Embeer.js MutableArray replace()用法及代码示例

Ember.js 是一个开源 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是使用最广泛的前端应用框架之一。它的目的是加速开发并提高生产力。目前，许多网站都在使用它，包括 Square、Discourse、Groupon、Linked In、Live Nation、Twitch 和 Chipotle。

replace() 方法用于将数组中的某些元素替换为给定的对象。

用法:

replace(idx,amt,obj)

参数：

idx: 数组中要替换的起始索引
amt: 要从数组中删除的元素数量
obj: 应添加到数组中的项目数组，包含零个或多个

返回：它不返回任何内容。

要运行以下示例，您需要有一个 ember 项目。要创建一个，您需要先安装ember-cli。在终端中写入以下代码：

npm install ember-cli

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，请键入：

ember serve

示例 1：输入以下代码为本示例 embergeneraterouteparty 生成路由

应用程序/路线/party.js


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

应用程序/控制器/party.js


import Ember from "ember"; 
import { 
    without, 
    toArray, 
    unshiftObject, 
    unshiftObjects, 
    removeAt, 
    objectAt, 
    find, 
    replace, 
    uniq, 
} from "@ember/array"; 
  
export default Ember.Controller.extend({ 
    actions: { 
        withoutItem(item) { 
            console.log(item); 
            let tempItems; 
            tempItems = this.partyItems.without(item); 
            let str = ""; 
            for (let i = 0; i < tempItems.length; i++) 
                str += tempItems[i] + "\n"; 
            alert(str); 
            this.set("item", ""); 
        }, 
        addItems(itemString) { 
            this.itemList = itemString.split(",").toArray(); 
            if (this.itemList.length == 1) 
                this.partyItems.unshiftObject(this.itemList[0]); 
            else this.partyItems.unshiftObjects(this.itemList); 
            this.set("itemString", ""); 
        }, 
        removeItems(start, end) { 
            this.partyItems.removeAt(start, end); 
        }, 
        getObject(idx) { 
            alert( 
                `The item at index ${idx} is  
                  ${this.partyItems.objectAt(idx)}` 
            ); 
        }, 
        findMultipleWordItems() { 
            let reqItem = this.partyItems.find( 
                (item) => item.split(" ").toArray().length > 1 
            ); 
            alert(reqItem); 
        }, 
        replaceItem(itemString) { 
            this.itemList = itemString.split(",").toArray(); 
            if (this.itemList.length >  
                this.partyItems.length) alert("Error"); 
            this.partyItems.replace(0,  
                this.itemList.length, this.itemList); 
        }, 
        getUniqueItems() { 
            let tempItems = this.partyItems.uniq(); 
            let str = ""; 
            for (let i = 0; i < tempItems.length; i++) 
                str += tempItems[i] + "\n"; 
            alert(str); 
            this.set("item", ""); 
        }, 
    }, 
});

应用程序/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> 
    <input type="button" id="remove-item" 
        value="Remove Item" 
        {{action 'withoutItem' this.item}}/> 
</div> 
<br/><br/> 
<div> 
    <label>Enter Items: </label> 
    {{input value=this.itemString}} 
</div> 
<div> 
    <input type="button" id="add-item" 
        value="Add Items" 
         {{action 'addItems' this.itemString}}/> 
</div> 
<br/><br/> 
<div> 
    <label>Enter Start Index: </label> 
    {{input value=this.start}} 
</div> 
<div> 
    <label>Enter End Index: </label> 
    {{input value=this.end}} 
</div> 
<div> 
    <input type="button" id="remove-items" 
        value="Remove Items" 
        {{action 'removeItems' this.start this.end}}/> 
</div> 
<br/><br/> 
<div> 
    <label>Enter Index: </label> 
    {{input value=this.idx}} 
</div> 
<div> 
    <input type="button" id="get-item" 
        value="Get Item" {{action 'getObject' this.idx}}/> 
</div> 
<br/><br/> 
<div> 
    <label>Enter Items: </label> 
    {{input value=this.itemString}} 
</div> 
<div> 
    <input type="button" id="replace-item" 
        value="Replace Items" 
        {{action 'replaceItem' this.itemString}}/> 
</div> 
<br/><br/> 
<input type="button" id="get-multiword" 
         value="Get Multiword Items!" 
         {{action 'findMultipleWordItems'}}/> 
<br/><br/> 
<input   type="button" id="get-unique"
         value="Get Unique Items!" 
         {{action 'getUniqueItems'}}/> 
  
  
{{outlet}}

输出：访问 localhost:4200/party 查看输出

示例 2：键入以下代码以生成本示例的路由：

ember generate route notepad

应用程序/路线/notepad.js


import Route from "@ember/routing/route"; 
  
export default class NotepadRoute extends Route { 
    items = []; 
    item; 
    model() { 
        return this.items; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set("items", this.items); 
    } 
}

应用程序/控制器/notepad.js


import Ember from "ember"; 
import { pushObject } from "@ember/array"; 
  
export default Ember.Controller.extend({ 
    actions: { 
        withoutItem(item) { 
            let tempItems; 
            tempItems = this.items.without(item); 
            let str = ""; 
            for (let i = 0; i < tempItems.length; i++) 
                str += tempItems[i] + "\n"; 
            alert(str); 
            this.set("item", ""); 
        }, 
        replaceItem(item) { 
            let itemList = item.split(",").toArray(); 
            if (itemList.length > this.items.length)  
                alert("Error"); 
            this.items.replace(0, itemList.length, itemList); 
        }, 
        addItem(item) { 
            this.items.unshiftObject(item); 
        }, 
        getUniqueItems() { 
            let tempItems = this.items.uniq(); 
            let str = ""; 
            for (let i = 0; i < tempItems.length; i++) 
                str += tempItems[i] + "\n"; 
            alert(str); 
            this.set("item", ""); 
        }, 
    }, 
});

应用程序/模板/notepad.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> 
    <input type="button" id="remove-item" 
           value="Remove Item"
           {{action "withoutItem" this.item}} /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Items: </label> 
    {{input value=this.itemString}} 
</div> 
<div> 
    <input type="button" id="add-item" 
           value="Add Items"
           {{action "addItems" this.itemString}} /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Start Index: </label> 
    {{input value=this.start}} 
</div> 
<div> 
    <label>Enter End Index: </label> 
    {{input value=this.end}} 
</div> 
<div> 
    <input type="button" id="remove-items" 
           value="Remove Items" 
           {{action "removeItems" this.start this.end}} /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Index: </label> 
    {{input value=this.idx}} 
</div> 
<div> 
    <input type="button" id="get-item" value="Get Item" 
           {{action "getObject" this.idx}} /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Items: </label> 
    {{input value=this.itemString}} 
</div> 
<div> 
    <input type="button" id="replace-item" 
           value="Replace Items" 
           {{action "replaceItem" this.itemString}} /> 
</div> 
<br /><br /> 
<input type="button" id="get-multiword" 
           value="Get Multiword Items!"
           {{action "findMultipleWordItems" }} /> 
<br /><br /> 
<input type="button" id="get-unique" 
           value="Get Unique Items!" 
           {{action "getUniqueItems" }} /> 
  
{{outlet}}

输出：访问 localhost:4200/notepad 查看输出：

参考：https://api.emberjs.com/ember/4.4/classes/MutableArray/methods?anchor=replace

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注：本文由纯净天空筛选整理自aayushmohansinha大神的英文原创作品 Ember.js MutableArray replace() Method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。