Embeer.js ArrayProxy cacheFor()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。

ArrayProxy 的 cacheFor() 方法用于获取计算属性的缓存值(如果存在)。此方法帮助我们在不调用属性的情况下检查计算属性的值。

句法：

this.object.cacheFor( keyName );

参数：

keyName: 它是我们想要其计算属性值的属性的名称。

返回：它返回计算属性的缓存值(如果存在)。

安装和运行 Ember.js 的步骤：

步骤 1：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 test1

应用程序/路线/test1.js

Javascript


import Route from '@ember/routing/route'; 
import { computed } from '@ember/object'; 
import ArrayProxy from '@ember/object/proxy'; 
  
const Employee = ArrayProxy.extend({ 
    toStringExtension() { 
        return this.get('name'); 
    }, 
    fullName: computed('firstName', 'lastName', 
        function () { 
            return this.get('firstName') + ' '
                + this.get('lastName'); 
        }) 
}); 
  
export default class DetailsRoute extends Route { 
    person; 
    createPerson() { 
        let person = Employee.create({ 
            firstName: 'Sam', 
            lastName: 'Snehil', 
            age: 32, 
            mobile: '837483837847', 
            country: 'India', 
            language: 'Tamil', 
            salary: 34000, 
            gender: 'M', 
            zipCode: '476384', 
        }); 
        return person 
    } 
  
    model() { 
        this.person = this.createPerson(); 
        return this.person 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('person', this.person); 
    } 
}

应用程序/控制器/test1.js

Javascript


import Ember from 'ember'; 
import EmberObject from '@ember/object'; 
  
export default Ember.Controller.extend({ 
  
    actions: { 
        store() { 
            let temp = this.person.cacheFor('fullName'); 
            console.log(temp + ' Cached From ' + 
                this.person.toString()) 
        } 
    } 
});

应用程序/模板/test1.hbs

HTML


{{page-title "ArrayProxy"}} 
<table> 
    <h1>Employee's Details: </h1> 
    <div><b>Name:</b> {{this.person.fullName}}</div> 
    <div><b>Gender:</b> {{this.person.gender}}</div> 
    <div><b>Country:</b> {{this.person.country}}</div> 
    <div><b>Salary:</b> {{this.person.salary}}</div> 
    <div><b>Zip Code:</b> {{this.person.zipCode}}</div> 
    <div><b>Language Speaks:</b>{{this.person.language}}</div> 
    <div><b>Mobile No.:</b>{{this.person.mobile}}</div> 
    <div><b>Age:</b> {{this.person.age}}</div> 
</table> 
  
<br /><br/> 
<input
    type="button"
    id="Cache"
    value="Cache the Property"
    {{action 'store'}} 
> 
{{outlet}}

输出：

缓存用于输出1

示例 2：键入以下代码以生成本示例的路由：

ember generate route test2

应用程序/路线/test2.js

Javascript


import Route from '@ember/routing/route'; 
import ArrayProxy from '@ember/object'; 
import { computed } from '@ember/object'; 
  
const Person = ArrayProxy.extend({ 
    Grade: computed('marks', function () { 
        let temp = this.get('marks') 
        return temp > 80 ? 'A' : temp > 70 ? 'B' : 
            temp > 60 ? 'C' : 'D'; 
    }), 
    toStringExtension() { 
        return this.get('name'); 
    }, 
}); 
  
export default class StudentsRoute extends Route { 
    person = Person.create({ 
        name: 'Umesh dubey', 
        gender: 'M', 
        class: 10, 
        marks: 83, 
        mobile: '8399384948', 
        Roll_No: '1029394', 
        Branch: 'Commerce', 
    }) 
  
    model() { 
        return this.person; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('person', this.person); 
    } 
}

应用程序/控制器/test2.js

Javascript


import Ember from 'ember'; 
import EmberObject from '@ember/object'; 
import { cacheFor, destroy } from '@ember/object'; 
  
export default Ember.Controller.extend({ 
    actions: { 
  
        storeNonCompute() { 
            let temp = this.person.cacheFor('name'); 
            console.log(temp + ' is Cached From ' + 
                this.person.toString()) 
        }, 
        storeCompute() { 
  
            let temp = this.person.cacheFor('Grade'); 
            console.log(`'${temp}'` + ' Grade is Cached2 From ' + 
                this.person.toString()) 
        }, 
  
    } 
});

应用程序/模板/test2.js

HTML


{{page-title "ArrayProxy"}} 
<table> 
    <h1>Student's Details:</h1> 
    <div><b>Name:</b> {{this.person.name}}</div> 
    <div><b>Gender:</b> {{this.person.gender}}</div> 
    <div><b>Class:</b> {{this.person.class}}</div> 
    <div><b>Mobile:</b> {{this.person.mobile}}</div> 
    <div><b>Grade:</b> {{this.person.Grade}}</div> 
    <div><b>Marks:</b> {{this.person.marks}}</div> 
    <div><b>Branch:</b> {{this.person.Branch}}</div> 
      
  
</table> 
<br /><br/> 
<input
    type="button"
    id="CacheFor"
    value="Cache the Non Computed Property"
    {{action 'storeNonCompute'}} 
/><br /><br/> 
<input
    type="button"
    id="CacheFor"
    value="Cache the computed Property"
    {{action 'storeCompute'}} 
/> 
{{outlet}}

输出：

缓存输出2

参考：https://api.emberjs.com/ember/4.9/classes/ArrayProxy/methods/cacheFor?anchor=cacheFor

相关用法

注：本文由纯净天空筛选整理自satyam00so大神的英文原创作品 Ember.js ArrayProxy cacheFor() 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。