Embeer.js ArrayProxy 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() 方法用于获取列表中与传递的值匹配的第一个值。

用法:

findBy( key, value );

参数：

key: 它是我们想要其值的属性的名称。
value: 它是我们要测试其值的键的值。

返回值：其他找到的项目返回‘undefined’。

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 findBy1

应用程序/路线/findBy1.js


import Route from '@ember/routing/route'; 
import { findBy } from '@ember/array'; 
  
export default class FruitsRoute extends Route { 
    item1 = [ 
        { 
            name: 'Apple', 
            isFruit: true, 
            color: 'red', 
        }, 
        { 
            name: 'Grapes', 
            isFruit: true, 
            color: 'green', 
        }, 
        { 
            name: 'Mango', 
            isFruit: true, 
            color: 'yellow', 
        }, 
        { 
            name: 'Watermelon', 
            isFruit: true, 
            color: 'red', 
        }, 
        { 
            name: 'Orange', 
            isFruit: true, 
            color: 'orange', 
        } 
    ]; 
    item2 = [ 
        { 
            name: 'Lady Finger', 
            isFruit: false, 
            color: 'green', 
        }, 
        { 
            name: 'Brinjal', 
            isFruit: false, 
            color: 'purple', 
        }, 
        { 
            name: 'Potato', 
            isFruit: false, 
            color: 'brown', 
        }, 
        { 
            name: 'Onion', 
            isFruit: false, 
            color: 'violer', 
        }, 
    ]; 
    model() { 
        return this.item1; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('item1', this.item1); 
        controller.set('item2', this.item2); 
    } 
}

应用程序/控制器/findBy1.js


import Ember from 'ember'; 
import { removeAt, unshiftObjects, objectAt,  
    uniqBy, find } from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        Find_item(data) { 
            let foo = this.item1.findBy('name', data); 
            alert(foo ? `${foo.name} present in list` :  
                'No items not present in list'); 
        }, 
        AddItems() { 
            this.item1.addObjects(this.item2); 
        } 
  
    }, 
});

应用程序/模板/findBy1.hbs


{{page-title "findBy"}} 
<h2>List of Item </h2> 
<table> 
    <tr> 
          <th>Name</th> 
        <th>Fruit</th> 
        <th>Color</th> 
      </tr> 
      {{#each @model as |Eatable|}} 
    <tr> 
          <td>{{Eatable.name}}</td> 
          <td>{{Eatable.isFruit}}</td> 
          <td>{{Eatable.color}}</td> 
    </tr> 
      {{/each}} 
</table> 
<br /> 
<div> 
    <label>Enter Quantity: </label> 
      {{input value=this.temp}} 
</div> 
<input 
    type="button"
      id="greet"
      value="Find Item"
      {{action "Find_item" this.temp}} 
/> 
<br /><br /> 
<br /><br /> 
<input type="button" id="add-items" 
    value="Add Items" {{action "AddItems"}} /> 
{{outlet}}

输出：访问 localhost:4200/findBy1 查看输出

Ember.js ArrayProxy findBy 方法

示例 2：键入以下代码以生成本示例的路由：

ember generate route findBy2

应用程序/路线/findBy2.js


import Route from '@ember/routing/route'; 
  
class student { 
    name = null; 
    gender = null; 
    clas = null; 
    grade = null; 
    constructor(name, gender, clas, grade) { 
        this.name = name; 
        this.gender = gender; 
        this.clas = clas; 
        this.grade = grade; 
    } 
} 
  
export default class StudentsRoute extends Route { 
    students = [ 
        new student('Aakash', 'M', 10, 'P'), 
        new student('Soniya', 'F', 8, 'F'), 
        new student('Esnoor', 'M', 9, 'P'), 
        new student('Isha', 'F', 11, 'P'), 
        new student('Doman', 'M', 12, 'F'), 
        new student('Lolu', 'M', 10, 'P'), 
        new student('Satyam', 'M', 10, 'F'), 
    ]; 
    temp1 = ['name', 'gender', 'class', 'grade']; 
    temp2; 
    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/控制器/findBy2.js


import Ember from 'ember'; 
import { mapBy, every } from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        setattr(temp) { 
            this.set('temp', temp); 
        }, 
        find_Data(data, data1) { 
            [data, data1] = data == 'class' ?  
                ['clas', JSON.parse(data1)] : [data, data1]; 
            let foo = this.students.findBy(data, data1); 
            alert(foo ? `${foo.name} is from class ${foo.clas}` 
                : `No One present`); 
        }, 
    }, 
});

应用程序/模板/findBy2.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.clas}}</td> 
          <td>{{detail.grade}}</td> 
    </tr> 
      {{/each}} 
</table> 
<br /> 
<div> 
    <label>Select Attribute: </label> 
      <select onchange={{action "setattr" 
        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/findBy2 查看输出

Ember.js ProxyArray findBy 方法

参考：https://api.emberjs.com/ember/2.14/classes/Ember.Array/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 ArrayProxy 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。