Ember.js Ember.NativeArray decrementProperty() 方法

Ember.js是一个开源的JavaScript框架，用于开发基于Model-View-Controller (MVC)架构的大型客户端Web应用程序。Ember.js是最常用的前端应用程序框架之一。它旨在加快开发速度并提高生产力。目前，它被许多网站使用，包括Square、Discourse、Groupon、Linked In、Live Nation、Twitch和Chipotle。

decrementProperty() 方法用于将属性设置为当前值减去一些数量。

语法：

decrementProperty( keyName, decrement );

参数:

keyName: 它是我们想要减少值的属性的名称。
decrement: 它是要减少的数量。默认为1。

返回值: 一个新的属性值。

安装和运行Ember.js的步骤:

步骤1: 为了运行下面的示例，您需要有一个Ember项目。要创建一个项目，您需要先安装ember-cli。在终端中写入以下代码：

npm install ember-cli

步骤2： 现在您可以通过键入以下代码片段来创建项目：

ember new <project-name> --lang en

要启动服务器，请键入：

ember serve

示例1： 输入以下代码生成此示例的路由：

ember generate route decrement1

app/routes/decrement1.js

import Route from '@ember/routing/route';
 
export default class WebsitesRoute extends Route {
    food = [
        {
            food: 'apple',
            isFruit: true,
            quant: '1',
        },
        {
            food: 'Potato',
            isFruit: false,
            quant: '2',
        },
        {
            food: 'Banana',
            isFruit: true,
            quant: '1',
        },
        {
            food: 'Burgur',
            isFruit: false,
            quant: '2',
        },
        {
            food: 'Orange',
            isFruit: true,
            quant: '1',
        },
        {
            food: 'sandwitch',
            isFruit: false,
            quant: '2',
        },
        {
            food: 'bean',
            isFruit: false,
            quant: '2',
        },
    ];
    temp;
    model() {
        return this.food;
    }
    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

import Ember from 'ember';
 
export default Ember.Controller.extend({
    value: 0,
    actions: {
        older() {
            this.incrementProperty('value');
        },
        younger() {
            this.decrementProperty('value');
        },
 
        addItem(data, data1, data2) {
            let temp = { 
                food: data, 
                quant: data1, 
                isFruit: data2 
            }
            this.food.addObject(temp)
        },
    },
});

app/templates/decrement1.hbs

{{page-title "decreaseProperty"}}
<h3>List of Item in Buckets</h3>
<table>
    <tr>
        <th> Food Name </th>
        <th>Bucket </th>
        <th>Fruit </th>
      </tr>
      {{#each @model as |website|}}
    <tr>
        <td>{{website.food}}</td>
          <td>{{website.quant}}</td>
          <td>{{website.isFruit}}</td>
    </tr>
      {{/each}}
</table>
<br /><br />
<div>
    <label>Enter Item Name: </label>
      {{input value=this.temp2}}
</div>
<br />
<div>
    <label>Enter Quantity in Kg: </label>
      {{input value=this.value}}
</div>
<input type="button" id="increase" value="+"
    {{action "older"}} />
<input type="button" id="decrease" value="-"
    {{action "younger"}} />
<br />
<br />
<div>
    <label>Item is fruit or not : </label>
      {{input value=this.temp}}
</div>
<br /><br />
<input
    type="button"
      id="all-Fruits"
      value="Add item"
      {{action "addItem" this.temp2 this.value this.temp}}
/>
{{outlet}}

输出： 访问 localhost:4200/decrement1 来查看输出结果

Ember.js Ember.NativeArray decrementProperty() 方法

示例2: 输入以下代码以生成此示例的路由：

ember generate route decrement2

app/controllers/decrement2.js

import Ember from 'ember';
import { decrementProperty }
    from '@ember/array';
 
export default Ember.Controller.extend({
    year: 2022,
    month: 9,
    date: 15,
    actions: {
        olderD() {
            this.incrementProperty('date');
        },
        youngerD() {
            this.decrementProperty('date');
        },
        olderY() {
            this.incrementProperty('year');
        },
        youngerY() {
            this.decrementProperty('year');
        },
        olderM() {
            this.incrementProperty('month');
        },
        youngerM() {
            this.decrementProperty('month');
        },
    },
});

app/templates/decrement2.hbs

{{page-title "DecrementProperty"}}
<h1>Year {{this.year}}</h1>
<input type="button" id="increase"
    value="+" {{action "olderY"}} />
<input type="button" id="decrease"
    value="-" {{action "youngerY"}} />
<hr />
<h1>Month {{this.month}}</h1>
<input type="button" id="increase"
    value="+" {{action "olderM"}} />
<input type="button" id="decrease"
    value="-" {{action "youngerM"}} />
<hr />
<h1>Date {{this.date}}</h1>
<input type="button" id="increaseD"
    value="+" {{action "older"}} />
<input type="button" id="decrease"
    value="-" {{action "youngerD"}} />
{{outlet}}