极客教程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
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}}
输出： 访问localhost:4200/decrement2查看输出
