Ember.js HashLocation 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，旨在加快开发速度和增加生产力。目前，许多网站都在使用Ember.js，包括Square、Discourse、Groupon、Linked In、Live Nation、Twitch和Chipotle。

get() 方法用于从对象中获取属性的值。该方法与object.keyName相同，支持计算属性和unknownProperty处理程序。

语法:

get( keyName );

参数：

• key： 要检索的属性名称。

返回值： 如果键不存在，则返回属性值或未定义。

安装和运行Ember.js的步骤：

步骤1： 要运行以下示例，您需要拥有一个Ember项目。首先需要安装ember-cli。在终端中写入以下代码：

npm install ember-cli

步骤2： 现在，您可以通过输入以下代码片段来创建项目：

ember new <project-name> --lang en

启动服务器的方法是输入：

ember server

示例1： 输入下面的代码以生成此示例的路由：

ember generate route get1

app/components/arr.js

import Component from '@glimmer/component';
import Ember from 'ember';
import EmberObject from '@ember/object';
import { action, without, set, get } from '@ember/object';
 
const Fruit = EmberObject.extend({
    init() {
        alert(`${this.get('name')} is in list Now`);
    }
});
export default Ember.Component.extend({
 
    fruits: [
        {
            'name': 'Lady Finger',
            'isFruit': false,
            'color': 'green'
        },
        {
            'name': 'Brinjal',
            'isFruit': false,
            'color': 'purple'
        },
        {
            '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'
        }
    ],
 
 
@action
insertItem(data, data1, data2) {
    let temp = Fruit.create({
        name: data,
        isFruit: data1,
        color: data2
    });
    this.fruits.addObject(temp);
},
@action
removeItem(data) {
    let temp = this.fruits.find((item) => item.color == data)
    this.fruits.set('[]', this.fruits.without(temp));
},
 
 
})

app/components/arr.hbs

<h3>{{yield}}</h3>
<table>
    <tr>
        <th>Name</th>
        <th>Fruit</th>
        <th>Color</th>
      </tr>
      {{#each this.fruits as |detail|}}
        <tr>
              <td>{{detail.name}}</td>
              <td>{{detail.isFruit}}</td>
              <td>{{detail.color}}</td>
        </tr>
  {{/each}}
</table>
<br /><br />
<div>
    <label>Enter Fruit Name: </label>
      {{input value=this.item1}}
</div><br />
<div>
    <label>Item is Fruit: </label>
      {{input value=this.item2}}
</div><br />
<div>
    <label>Enter Fruit color: </label>
      {{input value=this.item3}}
</div><br />
<div>
    <input
        type="button"
        id="insert-item"
        value="Insert Fruit"
        {{action "insertItem" this.item1 this.item2 this.item3}}
  />
</div>
<br />
<div>
    <label>Enter Fruit color: </label>
      {{input value=this.item4}}
</div><br />
<div>
    <input
        type="button"
        id="remove-item"
        value="Remove Fruit"
        {{action "removeItem" this.item4}}
      />
</div>
{{outlet}}

app/templates/get1.hbs

<Arr>
    <h3>Fruit's List :</h3>
</Arr>

输出：

示例2： 输入以下代码以生成此示例的路由：

ember generate route get2

app/components/arr2.js

import Component from '@glimmer/component';
import { tracked } from '@glimmer/tracking';
import { action } from '@ember/object';
import Ember from 'ember';
 
let Student = Ember.Object.extend({
    // these will be supplied by `create`
    firstName: null,
    lastName: null,
 
    init() {
        alert(`{this.get('Name')} is Listed`);
    },
    fullName: Ember.computed('firstName', 'lastName', function () {
        return `{this.firstName} {this.lastName}`;
    }),
 
    Changed: Ember.observer('fullName', function () {
        console.log(`fullName changed to:{this.fullName}`);
    }),
});
 
export default Ember.Component.extend({
    students: [{
        Name: 'Balit',
        skill: 'Python',
        Id: 'stu2',
    },
    {
        Name: 'Permu',
        skill: 'PHP',
        Id: 'stu0',
    },
    {
        Name: 'Sam',
        skill: 'R',
        Id: 'stu1',
    },
    {
        Name: 'Pokhu',
        skill: 'JavaScript',
        Id: 'stu3',
    },
    {
        Name: 'Tanu',
        skill: 'Java',
        Id: 'stu4',
    },
    {
        Name: 'Arabh',
        skill: 'c++',
        Id: 'stu5',
    }], 
@tracked
item3: 'Gulshan',
@tracked
item2: 'Angular',
@tracked
item1: 'stu6',
@tracked
item4: 'Sam',
 
@action
print(data1, data2, data3) {
    let temp = Student.create({
        Name: data1,
        skill: data2,
        Id: data3
    });
    this.students.addObject(temp);
},
@action
remove(data1) {
    let temp = this.students.find((item) => item.Name == data1)
    this.students.set('[]', this.students.without(temp));
}
})

app/components/arr2.hbs

{{yield}}
<table>
    <tr>
        <th>Name</th>
        <th>skill</th>
        <th>Id</th>
      </tr>
      {{#each this.students as |detail|}}
        <tr>
            <td>{{detail.Name}}</td>
              <td>{{detail.skill}}</td>
              <td>{{get detail "Id"}}</td>
        </tr>
  {{/each}}
</table>
<br />
<div>
    <label>Enter Student FirstName: </label>
      {{input value=this.item3}}
</div>
<br />
<div>
    <label>Enter Student LastName: </label>
      {{input value=this.item2}}
</div>
<br />
<div>
    <label>Enter Student Id: </label>
      {{input value=this.item1}}
</div>
<br />
<input
    type="button"
      id="set-code"
      value="Update Student details"
      {{action "print" this.item3 this.item2 this.item1}}
/>
<br />
<br />
<div>
    <label>Enter Student Name: </label>
      {{input value=this.item4}}
</div>
<br />
<input
    type="button"
      id="remove-student"
      value="Remove Student"
      {{action "remove" this.item4}}
/>

app/templates/get2.hbs

<Arr2>
    <h3>Student's List :</h3>
</Arr2>

输出:

参考： https://api.emberjs.com/ember/4.6/classes/HashLocation/methods/get?anchor=get