Ember.js Controller get()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是最常用的前端应用程序框架之一。它旨在加快开发速度和提高生产效率。目前，许多网站都在使用它，包括Square、Discourse、Groupon、LinkedIn、Live Nation、Twitch和Chipotle等。

get() 方法用于从对象中检索属性的值。

语法：

get(keyName);

参数：

keyName： 要检索的属性名称。

返回： 属性值或undefined。

安装和运行Ember.js的步骤：

步骤1： 要运行以下示例，您需要一个Ember项目。首先安装ember-cli。在终端中输入以下代码：

npm install ember-cli

步骤2： 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： 输入以下代码以生成此示例的路线：

ember generate route get1

app/routes/get1.js

import Route from '@ember/routing/route'; 
  
export default class StudentsRoute extends Route { 
    p1 = [ 
        'Digital Camera', 
        'Jugs, cups & straws', 
        'Balloons', 
        'Scissors', 
        'Cold Drink', 
        'Table', 
    ]; 
    model() { 
        return this.p1; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('p1', this.p1); 
    } 
}

app/controllers/get1.js

import Ember from 'ember'; 
  
export default Ember.Controller.extend({ 
    value: 'value', 
    init() { 
        this._super(...arguments); 
        this.addObserver('value', this, 'Change'); 
    }, 
  
    Change() { 
        console.log('value changed'); 
    }, 
    actions: { 
        remove(data) { 
            this.p1.set('[]', this.p1.without(data)); 
        }, 
        print() { 
            let ans = this.p1.get('[]'); 
            alert(ans.join('\n')) 
        }, 
    }, 
});

app/templates/get1.hbs

<ul> 
<h3>List is  : </h3> 
    {{#each @model as |party|}} 
        <li>{{party}}</li> 
    {{/each}} 
</ul> 
<br /> 
{{input value=this.value}} 
<br/> 
<input
    type="button"
    id="check-atIndex"
    value="Remove"
    {{action 'remove' this.value}} 
/> 
<br/><br/> 
<input
    type="button"
    id="print-item"
    value="Print All Items"
    {{action 'print' this.value}} 
/>

输出:

Ember.js Controller get()方法

示例2： 输入以下代码来生成这个示例的路由：

ember generate route get2

app/controllers/get2.js

import Controller from '@ember/controller'; 
import { action, find } from '@ember/object'; 
  
import Ember from 'ember'
let Student = Ember.Object.extend({ 
    // these will be supplied by `create` 
    firstName: null, 
    lastName: null, 
  
    fullName: Ember.computed('firstName', 'lastName', function () { 
        return `{this.get('firstName')}{this.get('lastName')}`; 
    }), 
  
    Changed: Ember.observer('fullName', function () { 
        console.log(`fullName changed to: ${this.get('fullName')}`); 
    }) 
}); 
export default class Array2Controller extends Controller { 
  
    stu2 = Student.create({ 
        firstName: 'Kasual', 
        lastName: 'Singh', 
        Id: 'stu2'
    }); 
    stu0 = Student.create({ 
        firstName: 'Yehuda', 
        lastName: 'Katz', 
        Id: 'stu0'
    }); 
    stu1 = Student.create({ 
        firstName: 'Yella', 
        lastName: 'melo', 
        Id: 'stu1'
    }); 
    stu3 = Student.create({ 
        firstName: 'Pokhu', 
        lastName: 'Verma', 
        Id: 'stu3'
    }); 
    value = this.stu3.get('Id'); 
    students = [this.stu0, this.stu1, this.stu2, this.stu3] 
    @action 
    print(data1, data2) { 
        let ans = this.students.findBy('Id', data1) 
        ans.set('firstName', data2) 
    } 
}

app/templates/get2.hbs

<table> 
    <tr> 
        <th>Name</th> 
        <th>Id</th> 
      </tr> 
      {{#each this.students as |detail|}} 
    <tr> 
        <td>{{detail.fullName}}</td> 
          <td>{{get detail "Id"}}</td> 
    </tr> 
      {{/each}} 
</table> 
<br /> 
{{input value=this.value}} 
{{input value=this.value2}} 
<br /> 
<input
    type="button"
      id="set-code"
      value="Update Student details"
      {{action "print" this.value this.value2}} 
/>