极客教程Ember.js EmberArray slice() 方法
Ember.js 是一个开源的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、LinkedIn、Live Nation、Twitch和Chipotle。
slice() 方法用于返回接收器的一部分新数组。
语法:
slice(begin,end)
参数：
- begin： 起始索引。
- end： 结束索引。
返回值： 接收方在开始和结束之间的部分。
步骤1： 要运行以下示例，您需要有一个Ember项目。要创建一个项目，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：
现在您可以通过键入以下代码来创建项目：
ember new <project-name> --lang en
启动服务器，输入：
ember serve
示例1
输入以下代码生成此示例的路由：
ember generate route details
app/routes/details.js
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: 'Patna',
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',
},
];
city;
start;
end;
model() {
return this.details;
}
setupController(controller, model) {
super.setupController(controller, model);
controller.set('details', this.details);
controller.set('someMoreDetails', this.someMoreDetails);
controller.set('city', this.city);
controller.set('start', this.start);
controller.set('end', this.end);
}
}
app/controllers/details.js
import Ember from "ember";
import { any, slice, reverseObjects,
rejectBy } from "@ember/array";
export default Ember.Controller.extend({
actions: {
checkCity(city) {
let res = this.details.any((person) =>
person.city == city);
alert(`Present: ${res ? "YES" : "NO"}`);
},
sliceItems(start, end) {
let tempItems = this.details.slice(start, end);
let str = "";
for (let i = 0; i < tempItems.length; i++)
str += tempItems[i].name + "\n";
alert(str);
},
reverse() {
this.set("details",
this.details.reverseObjects());
},
getFemale() {
let tempItems =
this.details.rejectBy("gender", "M");
let str = "";
for (let i = 0; i < tempItems.length; i++)
str += tempItems[i].name + "\n";
alert(str);
},
pushMoreDetails() {
this.details.pushObjects(this.someMoreDetails);
},
},
});
app/template/details.hbs
{{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 City: </label>
{{input value=this.city}}
</div>
<div>
<input
type="button"
id="check-city"
value="Check"
{{action "checkCity" this.city}}
/>
</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="slice-items"
value="Slice Items"
{{action "sliceItems" this.start this.end}}
/>
</div>
<br /><br />
<input
type="button"
id="push-details"
value="Add More Details"
{{action "pushMoreDetails"}}
/>
<br /><br />
<input type="button" id="reverse" value="Reverse"
{{action "reverse"}} />
<br /><br />
<input
type="button"
id="get-female"
value="Get Female"
{{action "getFemale"}}
/>
输出： 访问 localhost:4200/details 查看输出：
示例2
输入以下代码生成此示例的路线：
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',
];
itemString;
itemList;
start;
end;
helper(itemString) {
this.itemList = itemString.split(',');
for (let i = 0; i < this.itemList.length; i++)
this.itemList[i] = this.itemList[i].trim();
return this.itemList;
}
model() {
return this.partyItems;
}
setupController(controller, model) {
this._super(controller, model);
controller.set('helper', this.helper);
controller.set('partyItems', this.partyItems);
controller.set('itemString', this.itemString);
controller.set('itemList', this.itemList);
controller.set('start', this.start);
controller.set('end', this.end);
}
}
app/controllers/party.js
import Ember from "ember";
import {
objectsAt,
removeObject,
removeObjects,
slice,
reverseObjects,
setObjects,
reject,
} from "@ember/array";
export default Ember.Controller.extend({
actions: {
getItems(itemString) {
this.itemList = this.helper(itemString);
for (let i = 0; i < this.itemList.length; i++)
this.itemList[i] =
parseInt(this.itemList[i]);
let tempItems =
this.partyItems.objectsAt(this.itemList);
let str = "";
for (let i = 0; i < tempItems.length; i++)
str += tempItems[i] + "\n";
alert(str);
},
removeItems(itemString) {
this.itemList = this.helper(itemString);
if (this.itemList.length == 1)
this.partyItems.removeObject(this.itemList[0]);
else this.partyItems.removeObjects(this.itemList);
this.set("itemString", "");
},
sliceItems(start, end) {
let tempItems = this.partyItems.slice(start, end);
let str = "";
for (let i = 0; i < tempItems.length; i++)
str += tempItems[i] + "\n";
alert(str);
},
reverseItems() {
this.set("partyItems",
this.partyItems.reverseObjects());
},
replaceItems(itemString) {
this.partyItems.setObjects(this.helper(itemString));
},
findMultiwordItems() {
let reqItem = this.partyItems.reject(
(item) => item.split(" ").toArray().length == 1
);
alert(reqItem);
},
},
});
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 Items: </label>
{{input value=this.itemString}}
</div>
<div>
<input
type="button"
id="remove-item"
value="Remove Items"
{{action "removeItems" 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="slice"
value="Slice"
{{action "sliceItems" this.start this.end}}
/>
</div>
<br /><br />
<div>
<label>Enter Indices: </label>
{{input value=this.itemString}}
</div>
<div>
<input
type="button"
id="get-item"
value="Get Items"
{{action "getItems" this.itemString}}
/>
</div>
<br /><br />
<div>
<label>Enter Items: </label>
{{input value=this.itemString}}
</div>
<div>
<input
type="button"
id="replace-item"
value="Replace Items"
{{action "replaceItems" this.itemString}}
/>
</div>
<br /><br />
<input
type="button"
id="reverse-items"
value="Reverse"
{{action "reverseItems"}}
/>
<br /><br />
<input
type="button"
id="find-items"
value="Find"
{{action "findMultiwordItems"}}
/>
{{outlet}}
输出： 访问 localhost:4200/party 查看输出结果：
参考： https://api.emberjs.com/ember/4.6/classes/EmberArray/methods/