Ember.js ArrayProxy filter() 方法

Ember.js 是一个开源的JavaScript框架，用于开发基于模型-视图-控制器（MVC）架构的大型客户端Web应用程序。Ember.js 是最广泛使用的前端应用程序框架之一。它被设计用于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。

filter() 方法用于生成一个新数组，该数组包含所有对回调函数返回 true 的前一个数组的项。

语法:

filter( callback, target );

参数：

callback： 这是要对数组的每个项进行测试的回调函数。
target： 这是要针对回调函数进行测试的项。

返回值： 它返回一个过滤后的数组。

安装并运行Ember.js的步骤：

要运行下面的示例，您需要有一个Ember项目。要创建一个项目，首先需要安装ember-cli。在终端中写入以下代码：

npm install ember-cli

现在您可以通过键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

在此示例中输入以下代码以生成路线：

ember generate route filter1

app/routes/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); 
    } 
}

app/controllers/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(); 
  
        }, 
    }, 
});

app/templates/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 查看输出结果

Ember.js ArrayProxy filter() 方法

示例2

输入以下代码以生成此示例的路径：

ember generate route filter2

app/routes/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); 
    } 
}

app/controllers/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); 
        }, 
    } 
});

app/templates/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}}