Ember.js ArrayProxy replace()方法

Ember.js 是一种开源的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等。

replace()方法 用于替换数组中的某些元素。

语法：

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： 应该添加到数组中的项目数组，可以包含零个或多个项目

返回值： 不返回任何内容。

步骤1： 为了运行以下示例，你将需要一个 Ember 项目。要创建一个项目，你需要先安装 Ember CLI。在终端中输入以下代码：

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，请键入：

ember serve

示例1： 输入以下代码以生成此示例的路由：ember generate route party

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",
        "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);
    }
}

app/controllers/party.js

import Ember from "ember";
import {
    without,
    toArray,
    unshiftObject,
    unshiftObjects,
    removeAt,
    objectAt,
    find,
    replace,
    unique,
} 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.unique();
            let str = "";
            for (let i = 0; i < tempItems.length; i++)
                str += tempItems[i] + "\n";
            alert(str);
            this.set("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>
    <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 查看输出结果

Ember.js ArrayProxy replace()方法

示例2： 输入以下代码以生成此示例的路由：

ember generate route notepad

app/routes/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);
    }
}

app/controllers/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", "");
        },
    },
});

app/模板/记事本.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}}