Ember.js EmberObject init()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和提高工作效率。目前，它被许多网站使用，包括Square、Discourse、Groupon、LinkedIn、Live Nation、Twitch和Chipotle等。

init() 方法是在对象被实例化时调用的方法。默认情况下，这个方法什么都不做，我们需要根据自己的需求进行重写。

语法:

init(){ // Algorithm };

安装和运行Ember.js的步骤：

步骤1： 要运行下面的示例，您需要有一个Ember项目。要创建一个项目，您首先需要安装ember-cli。在终端中写入以下代码：

npm install ember-cli

步骤2： 现在你可以通过输入以下代码来创建项目：

ember new <project-name> --lang en

步骤3： 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径:

ember generate route init1

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);
}
 
})

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>
{{outlet}}

app/templates/init1.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线：

ember generate route init2

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('firstName')} 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: [
        Student.create({
            firstName: 'Balit',
            lastName: 'stark',
            Id: 'stu2',
        }),
        Student.create({
            firstName: 'Permu',
            lastName: 'scott',
            Id: 'stu0',
        }),
        Student.create({
            firstName: 'Sam',
            lastName: 'melo',
            Id: 'stu1',
        }),
        Student.create({
            firstName: 'Pokhu',
            lastName: 'Verma',
            Id: 'stu3',
        }),
        Student.create({
            firstName: 'Tanu',
            lastName: 'Agrawal',
            Id: 'stu4',
        }),
        Student.create({
            firstName: 'Arabh',
            lastName: 'Singh',
            Id: 'stu5',
        })], 
  @tracked
item3: 'Gulshan',
  @tracked
item2: 'Verma',
  @tracked
item1: 'stu6',
 
  @action
print(data1, data2, data3) {
    let temp = Student.create({
        firstName: data1,
        lastName: data2,
        Id: data3
    });
    this.students.addObject(temp);
}
})

app/components/arr2.hbs

{{yield}}
<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 />
<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}}
/>

app/templates/init2.hbs

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

输出：

参考资料: https://api.emberjs.com/ember/4.6/classes/EmberObject/methods/init?anchor=init