Question

我有一个使用SOAP Web服务的Angular 2服务。为此，我使用具有回调函数的Javascript SOAP客户端。我知道服务方法的结果可能是Observable或Promise，但我不知道如何从回调函数返回服务。

这是我目前的代码：

import { Injectable } from '@angular/core';
declare var SOAPClient: any;//<-- The library I'm using, it doesn't have types

@Injectable()
export class SoapService {
  connection_url: Map<string,string>;
  constructor() {
   this.connection_url = new Map<string, string>();
   this.connection_url.set('Example', 'http://localhost:8080/MYAPP_EJB/ExampleSvc');
  }

  consume(service_name: string, method: string, parameters?: Map<string,any>){
   var that = this;
   return new Promise<any>(function(resolve){
      var params = new SOAPClientParameters();
      if(parameters !== null){
        for (let parameter of parameters.keys()){
          params.add(parameter,parameters.get(parameter));
        }
      }
      //Below is the line where I use the function with the callback function argument (function(j)), where j represents the response from the Web Service
      SOAPClient.invoke(that.connection_url.get(service_name), method,params,true,
      function(j){
              return new Promise<any>(function(resolve){
                console.log('Web Service Answer: ' + j.answer.entry.value);
                return j;
              });    
      }); //End of SOAPClient.invoke()
    }); //End of promise of consume()
  }//End of consume()
}//End of class

我可以做些什么来使用consume（）为组件提供Web服务响应？我是否需要对SOAPClient进行一些修改？

谢谢。

编辑：解决方案

我使用了Robin的答案并使用了bindCallback（与fromCallback相同的想法，请参阅bindCallback以供参考），使用SOAPClient.invoke作为该函数的参数。结果函数与原始函数相同，但不需要回调函数，而是返回Observable，我可以订阅，然后解析consume()的承诺。

新代码：

import { Injectable } from '@angular/core';
import * as Rx from "rxjs";
declare var SOAPClient: any;//<-- The library I'm using, it doesn't have types

@Injectable()
export class SoapService {
  connection_url: Map<string,string>;
  invokeSoapClient: any;
  constructor() {
   this.connection_url = new Map<string, string>();
   this.connection_url.set('Example', 'http://localhost:8080/MYAPP_EJB/ExampleSvc');
   this.invokeSoapClient = <any> Rx.Observable.bindCallback(SOAPClient.invoke);
  }

  consume(service_name: string, method: string, parameters?: Map<string,any>){
   var that = this;
   return new Promise<any>(function(resolve){
      var params = new SOAPClientParameters();
      if(parameters !== null){
        for (let parameter of parameters.keys()){
          params.add(parameter,parameters.get(parameter));
        }
      }
      var invokeObs = that.invokeSoapClient(that.conexion_url.get(service_name), method, params, true);
      invokeObs.subscribe(r => {resolve(r[0])}); //r is the answer from SOAPClient invoke, I just needed the response part.
    }); //End of promise of consume()
  }//End of consume()
}//End of class

Answer 1

最好的办法是从你的回调中创建一个observable。您可以轻松地从回调中创建可观察的内容。 check this out

Angular 2 Service - 使用具有回调函数作为参数的函数的Observable

编辑：解决方案

1 个答案: