Embeer.js MutableArray insertAt()用法及代碼示例

Ember.js 是一個開源 JavaScript 框架，用於開發基於 Model-View-Controller (MVC) 架構的大型客戶端 Web 應用程序。 Ember.js是使用最廣泛的前端應用框架之一。它的目的是加速開發並提高生產力。目前，它被大量網站使用，包括 Square、Discourse、Groupon、Linked In、Live Nation、Twitch 和 Chipotle。

insertAt()方法用於將對象插入到數組中的特定位置。

用法:

insertAt(idx,obj)

參數：

idx:將發生插入操作的索引。
obj:要插入的對象。

返回值：收件人。

第 1 步：要運行以下示例，您需要有一個 ember 項目。要創建一個，您需要先安裝ember-cli。在終端中寫入以下代碼：

npm install ember-cli

第 2 步：現在您可以通過輸入以下代碼來創建項目：

ember new <project-name> --lang en

要啟動服務器，請鍵入：

ember serve

示例 1：鍵入以下代碼以生成本示例的路由：

ember generate route list

應用程序/路線/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); 
    } 
}

應用程序/控製器/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}`); 
        }, 
    }, 
});

應用程序/模板/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}}

輸出：訪問 localhost:4200/list 查看輸出

示例 2：鍵入以下代碼以生成本示例的路由：

ember generate route party

應用程序/路線/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); 
    } 
}

應用程序/控製器/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}`); 
        }, 
    }, 
});

應用程序/模板/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}}

輸出：訪問 localhost:4200/party 查看輸出

參考： https://api.emberjs.com/ember/4.4/classes/MutableArray/methods

相關用法

注：本文由純淨天空篩選整理自aayushmohansinha大神的英文原創作品 Ember.js MutableArray insertAt() Method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。