Embeer.js ArrayProxy filter()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。

filter() 方法用于使用前一个数组的所有项目形成一个新数组，该数组针对回调函数返回 true。

用法:

filter( callback, target );

参数：

callback: 它是针对数组的每个项目进行测试的回调函数。
target: 这是针对回调函数进行测试的项目。

返回值：它返回一个过滤后的数组。

安装和运行 Ember.js 的步骤：

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

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 filter1

应用程序/路线/filter1.js


import Route from '@ember/routing/route'; 
  
export default class WebsitesRoute  
 extends Route { 
    food = [ 
        { 
            food: 'apple', 
            quant: 1.5, 
            Bucket: 1, 
        }, 
        { 
            food: 'Potato', 
            quant: 3, 
            Bucket: 2, 
        }, 
        { 
            food: 'Banana', 
            quant: 2, 
            Bucket: 1, 
        }, 
        { 
            food: 'grapes', 
            quant: 3, 
            Bucket: 2, 
        }, 
        { 
            food: 'Orange', 
            quant: 2, 
            Bucket: 1, 
        }, 
        { 
            food: 'Pine-apple', 
            quant: 1, 
            Bucket: 2, 
        }, 
        { 
            food: 'bean', 
            quant: 3, 
            Bucket: 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); 
    } 
}

应用程序/控制器/filter1.js


import Ember from 'ember'; 
import { filter, reduce, clear } from '@ember/array'; 
  
export default Ember.Controller.extend({ 
  
    actions: { 
        Fiter_item(data) { 
            let foo = this.food.filter((item)  
            => item.quant > JSON.parse(data)); 
            let temp = foo.reduce((acc, item) 
            => acc + item.food + '\n', ''); 
            alert(temp ? temp : "No Item is filtered"); 
  
        }, 
        remove() { 
            this.food.clear(); 
  
        }, 
    }, 
});

应用程序/模板/filter1.hbs


{{page-title "filter"}} 
  
<h2>List of Item with Quantity </h2> 
  
<table> 
    <tr> 
        <th>Name</th> 
        <th>Quantity</th> 
        <th>Bucket</th> 
    </tr> 
    {{#each @model as |Eatable|}} 
        <tr> 
            <td>{{Eatable.food}}</td> 
            <td>{{Eatable.quant}}</td> 
            <td>{{Eatable.Bucket}}</td> 
        </tr> 
    {{/each}} 
</table> 
<br /> 
<div> 
    <label>Enter Quantity: </label> 
    {{input value=this.temp}} 
</div> 
<input 
    type="button"
    id="greet"
    value="Filter Item"
    {{action "Fiter_item" this.temp}} 
/> 
  
<br /><br /> 
<input type="button" id="greet" 
value="Remove items" {{action "remove"}} /> 
{{outlet}}

输出：访问 localhost:4200/filter1 查看输出

Ember.js ArrayProxy过滤方法

示例 2：键入以下代码以生成本示例的路由：

ember generate route filter2

应用程序/路线/filter2.js


import Route from '@ember/routing/route'; 
  
export default class StudentsRoute extends Route { 
    students = [ 
        { 
            name: 'Aakash', 
            gender: 'M', 
            class: 10, 
            grade: 'A', 
        }, 
        { 
            name: 'Soniya', 
            gender: 'F', 
            class: 8, 
            grade: 'C', 
        }, 
        { 
            name: 'Sita', 
            gender: 'F', 
            class: 10, 
            grade: 'A', 
        }, 
        { 
            name: 'Ram', 
            gender: 'M', 
            class: 10, 
            grade: 'A', 
        }, 
        { 
            name: 'Esnoor', 
            gender: 'M', 
            class: 9, 
            grade: 'C', 
        }, 
        { 
            name: 'Isha', 
            gender: 'F', 
            class: 19, 
            grade: 'B', 
        }, 
        { 
            name: 'Doman', 
            gender: 'M', 
            class: 12, 
            grade: 'B', 
        }, 
        { 
            name: 'Lolu', 
            gender: 'M', 
            class: 10, 
            grade: 'A', 
        }, 
        { 
            name: 'Lucky', 
            gender: 'M', 
            class: 11, 
            grade: 'F', 
        }, 
        { 
            name: 'Neha', 
            gender: 'F', 
            class: 10, 
            grade: 'B', 
        }, 
        { 
            name: 'Balit', 
            gender: 'M', 
            class: 12, 
            grade: 'F', 
        }, 
        { 
            name: 'Hillier Buchanan', 
            gender: 'M', 
            class: 12, 
            grade: 'A', 
        }, 
        { 
            name: 'Aman', 
            gender: 'M', 
            class: 11, 
            grade: 'B', 
        }, 
        { 
            name: 'Anuj', 
            gender: 'M', 
            class: 12, 
            grade: 'F', 
        }, 
        { 
            name: 'Satyam', 
            gender: 'M', 
            class: 12, 
            grade: 'F', 
        }, 
        { 
            name: 'Aayush', 
            gender: 'M', 
            class: 12, 
            grade: 'C', 
        }, 
    ]; 
    temp2; 
    model() { 
        return this.students; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('students', this.students); 
        controller.set('temp2', this.temp2); 
    } 
}

应用程序/控制器/filter2.js


import Ember from "ember"; 
import { filter, reduce } from "@ember/array"; 
  
export default Ember.Controller.extend({ 
    actions: { 
  
        allFemale() { 
            let temp = this.students.filter((item)  
            => item.gender == 'F'); 
            let foo = temp.reduce((acc, person)  
            => acc + person.name + '\n', '') 
            alert(foo); 
        }, 
        allClass(data) { 
            let ans = ''; 
            let temp = this.students.filter((item)  
            => item.class == JSON.parse(data) ?  
            ans += item.name + '\n' : ''); 
            alert(ans); 
        }, 
    } 
});

应用程序/模板/filter2.hbs


{{page-title "Students"}} 
<h3>List of Students: </h3> 
<br /><br /> 
<table> 
    <tr> 
        <th>Name</th> 
        <th>Class</th> 
        <th>Gender</th> 
        <th>Grade</th> 
    </tr> 
    {{#each @model as |student|}} 
    <tr> 
        <td>{{student.name}}</td> 
        <td>{{student.class}}</td> 
        <td>{{student.gender}}</td> 
        <td>{{student.grade}}</td> 
    </tr> 
    {{/each}} 
</table> 
  
<br /><br/> 
<div> 
    <label>Enter Class: </label> 
    {{input value=this.temp2}} 
</div> 
<br/> 
<input 
    type="button"
    id="all-class"
    value="All are in Same class"
    {{action "allClass" this.temp2}} 
/> 
<br/><br /> 
<input 
    type="button"
    id="all-female"
    value="All are Female"
    {{action "allFemale"}} 
/> 
{{outlet}}

输出：访问 localhost:4200/filter2 查看输出

Ember.js ArrayProxy过滤方法

参考：https://api.emberjs.com/ember/4.4/classes/ArrayProxy/methods/filter?anchor=filter

相关用法

注：本文由纯净天空筛选整理自jeemains0neet大神的英文原创作品 Ember.js ArrayProxy filter() 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。