极客教程Ember.js 组件的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是最广泛使用的前端应用程序框架之一。它旨在加快开发速度，提高工作效率。目前，许多网站都在使用它，包括Square、Discourse、Groupon、Linked In、Live Nation、Twitch和Chipotle等。
get()方法 用于从对象中获取属性的值。该方法类似于object.keyName，并且支持计算属性和unknownProperty处理程序。
语法：
get( keyName );JavaScript
参数:
- keyName： 要获取的属性名称。
返回值： 如果键不存在，则该方法返回属性值或undefined。
安装和运行Ember.js的步骤：
步骤1： 要运行以下示例，您需要拥有一个Ember项目。要创建一个项目，您首先需要安装ember-cli。在终端中编写以下代码：
npm install ember-cliJavaScript
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 enJavaScript
开始服务器，请输入：
ember serveJavaScript
示例1： 输入以下代码生成此示例的路线：
ember generate route get1JavaScript
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));
},
})JavaScript
app/components/arr.hbs
{{page-title "Init"}}
<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}}HTML
app/templates/get1.hbs
<Arr>
<h3>Fruit's List :</h3>
</Arr>HTML
输出：
示例2： 输入以下代码以生成此示例的路由：
ember generate route get2JavaScript
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));
}
})JavaScript
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}}
/>HTML
app/templates/get2.hbs
<Arr2>
<h3>Student's List :</h3>
</Arr2>HTML
输出：
参考： https://api.emberjs.com/ember/4.6/classes/Component/methods/get?anchor=get