Embeer.js Component decrementProperty()用法及代码示例

Ember.js 是一个开源 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是使用最广泛的前端应用框架之一。它的目的是加速开发并提高生产力。目前，它被大量网站使用，包括 Square、Discourse、Groupon、Linked In、Live Nation、Twitch 和 Chipotle。

当属性的值需要减少到一定数量时，使用decrementProperty()方法。

用法:

decrementProperty( keyName, decrement );

参数：

keyName: 它是要递减的属性。
decrement: 它是要减少的值。默认值为 1。

返回值：此方法返回一个新的属性值。

安装和运行 Ember.js 的步骤：

第 1 步：要运行以下示例，您需要有一个 ember 项目。要创建一个，您需要先安装ember-cli。在终端中写入以下代码：

npm install ember-cli

第 2 步：现在您可以通过输入以下代码来创建项目：

ember new <project-name> --lang en

要启动服务器，请键入：

ember serve

示例 1：键入以下代码以生成本示例的路由：

ember generate route decrement1

应用程序/组件/temp.js

Javascript


import Component from '@glimmer/component'; 
import { tracked } from '@glimmer/tracking'; 
import { action, incrementProperty, defineProperty } 
    from '@ember/object'; 
import EmberObject from '@ember/object'; 
  
export default class extends Component { 
    @tracked 
    details = [ 
        EmberObject.create({ 
            name: 'Wilow Lingwood', 
            gender: 'F', 
            class: 8, 
            grade: 'A', 
            pocket_money: 4279, 
        }), 
        EmberObject.create({ 
            name: 'Estele MacIllrick', 
            gender: 'M', 
            class: 9, 
            grade: 'E', 
            pocket_money: 2579, 
        }), 
        EmberObject.create({ 
            name: 'Israel Blackaller', 
            gender: 'M', 
            class: 10, 
            grade: 'A', 
            pocket_money: 9381, 
        }), 
        EmberObject.create({ 
            name: 'Doralyn Sowerbutts', 
            gender: 'F', 
            class: 12, 
            grade: 'A', 
            pocket_money: 4933, 
        }), 
        EmberObject.create({ 
            name: 'Lolly Boynes', 
            gender: 'F', 
            class: 8, 
            grade: 'A', 
            pocket_money: 1988, 
        }), 
        EmberObject.create({ 
            name: 'Lucie Janowski', 
            gender: 'F', 
            class: 11, 
            grade: 'F', 
            pocket_money: 6185, 
        }), 
        EmberObject.create({ 
            name: 'Celene Enticknap', 
            gender: 'F', 
            class: 9, 
            grade: 'A', 
            pocket_money: 7186, 
        }), 
        EmberObject.create({ 
            name: 'Hillier Buchanan', 
            gender: 'M', 
            class: 12, 
            grade: 'A', 
            pocket_money: 844, 
        }), 
        EmberObject.create({ 
            name: 'Flint Chesley', 
            gender: 'M', 
            class: 9, 
            grade: 'B', 
            pocket_money: 3835, 
        }), 
    ]; 
  
    decrement() { 
        this.details.forEach( 
            (value) => value.decrementProperty( 
                'pocket_money', 100) 
        ); 
    } 
}

应用程序/组件/temp.hbs

HTML


{{page-title "Component decrementProperty"}} 
<h3>List of Students: </h3> 
<table> 
    <tr> 
        <th>Name</th> 
        <th>Class</th> 
        <th>Gender</th> 
        <th>Grade</th> 
        <th>Pocket Money</th> 
    </tr> 
    {{#each this.details as |detail|}} 
        <tr> 
            <td>{{detail.name}}</td> 
            <td>{{detail.gender}}</td> 
            <td>{{detail.class}}</td> 
            <td>{{detail.grade}}</td> 
            <td>{{detail.pocket_money}}</td> 
        </tr> 
    {{/each}} 
</table> 
<br /><br /> 
<input
    type="button"
    id="lower-all"
    value="Lower the Pokcet money by 100"
    {{action "decrement"}} 
/>

应用程序/模板/decrement1.hbs

HTML


<Arr>decrementProperty Example</Arr>

输出：

减量属性输出1

示例 2：键入以下代码以生成本示例的路由：

ember generate route decrement2

应用程序/组件/test.js

Javascript


import Component from '@glimmer/component'; 
import { tracked } from '@glimmer/tracking'; 
import { action, incrementProperty, defineProperty }  
    from '@ember/object'; 
import EmberObject from '@ember/object'; 
  
const Food = EmberObject.extend({ 
    toStringExtension() { 
        return this.get('food'); 
    } 
}); 
  
export default class extends Component { 
    @tracked 
    details = [ 
        EmberObject.create({ 
            name: 'Mohan', 
            age: 20, 
            salary: 10000, 
            city: 'Patna', 
            gender: 'M', 
        }), 
        EmberObject.create({ 
            name: 'Sonam', 
            age: 17, 
            salary: 2000, 
            city: 'Mumbai', 
            gender: 'F', 
        }), 
        EmberObject.create({ 
            name: 'Satyam', 
            age: 42, 
            salary: 230000, 
            city: 'Delhi', 
            gender: 'M', 
        }), 
        EmberObject.create({ 
            name: 'Shivam', 
            age: 33, 
            salary: 122200, 
            city: 'Patna', 
            gender: 'M', 
        }), 
        EmberObject.create({ 
            name: 'Ayushi', 
            age: 11, 
            salary: 100, 
            city: 'Jaipur', 
            gender: 'F', 
        }), 
        EmberObject.create({ 
            name: 'Yeshwant', 
            age: 19, 
            salary: 5000, 
            city: 'Chennai', 
            gender: 'M', 
        }), 
        EmberObject.create({ 
            name: 'Siddhant', 
            age: 65, 
            salary: 992130, 
            city: 'Mangalore', 
            gender: 'M', 
        }), 
        EmberObject.create({ 
            name: 'Khushi', 
            age: 10, 
            salary: 230390, 
            city: 'Pune', 
            gender: 'F', 
        }), 
    ]; 
  
    decrement() { 
        this.details.forEach( 
            (value) => value.decrementProperty( 
                'salary', 1000) 
        ); 
    } 
}

应用程序/组件/test.hbs

HTML


{{page-title "Component decrementProperty"}} 
<h3>List of People: </h3> 
<br /> 
<table> 
    <tr> 
        <th>Name</th> 
        <th>Gender</th> 
        <th>Age</th> 
        <th>Salary</th> 
        <th>City</th> 
    </tr> 
    {{#each this.details as |detail|}} 
        <tr> 
            <td>{{detail.name}}</td> 
            <td>{{detail.gender}}</td> 
            <td>{{detail.age}}</td> 
            <td>{{detail.salary}}</td> 
            <td>{{detail.city}}</td> 
        </tr> 
    {{/each}} 
</table> 
<br /><br /> 
<input
    type="button"
    id="get-all"
    value="Lower Salary of All By 1000"
    {{action "decrement"}} 
/>

应用程序/模板/减量.hbs

HTML


<Arr2> 
    DecrementProperty Example 
</Arr2>

输出：

减量属性输出2

参考：https://api.emberjs.com/ember/4.4/classes/Component/methods/decrementProperty?anchor=decrementProperty

相关用法

注：本文由纯净天空筛选整理自nickgulshan大神的英文原创作品 Ember.js Component decrementProperty() Method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。