Embeer.js EmberArray 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() 用于获取过滤后的数组，其中包含为所提供的回调函数返回 true 的项目。

用法:

filter( callback, target );

参数：

callback：它将应用于数组的每个项目的回调函数。
target: 它是回调函数将应用到的对象。

返回值：它返回过滤后的数组。

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

现在您可以通过输入以下代码来创建项目：

ember new <project-name> --lang en

步骤 2：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 Ember from "ember"; 
import { filter } from "@ember/array"; 
  
export default Ember.Controller.extend({ 
    actions: { 
        allPass() { 
            let ans = ''; 
            let temp = this.students.filter((item) => 
            item.grade == 'F'); 
            for (let i = 0; i < temp.length; i++) 
                ans += temp[i].name + '\n'; 
            alert(ans); 
        }, 
        allFemale() { 
            let ans = ''; 
            let temp = this.students.filter((item) => 
            item.gender == 'F'); 
            for (let i = 0; i < temp.length; i++) 
                ans += temp[i].name + '\n'; 
            alert(ans); 
        }, 
        allClass(data) { 
            let ans = ''; 
            let temp = this.students.filter((item) =>  
            item.class == JSON.parse(data)); 
            for (let i = 0; i < temp.length; i++) 
                ans += temp[i].name + '\n'; 
            alert(ans); 
        }, 
    } 
});

应用程序/控制器/filter1.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/模板/filter1.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 /> 
<input 
    type="button"
      id="all-pass"
      value="Failed Student"
      {{action "allPass"}} 
/> 
<br /><br /> 
<input 
    type="button"
      id="all-female"
      value="All are Female"
      {{action "allFemale"}} 
/> 
<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}} 
/> 
{{outlet}}

输出：访问 localhost:4200/filter1 查看输出

Ember.js EmberArray 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'; 
import { } from '@ember/array'; 
  
export default class FruitsRoute extends Route { 
    fruits = [ 
        { 
            name: 'Lady Finger', 
            isFruit: false, 
            color: 'green', 
        }, 
        { 
            name: 'Tomato', 
            isFruit: false, 
            color: 'red', 
        }, 
        { 
            name: 'Apple', 
            isFruit: true, 
            color: 'red', 
        }, 
        { 
            name: 'Potato', 
            isFruit: false, 
            color: 'brown', 
        }, 
        { 
            name: 'Mango', 
            isFruit: true, 
            color: 'yellow', 
        }, 
        { 
            name: 'Bannana', 
            isFruit: true, 
            color: 'yellow', 
        }, 
        { 
            name: 'Cabbage', 
            isFruit: false, 
            color: 'green', 
        }, 
        { 
            name: 'Orange', 
            isFruit: true, 
            color: 'orange', 
        }, 
    ]; 
    temp1 = ['name', 'isFruit', 'color']; 
    temp2; 
    model() { 
        return this.fruits; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('fruits', this.fruits); 
        controller.set('temp1', this.temp1); 
        controller.set('temp2', this.temp2); 
    } 
}

应用程序/控制器/filter2.js


import Ember from 'ember'; 
  
export default Ember.Controller.extend({ 
    vehicle: null, 
    vehicles: Ember.String.w('Tesla Chrysler Toyota'), 
    actions: { 
        selectattr(temp) { 
            this.set('temp', temp); 
        }, 
        filter_Data(data, data1) { 
            if (data == 'isFruit') { 
                let ans = this.fruits.filter((item) => 
                item[data] == JSON.parse(data1)); 
                let temp = ''; 
                for (let i = 0; i < ans.length; i++) 
                    temp += (ans[i].name + '\n') 
                alert(temp); 
            } else { 
                let ans = this.fruits.filter((item) =>  
                item[data] == data1); 
                alert(JSON.stringify(ans)); 
            } 
        }, 
    }, 
});

应用程序/模板/filter2.hbs


{{page-title "Is-Fruits"}} 
<h3>List of Items in Bucket: </h3> 
<br /><br /> 
<table> 
    <tr> 
        <th>Name</th> 
           <th>IsFruit</th> 
        <th>color</th> 
      </tr> 
    {{#each @model as |detail|}} 
    <tr> 
        <td>{{detail.name}}</td> 
          <td>{{detail.isFruit}}</td> 
          <td>{{detail.color}}</td> 
    </tr> 
      {{/each}} 
</table> 
<br /> 
<div> 
    <label>Select Attribute: </label> 
      <select onchange={{action "selectattr" 
        value="target.value"}}> 
    {{#each this.temp1 as |attribute|}} 
        <option value={{attribute}}> 
            {{attribute}} 
        </option> 
    {{/each}} 
    </select> 
</div> 
<br /> 
<div> 
    <label>Enter value for Attribute: </label> 
      {{input value=this.temp2}} 
</div> 
<div> 
    <input 
        type="button"
        id="check-fruit"
        value="Filter Data"
        {{action "filter_Data" this.temp this.temp2}} 
      /> 
</div> 
  
{{outlet}}

输出：访问 localhost:4200/filter2 查看输出

Ember.js EmberArray 过滤方法

参考： https://api.emberjs.com/ember/4.6/classes/EmberArray/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 EmberArray 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。