当前位置: 首页>>代码示例 >>用法及示例精选 >>正文

Embeer.js Ember.NativeArray objectAt()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，它被大量网站使用，包括 Square、Discourse、Groupon、Linked In、Live Nation、Twitch 和 Chipotle。

objectAt() 方法用于检索给定索引处的对象。

用法:

objectAt(index)

参数：

  • index:元素的索引。

返回值：所需的对象。

安装和运行 Ember.js 的步骤：

第 1 步：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

第 2 步：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：键入以下代码以生成本示例的路由：

ember generate route party

应用程序/路线/party.js

Javascript


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

Javascript


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.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.js

HTML


{{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 details

应用程序/路线/details.js

Javascript


import Route from '@ember/routing/route';
export default class DetailsRoute extends Route {
    details = [
        {
            name: 'Anubhav',
            mobile: '1298119967',
            city: 'Patna',
            country: 'India',
            gender: 'M',
            zipCode: '800020',
        },
        {
            name: 'Sakshi',
            mobile: '1234567890',
            city: 'Mumbai',
            country: 'India',
            gender: 'F',
            zipCode: '400001',
        },
        {
            name: 'Satyam',
            mobile: '2222222222',
            city: 'Delhi',
            country: 'India',
            gender: 'M',
            zipCode: '110012',
        },
        {
            name: 'Shivam',
            mobile: '1122113322',
            city: 'Bangalore',
            country: 'India',
            gender: 'M',
            zipCode: '530068',
        },
        {
            name: 'Ayushi',
            mobile: '2244668800',
            city: 'Jaipur',
            country: 'India',
            gender: 'F',
            zipCode: '302001',
        },
    ];
    someMoreDetails = [
        {
            name: 'Yeshwant',
            mobile: '1133557799',
            city: 'Chennai',
            country: 'India',
            gender: 'M',
            zipCode: '600001',
        },
        {
            name: 'Siddhant',
            mobile: '9911000000',
            city: 'Mangalore',
            country: 'India',
            gender: 'M',
            zipCode: '574142',
        },
        {
            name: 'Khushi',
            mobile: '8888888888',
            city: 'Pune',
            country: 'India',
            gender: 'F',
            zipCode: '111045',
        },
    ];
    start;
    end;
    idx;
    model() {
        return this.details;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('details', this.details);
        controller.set('someMoreDetails',
            this.someMoreDetails);
        controller.set('start', this.start);
        controller.set('end', this.end);
        controller.set('idx', this.idx);
    }
}

应用程序/控制器/details.js

Javascript


import Ember from 'ember';
import {
    removeAt, unshiftObjects, objectAt,
    uniqBy, find
} from '@ember/array';
export default Ember.Controller.extend({
    actions: {
        removeDetails(start, end) {
            this.details.removeAt(start, end);
        },
        addMoreDetails() {
            this.details.unshiftObjects(this.someMoreDetails);
        },
        getDetail(index) {
            let foo = this.details.objectAt(index);
            alert(foo.name);
        },
        getFirstMaleAndFemalePerson() {
            let foo = this.details.uniqBy('gender').toArray();
            let str = "";
            for (let i = 0; i < foo.length; i++)
                str += foo[i].name + "\n";
            alert(str);
        },
        getFirstMale() {
            let foo = this.details.find(
                (detail) => detail.gender === 'M');
            alert(foo.name);
        },
    },
});

应用程序/模板/details.js

HTML


{{page-title "Details"}}
<h3>List of People: </h3>
<br /><br />
<table>
    <tr>
        <th>Name</th>
        <th>Gender</th>
        <th>Mobile</th>
        <th>City</th>
        <th>Country</th>
        <th>Zip Code</th>
      </tr>
      {{#each @model as |detail|}}
    <tr>
        <td>{{detail.name}}</td>
          <td>{{detail.gender}}</td>
          <td>{{detail.mobile}}</td>
          <td>{{detail.city}}</td>
          <td>{{detail.country}}</td>
          <td>{{detail.zipCode}}</td>
    </tr>
      {{/each}}
</table>
<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-details"
        value="Remove Details"
        {{action "removeDetails" this.start this.end}}
      />
</div>
<br /><br />
<div>
  <label>Enter Index: </label>
  {{input value=this.idx}}
</div>
<div>
    <input
        type="button"
        id="get-detail"
        value="Get detail"
        {{action "getDetail" this.idx}}
      />
</div>
<br /><br />
<input
    type="button"
      id="add-details"
      value="Add More Details"
      {{action "addMoreDetails"}}
/>
<br /><br />
<input
    type="button"
      id="all-male"
      value="Get First Male"
      {{action "getFirstMale"}}
/>
<br /><br />
<input
    type="button"
      id="get"
      value="Get"
      {{action "getFirstMaleAndFemalePerson"}}
/>
{{outlet}}

输出：访问 localhost:4200/details 查看输出

参考：https://api.emberjs.com/ember/4.6/classes/Ember.NativeArray/methods



相关用法


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 Ember.NativeArray objectAt() 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。