XML Q&A with Darshan Singh

1. Create an instance of CInternetSession class. This begins an HTTP session.
   
   
2. Call CInternetSession::GetHttpConnection to get an instance of CHttpConnection. Pass the server and HTTP port to this method, and it establishes a connection to an HTTP server.
   
   
3. Open an HTTP request using CHttpConnection::OpenRequest. Pass the rest of the URL (except server name), the HTTP method (GET/POST/...) to this method, and it returns a CHttpFile object.
   
   
4. Optionally, call CHttpFile::AddRequestHeaders to supply any request headers.
   
   
5. Call CHttpFile::SendRequest to actually send the request and get the response back.
   
   
6. Use CHttpFile::QueryInfoStatusCode to find out if the HTTP request succeeded.
   
   
7. On success, use pHttpFile->Read to read the response bytes.
   
   
8. Finally, call CHttpFile::Close and CHttpConnection::Close.

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#include <afxinet.h>
...
...

static const TCHAR* g_lpszSOAPRequest =    
_T("<soap:Envelope "
    "xmlns:n='urn:xmethods-Temperature' "
    "xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/' "
    "xmlns:soapenc='http://schemas.xmlsoap.org/soap/encoding/' "
    "xmlns:xs='http://www.w3.org/2001/XMLSchema' "
    "xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'> "
    "<soap:Body soap:encodingStyle='http://schemas.xmlsoap.org/soap/encoding/'> "
    "  <n:getTemp> "
    "     <zipcode xsi:type='xs:string'>98007</zipcode> "
    "  </n:getTemp> "
   "</soap:Body> "
"</soap:Envelope>");

#define CHUNK_SIZE      2048
   
void CallWebService()
{
   try
   {
      //   1. Instantiate CInternetSession
      CInternetSession httpSession(_T("Sample Web Service Client"), 
                           1,
                           INTERNET_OPEN_TYPE_PRECONFIG,
                           NULL,
                           NULL,
                           INTERNET_FLAG_DONT_CACHE);
      
      //   2. Get CHttpConnection (Server URL and Port required)
      CHttpConnection* pHttpConnection = 
                              httpSession.GetHttpConnection(_T("services.xmethods.net"), 
                                 INTERNET_FLAG_NO_AUTO_REDIRECT,
                                 80, NULL, NULL);

      //   3. Open HTTP Request (pass method type [get/post/..] and URL path (except server name))
      CHttpFile* pHttpFile             = 
                              pHttpConnection->OpenRequest
                              (_T("POST"), 
                                 _T("soap/servlet/rpcrouter"), 
                                 NULL, 1, NULL, NULL, 
                                 INTERNET_FLAG_KEEP_CONNECTION |
                                 INTERNET_FLAG_EXISTING_CONNECT |
                                 INTERNET_FLAG_DONT_CACHE |
                                 INTERNET_FLAG_RELOAD);

      //   4. Add HTTP Request Headers
      CString strSOAPReq(g_lpszSOAPRequest);
      DWORD dwRewLen = strSOAPReq.GetLength();
      CString strHeaders;
      strHeaders.Format(_T("Content-Type: text/xml; charset=utf-8\nContent-Length:%d"), 
         dwRewLen);
      pHttpFile->AddRequestHeaders(strHeaders);

      
      //   5. Send the request
      pHttpFile->SendRequest(NULL, 0, (LPVOID)(LPCTSTR)strSOAPReq, dwRewLen);

      //   6. Check the return HTTP Status Code
      DWORD dwStatucCode = HTTP_STATUS_OK;

      pHttpFile->QueryInfoStatusCode(dwStatucCode);

      if(dwStatucCode == HTTP_STATUS_OK)
      {
         CString strResponse;
         TCHAR szBuf[CHUNK_SIZE] = {0};
         UINT nBytesRead;

         //   7. Read the response text
         do
         {
            nBytesRead = pHttpFile->Read((void*) szBuf, CHUNK_SIZE);
            strResponse += szBuf;
            if(nBytesRead < CHUNK_SIZE)
               break;
         }while(nBytesRead == CHUNK_SIZE);

         AfxMessageBox(strResponse);
         //TODO: Process the response
      }
      else
      {
         //TODO: Error handling
      }

      //   8. Close the stream/connection
      if(pHttpFile)
      {
         pHttpFile->Close();
         delete pHttpFile;
         pHttpFile = NULL;
      }

      if(pHttpConnection)
      {
         pHttpConnection->Close();
         delete pHttpConnection;
         pHttpConnection = NULL;
      }

   }
   catch(CInternetException* exp)
   {
      TCHAR lpszErrorMsg[MAX_PATH+2];
      exp->GetErrorMessage(lpszErrorMsg, MAX_PATH);
      AfxMessageBox(lpszErrorMsg);
   }
}
...
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#include "stdafx.h"
#include <atlbase.h>

#import <msxml4.dll> named_guids
using namespace MSXML2;

#define      MAX_XML_SIZE_KB      1

int main(int argc, char* argv[])
{

   CoInitialize(NULL);
   HRESULT hr = S_OK;
   {
      CComPtr<IXMLDOMDocument2> spXMLDOMDoc;
      hr = spXMLDOMDoc.CoCreateInstance(CLSID_DOMDocument40);

      spXMLDOMDoc->async = false;
      spXMLDOMDoc->resolveExternals = false;
      spXMLDOMDoc->validateOnParse = false;
      
      CComVariant cvMaxSize(MAX_XML_SIZE_KB);
      spXMLDOMDoc->setProperty(_T("MaxXMLSize"), cvMaxSize);


      if (spXMLDOMDoc->load(_T("c:\\1.xml")))
      {
         printf(_T("Load successful!"));
      }
      else
      {
         wprintf(spXMLDOMDoc->parseError->reason);
      }
   }
   
   CoUninitialize();

   return 0;
}

...
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      [WebMethod]
      public string SaveImage(string fileName, byte[] imageData)
      {
         try
         {
            string fileNameWithPath = Path.Combine(@"c:\temp\empImages", fileName);
            
            FileStream fileStream = new FileStream(fileNameWithPath, 
               FileMode.Create, FileAccess.Write);
               
            fileStream.Write(imageData, 0, imageData.Length);
            
            fileStream.Close();
         }
         catch(Exception exp)
         {
            return exp.ToString();
         }
         finally
         {
         }

         return "Success";
      }
...
...

    Dim objSOAPClient As New MSSOAPLib30.SoapClient30
    objSOAPClient.MSSoapInit "http://localhost/EmpImages/EmpImages.asmx?wsdl", "EmpImages"
    
    Dim backSlashPos As Integer
    Dim fileNameNoPath As String
    backSlashPos = InStrRev(txtFileName.Text, "\")
    If backSlashPos > 0 Then
        fileNameNoPath = Mid(txtFileName.Text, backSlashPos + 1)
    Else
        fileNameNoPath = txtFileName.Text
    End If
    
    Dim btArr() As Byte
    Open txtFileName.Text For Binary Access Read As #1
    ReDim btArr(LOF(1))
    Get #1, , btArr()
    Close #1
    
    MsgBox objSOAPClient.SaveImage(fileNameNoPath, btArr)

Dim soapReq As String
Dim objSOAPXMLDoc As New MSXML2.DOMDocument30
Dim objXMLHTTP As New MSXML2.XMLHTTP30

Dim btArr() As Byte

Dim backSlashPos As Integer
Dim fileNameNoPath As String

soapReq = "<?xml version='1.0' encoding='utf-8'?> " & _
   "<soap:Envelope xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' " & _
    " xmlns:xsd='http://www.w3.org/2001/XMLSchema' " & _
    " xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/'> " & _
   "  <soap:Body> " & _
   " <SaveImage xmlns='http://samples.perfectxml.com/BinaryData'> " & _
   "   <fileName></fileName> " & _
   "   <imageData></imageData> " & _
   " </SaveImage> " & _
   "  </soap:Body> " & _
   "</soap:Envelope> "

backSlashPos = InStrRev(txtFileName.Text, "\")
If backSlashPos > 0 Then
 fileNameNoPath = Mid(txtFileName.Text, backSlashPos + 1)
Else
 fileNameNoPath = txtFileName.Text
End If

objSOAPXMLDoc.loadXML soapReq

objSOAPXMLDoc.setProperty "SelectionNamespaces", _
 "xmlns:pxml='http://samples.perfectxml.com/BinaryData'"

objSOAPXMLDoc.selectSingleNode("//pxml:fileName").nodeTypedValue = _
 fileNameNoPath

objSOAPXMLDoc.selectSingleNode("//pxml:imageData").dataType = _
 "bin.base64"

Open txtFileName.Text For Binary Access Read As #1
ReDim btArr(LOF(1))
Get #1, , btArr()
Close #1

objSOAPXMLDoc.selectSingleNode("//pxml:imageData").nodeTypedValue = btArr
MsgBox objSOAPXMLDoc.xml

objXMLHTTP.open "POST", "http://localhost/EmpImages/EmpImages.asmx", False

objXMLHTTP.setRequestHeader "Content-Type", "text/xml; charset=utf-8"

objXMLHTTP.setRequestHeader "SOAPAction", _
     "http://samples.perfectxml.com/BinaryData/SaveImage"

objXMLHTTP.setRequestHeader "Content-Length", Len(objSOAPXMLDoc.xml)

objXMLHTTP.send objSOAPXMLDoc.xml

MsgBox objXMLHTTP.Status & ": " & objXMLHTTP.statusText
MsgBox objXMLHTTP.responseText

Set objXMLHTTP = Nothing
Set objSOAPXMLDoc = Nothing

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