Ember.js Ember.NativeArray insertAt() 方法

Ember.js 是一个开源的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并提高生产力。目前，它被许多网站使用，包括Square、Discourse、Groupon、Linked In、Live Nation、Twitch和Chipotle。

insertAt() 方法用于在数组的特定位置插入对象。

语法：

insertAt(idx,obj)

参数：

idx：插入操作将发生的索引位置。
obj：要插入的对象。

返回值： 接收方。

步骤1：要运行以下示例，您需要先拥有一个ember项目。创建一个项目，您需要先安装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来创建项目：

ember new <project-name> --lang en

要启动服务器，请输入：

ember serve

示例1 ：输入以下代码生成此示例的路线：

ember generate route list

app/routes/list.js

import Route from "@ember/routing/route"; 
  
export default class ListRoute extends Route { 
    list = ["a", "a", "v", "c", "c", "a", 
        "d", "q", "b", "z", "a"]; 
    item; 
    idx; 
    model() { 
        return this.list; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set("list", this.list); 
        controller.set("item", this.item); 
        controller.set("idx", this.idx); 
    } 
}

app/controllers/list.js

import Ember from "ember"; 
import { 
   clear, insertAt, indexOf, lastIndexOf, 
   includes 
} from "@ember/array"; 
  
export default Ember.Controller.extend({ 
   actions: { 
       insertItem(item, idx) { 
           this.list.insertAt(idx, item); 
       }, 
       getLastIndex(item) { 
           let res = this.list.lastIndexOf(item); 
           alert(res); 
       }, 
       getFirstIndex(item) { 
           let res = this.list.indexOf(item); 
           alert(res); 
       }, 
       clearList() { 
           this.list.clear(); 
       }, 
       contains(item) { 
           let res = this.list.includes(item); 
           alert(`The list  ${res ? "" : "does not"} contains$ {item}`); 
       }, 
   }, 
});

app/template/list.hbs

{{page-title "List"}} 
<h3>Here is a list of Items: </h3> 
<ul> 
    {{#each @model as |i|}} 
        <li>{{i}}</li> 
      {{/each}} 
</ul> 
<br /><br /> 
<div> 
    <label>Enter Item: </label> 
      {{input value=this.item}} 
</div> 
<div> 
    <label>Enter Index: </label> 
      {{input value=this.idx}} 
</div> 
<div> 
<input
    type="button"
    id="insert-item"
    value="Insert Item"
    {{action "insertItem" this.item this.idx}} 
/> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Item: </label> 
      {{input value=this.item}} 
</div> 
<div> 
    <input
        type="button"
        id="first-index-item"
        value="Get First Index"
        {{action "getFirstIndex" this.item}} 
      /> 
</div> 
<div> 
    <input
        type="button"
        id="last-index-item"
        value="Get Last Index"
        {{action "getLastIndex" this.item}} 
      /> 
</div> 
<div> 
    <input
        type="button"
        id="contains-item"
        value="Contains?"
        {{action "contains" this.item}} 
      /> 
</div> 
<br /><br /> 
<input type="button" id="clear-items" value="Clear" 
    {{action "clearList"}} /> 
{{outlet}}

输出：

访问 localhost:4200/list 查看输出
Ember.js Ember.NativeArray insertAt() 方法

示例2： 输入以下代码以生成此示例的路由：

ember generate route party

app/routes/party.js

import Route from "@ember/routing/route"; 
  
export default class PartyRoute extends Route { 
    partyItems = [ 
        "Digital Camera", 
        "Jugs, cups & straws", 
        "Cold Drink", 
        "Balloons", 
        "Scissors", 
        "Wine", 
        "Cold Drink", 
        "Table Confetti", 
        "Party Hats", 
        "Wine", 
        "Napkins", 
        "Party Plates", 
        "Speakers", 
        "Wine", 
        "Music System", 
        "Cold Drink", 
        "Cups", 
    ]; 
    item; 
    idx; 
    model() { 
        return this.partyItems; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set("partyItems", this.partyItems); 
        controller.set("item", this.item); 
        controller.set("idx", this.idx); 
    } 
}

app/controllers / party.js

import Ember from "ember"; 
import { insertAt, indexOf, lastIndexOf, includes } 
    from "@ember/array"; 
  
export default Ember.Controller.extend({ 
    actions: { 
        insertItem(item, idx) { 
            this.partyItems.insertAt(idx, item); 
        }, 
        getLastIndex(item) { 
            let res = this.partyItems.lastIndexOf(item); 
            alert(res); 
        }, 
        getFirstIndex(item) { 
            let res = this.partyItems.indexOf(item); 
            alert(res); 
        }, 
        clearpartyItems() { 
            this.partyItems.clear(); 
        }, 
        contains(item) { 
            let res = this.partyItems.includes(item); 
            alert(`The partyItems  ${res ? "" : "does not"} contains$ {item}`); 
        }, 
    }, 
});

app/template/party.hbs

{{page-title "Party"}} 
<h3>Here is a list of items: </h3> 
<ul> 
    {#each @model as |party|}} 
    <li>{{party}}</li> 
    {{/each}} 
</ul> 
<br /><br /> 
<div> 
    <label>Enter Item: </label> 
    {{input value=this.item}} 
</div> 
<div> 
    <label>Enter Index: </label> 
    {{input value=this.idx}} 
</div> 
<div> 
    <input type="button" id="insert-item" 
           value="Insert Item" 
           {{action "insertItem" this.item this.idx}} /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Item: </label> 
    {{input value=this.item}} 
</div> 
<div> 
    <input type="button" id="first-index-item" 
           value="Get First Index" 
           {{action "getFirstIndex" this.item}} /> 
</div> 
<div> 
    <input type="button" id="last-index-item" 
           value="Get Last Index" 
           {{action "getLastIndex" this.item}} /> 
</div> 
<div> 
    <input type="button" id="contains-item" 
           value="Contains?" 
           {{action "contains" this.item}} /> 
</div> 
<br /><br /> 
{{outlet}}

输出： 访问 localhost:4200/party 查看输出

Ember.js Ember.NativeArray insertAt() 方法