
            });
            alert(temp.toString() + ' Student Added in list');
            this.student.addObject(temp);
        }
    }
});

app/templates/decrement1.hbs

HTML

{{page-title "decrementProperty"}}
<h3>List of Item in Buckets</h3>
<table>
    <tr>
        <th> Name </th>
        <th>Class </th>
        <th>Age </th>
      </tr>
      {{#each this.student as |website|}}
        <tr>
             <td>{{website.Name}}</td>
              <td>{{website.class}}</td>
              <td>{{website.age}}</td>
        </tr>
      {{/each}}
</table>
<br /><br />
<div>
    <label>Enter Student Name: </label>
      {{input value=this.temp2}}
</div>
<br />
<div>
    <label>Enter Age: </label>
      {{input value=this.age}}
</div>
<input
    type="button" id="increase"
    value="+" {{action "older" "age"}} />
<input
    type="button" id="decrease"
    value="-" {{action "younger" "age"}} />
<br />
<br />
<div>
    <label>Enter Class: </label>
      {{input value=this.class}}
</div>
<input type="button" id="increase"
    value="+" {{action "older" "class"}} />
<input type="button" id="decrease"
    value="-" {{action "younger" "class"}} />
<br />
<br />
<br /><br />
<input
    type="button"
      id="all-students"
      value="Add item"
      {{action "addItem" this.temp2 this.class this.age}}
/>
{{outlet}}

Output:

decrementProperty output1

Reference: https://api.emberjs.com/ember/4.4/classes/Observable/methods/decrementProperty?anchor=decrementProperty