Embeer.js EmberArray findBy()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。

findBy() 方法是获取第一个具有与传递值匹配的属性的项目。

用法:

findBy( key, value );

属性：

key: 这是我们要测试的属性的名称。
value: 它是一个可选值，需要针对该键进行测试。

返回值：如果找到则返回返回的项目，否则返回‘undefined’。

安装步骤：

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 find-by1

应用程序/路线/find-by1.js


import Route from '@ember/routing/route'; 
import { classify, w } from '@ember/string'; 
import { pushObject, sortBy } from '@ember/array'; 
  
export default class LanguagesRoute extends Route { 
    name = `Hindi Korean Marathi Telugu Portuguese 
        Turkish Bengali Spanish`; 
    num = `343.9 81.7 83.1 82.0 232.4 82.3 233.7 474`; 
  
    languages = []; 
  
    initLanguages() { 
        this.languages = []; 
        this.name = w(this.name); 
        this.num = w(this.num); 
        for (let i = 0; i < this.name.length; i++) { 
            let obj = new Object(); 
            obj['name'] = classify(this.name[i]); 
            obj['num'] = this.num[i]; 
            this.languages.pushObject(obj); 
        } 
    } 
    temp1; 
    model() { 
        this.initLanguages(); 
        return this.languages; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('languages', this.languages); 
        controller.set('temp1', this.temp1); 
    } 
}

应用程序/controlloers/find-by1.js


import Ember from 'ember'; 
import { mapBy } from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        FindNatives(data1) { 
            let ans = this.languages.findBy('name', data1); 
            alert(`${ans.num} Million people speaks ${ans.name}`); 
        }, 
  
    }, 
});

应用程序/模板/find-by1.hbs


{{page-title "Languages"}} 
<h2>Spoken Languages in the World</h2> 
<table style="border: 2px solid black;padding: 30px;"> 
    <tr> 
        <th>Language</th> 
        <th>Native Speakers (in Millions)</th> 
      </tr> 
          {{#each @model as |language|}} 
            <tr> 
                  <td>{{language.name}}</td> 
                  <td>{{language.num}}</td> 
            </tr> 
          {{/each}} 
</table> 
<br /><br /> 
<div> 
    <label> 
        Enter Language Name for search: 
      </label> 
      {{input value=this.temp1}} 
</div> 
<br /> 
<div> 
    <input 
        type="button"
        id="check-language"
        value="Check Language Speaking Population"
        {{action "FindNatives" this.temp1}} 
      /> 
</div> 
{{outlet}}

输出：访问 localhost:4200/find-by1 查看输出

Ember.js EmberArray findBy 方法

示例 2：键入以下代码以生成本示例的路由：

ember generate route find-by2

应用程序/路线/find-by2.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: 'Esnoor', 
            gender: 'M', 
            class: 9, 
            grade: 'C', 
        }, 
        { 
            name: 'Isha', 
            gender: 'F', 
            class: 11, 
            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: 'Balit', 
            gender: 'M', 
            class: 12, 
            grade: 'F', 
        }, 
        { 
            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', 
        }, 
    ]; 
    temp1 = ['name', 'gender', 'class', 'grade'] 
    temp2; 
    temp; 
    model() { 
        return this.students; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('students', this.students); 
        controller.set('temp', this.temp); 
        controller.set('temp1', this.temp1); 
        controller.set('temp2', this.temp2); 
    } 
}

应用程序/controlloers/find-by2.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); 
        }, 
        find_Data(data, data1) { 
            data1 = (data === 'class') ? 
                JSON.parse(data1) : data1; 
            let ans = this.students.findBy(data, data1); 
            alert(`${ans.name} from Class ${ans.class}`); 
  
        }, 
    }, 
});

应用程序/模板/find-by2.hbs


{{page-title "Student"}} 
<h3>List of Students: </h3> 
<br /><br /> 
<table> 
    <tr> 
        <th>Name</th> 
        <th>Gender </th> 
        <th>Class </th> 
        <th>Grade </th> 
      </tr> 
      {{#each @model as |detail|}} 
    <tr> 
          <td>{{detail.name}}</td> 
          <td>{{detail.gender}}</td> 
          <td>{{detail.class}}</td> 
          <td>{{detail.grade}}</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-student"
        value="Get the First Student"
        {{action "find_Data" this.temp this.temp2}} 
      /> 
</div> 
{{outlet}}

输出：访问 localhost:4200/find-by2 查看输出

Ember.js EmberArray findBy 方法

参考：https://api.emberjs.com/ember/4.6/classes/EmberArray/methods/findBy?anchor=findBy

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 findBy() 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。