什么是将Angular 1提供程序转换为Angular 2的正确方法

Question

有很多关于如何将Angular 1服务和工厂转换为Angular2的文档和示例，但我无法找到关于如何将ng1提供程序转换为等价物的任何内容在ng2中。

例提供商

function AlertService() { 
    this.toast = false; 

    this.$get = getService; 

    this.showAsToast = function(isToast) { 
     this.toast = isToast; 
    }; 

    getService.$inject = ['$timeout', '$sce']; 

    function getService ($timeout, $sce) { 
     var toast = this.toast, 
      alertId = 0, // unique id for each alert. Starts from 0. 
      alerts = [] 

     return { 
      factory: factory, 
      add: addAlert 
     }; 

     function factory(alertOptions) { 
      var alert = { 
       type: alertOptions.type, 
       msg: $sce.trustAsHtml(alertOptions.msg), 
       id: alertOptions.alertId, 
       toast: alertOptions.toast 
      }; 
      alerts.push(alert); 

      return alert; 
     } 

     function addAlert(alertOptions) { 
      alertOptions.alertId = alertId++; 
      var alert = this.factory(alertOptions); 

      return alert; 
     } 

    } 


} 

angular 
    .module('angularApp', []) 
    .provider('AlertService', AlertService); 

什么是在2角的正确相当于这个？

Answer 1

好了，所以我们终于搞明白了感谢https://github.com/jhipster/generator-jhipster/issues/3664#issuecomment-251902173

这里是NG2

import {Injectable, Sanitizer, SecurityContext} from '@angular/core'; 

@Injectable() 
export class AlertService { 

    private alertId: number; 
    private alerts: any[]; 

    constructor(private sanitizer: Sanitizer, private toast: boolean) { 
     this.alertId = 0; // unique id for each alert. Starts from 0. 
     this.alerts = []; 
    } 

    factory(alertOptions): any { 
     var alert = { 
      type: alertOptions.type, 
      msg: this.sanitizer.sanitize(SecurityContext.HTML, alertOptions.msg), 
      id: alertOptions.alertId, 
      toast: alertOptions.toast 
     }; 
     this.alerts.push(alert); 
     return alert; 
    } 

    addAlert(alertOptions, extAlerts): any { 
     alertOptions.alertId = this.alertId++; 
     var alert = this.factory(alertOptions); 
     return alert; 
    } 

    isToast(): boolean { 
     return this.toast; 
    } 
} 

的服务，这里是该服务的提供商

import { Sanitizer } from '@angular/core'; 
import { AlertService } from './alert.service'; 

export function alertServiceProvider(toast?: boolean) { 
    // set below to true to make alerts look like toast 
    let isToast = toast ? toast : false; 
    return { 
     provide: AlertService, 
     useFactory: (sanitizer: Sanitizer) => new AlertService(sanitizer, isToast), 
     deps: [Sanitizer] 
    } 
} 

现在，您需要请在模块的提供程序声明中调用alertServiceProvider方法。

@NgModule({ 
    imports: [ 
     ... 
    ], 
    declarations: [ 
     ... 
    ], 
    providers: [ 
     ... 
     alertServiceProvider() 
    ], 
    exports: [ 
     ... 
    ] 
}) 
export class SharedCommonModule {} 

的代码是JHipster项目的一部分，你可以浏览实际模板here