httpexampleengine.cpp

HTTP引擎

/**
*
* @brief Definition of CHTTPExampleEngine
*
* Copyright (c) EMCC Software Ltd 2003
* @version 1.0
*/

// INCLUDE FILES

// Class include
#include "HTTPExampleEngine.h"

// System includes
#include <chttpformencoder.h>        // CHTTPFormEncoder
#include <httpstringconstants.h>    // HTTP string table
#include <rhttpheaders.h>            // RHTTPHeaders

// User includes
#include "HTTPExample.hrh"            // EMaxNameLength

// CONSTANTS
// HTTP header values
_LIT8(KUserAgent, "HTTPExample (1.0)");    // Name of this client app
_LIT8(KAccept, "text/*");                // Accept any (but only) text content
_LIT8(KPostParamName, "NAME");            // Name of the parameter sent in a POST request
_LIT8(KPostContentType, "text/plain");    // Content type sent in a POST request

// URL for POST request.
//_LIT8(KPostUri, "http://cgi.www.emccsoft.com/cgi-bin/www.emccsoft.com/post.pl");
_LIT8(KPostUri, "http://www.magpiemobile.com/cgi-bin/book_post.cgi");


// ================= MEMBER FUNCTIONS =======================

/**
* 2-phase constructor
*
* @param aObserver An observer of this engine (e.g. the UI)
*/
CHTTPExampleEngine* CHTTPExampleEngine::NewL(MHTTPExampleEngineObserver& aObserver)
{
    CHTTPExampleEngine* self = new (ELeave) CHTTPExampleEngine(aObserver);
    CleanupStack::PushL(self);
    self->ConstructL();
    CleanupStack::Pop(self);
    return self;
}

/**
* C++ constructor
*
* @param aObserver An observer of this engine (e.g. the UI)
*/
CHTTPExampleEngine::CHTTPExampleEngine(MHTTPExampleEngineObserver& aObserver)
: iObserver(aObserver)
{
}

/**
* 2nd-phase constructor
*/
void CHTTPExampleEngine::ConstructL()
{
    // Open the RHTTPSession
    iSession.OpenL();

    // Construct the form encoder
    iFormEncoder = CHTTPFormEncoder::NewL();
}

/**
* C++ destructor
*/
CHTTPExampleEngine::~CHTTPExampleEngine()
{
    // Close session
    iSession.Close();    // Will also close any open transactions
    delete iResponseBuffer;
    delete iFormEncoder;
    delete iUri;
}

/**
* Override of pure virtual method in MHTTPTransactionCallback.
* Called to report progress by a currently outstanding transaction.
*
* @param aTransaction The transaction reporting progress
* @param aEvent The event being notified
*/
void CHTTPExampleEngine::MHFRunL(RHTTPTransaction aTransaction, const THTTPEvent& aEvent)
{
    switch (aEvent.iStatus)
    {
        case THTTPEvent::EGotResponseHeaders:
        {
            // HTTP response headers have been received.
            // Pass status information to observer.
            RHTTPResponse resp = aTransaction.Response();

            // Get status code
            TInt statusCode = resp.StatusCode();

            // Get status text
            RStringF statusStr = resp.StatusText();
            HBufC* statusBuf = HBufC::NewLC(statusStr.DesC().Length());
            statusBuf->Des().Copy(statusStr.DesC());

            // Inform observer
            iObserver.ResponseStatusL(statusCode, *statusBuf);

            CleanupStack::PopAndDestroy(statusBuf);
        }
            break;


        case THTTPEvent::EGotResponseBodyData:
        {
            // Get text of response body
            MHTTPDataSupplier* dataSupplier = aTransaction.Response().Body();
            TPtrC8 ptr;
            dataSupplier->GetNextDataPart(ptr);

            // Convert to 16-bit descriptor
            HBufC* buf = HBufC::NewLC(ptr.Length());
            buf->Des().Copy(ptr);

            // Append to iResponseBuffer
            if (!iResponseBuffer)
            {
                iResponseBuffer = buf->AllocL();
            }
            else
            {
                iResponseBuffer = iResponseBuffer->ReAllocL(iResponseBuffer->Length() + buf->Length());
                iResponseBuffer->Des().Append(*buf);
            }

            // Release buf
            CleanupStack::PopAndDestroy(buf);

            // Release the body data
            dataSupplier->ReleaseData();
        }
            break;

        case THTTPEvent::EResponseComplete:
        {
            // Pass the response buffer by reference to the observer
            iObserver.ResponseReceivedL(*iResponseBuffer);
        }
            break;
    }
}

/**
*/
TInt CHTTPExampleEngine::MHFRunError(TInt aError, RHTTPTransaction /*aTransaction*/, const THTTPEvent& /*aEvent*/)
{
    return aError;
}


/**
* Initiate a GET request
*
* @param aUri The URI to get
*/
void CHTTPExampleEngine::GetRequestL(const TDesC& aUri)
{
    // Parse the URI
    ParseUriL(aUri);

    // Create the transaction
    iTransaction = iSession.OpenTransactionL(iUriParser, *this,
        iSession.StringPool().StringF(HTTP::EGET, RHTTPSession::GetTable()));

    // Set transaction headers
    RHTTPHeaders headers = iTransaction.Request().GetHeaderCollection();
    AddHeaderL(headers, HTTP::EUserAgent, KUserAgent);
    AddHeaderL(headers, HTTP::EAccept, KAccept);

    // Submit the request
    iTransaction.SubmitL();
}


/**
* Initiate a POST request
*
* @param aName The user's name
*/
void CHTTPExampleEngine::PostRequestL(const TDesC& aName)
{
    // Build form encoder
    // Start by removing any previous content
    delete iFormEncoder;
    iFormEncoder = NULL;
    iFormEncoder = CHTTPFormEncoder::NewL();
    TBuf8<EMaxNameLength> buf8;
    buf8.Copy(aName);
    iFormEncoder->AddFieldL(KPostParamName, buf8);

    // Create transaction
    iUriParser.Parse(KPostUri);
    iTransaction = iSession.OpenTransactionL(iUriParser, *this,
        iSession.StringPool().StringF(HTTP::EPOST, RHTTPSession::GetTable()));

    // Set transaction headers
    RHTTPHeaders headers = iTransaction.Request().GetHeaderCollection();
    AddHeaderL(headers, HTTP::EUserAgent, KUserAgent);
    AddHeaderL(headers, HTTP::EAccept, KAccept);
    AddHeaderL(headers, HTTP::EContentType, KPostContentType);

    // Set the form encoder as the data supplier
    iTransaction.Request().SetBody(*iFormEncoder);

    // Submit the request
    iTransaction.SubmitL();
}


//
// Utility methods
//

/**
* Parse a URI
*
* @param aUri The URI to be parsed
*/
void CHTTPExampleEngine::ParseUriL(const TDesC& aUri)
{
    // Convert the URI to an 8-bit descriptor
    // then set iUriParser to point at it
    delete iUri;
    iUri = NULL;
    iUri = HBufC8::NewL(aUri.Length());
    iUri->Des().Copy(aUri);
    User::LeaveIfError(iUriParser.Parse(*iUri));
}


/**
* Add a header to a header set
*
* @param aHeaders The header set to be modified
* @param aHeaderField The name of the header to be added
* @param aHeaderValue The value for the header to be added
*/
void CHTTPExampleEngine::AddHeaderL(RHTTPHeaders aHeaders, TInt aHeaderField, const TDesC8& aHeaderValue)
{
    RStringPool stringPool = iSession.StringPool();
    RStringF valStr = stringPool.OpenFStringL(aHeaderValue);
    THTTPHdrVal headerVal(valStr);
    aHeaders.SetFieldL(stringPool.StringF(aHeaderField, RHTTPSession::GetTable()), headerVal);
    valStr.Close();
}


/**
* Cancel any outstanding transaction
*/
void CHTTPExampleEngine::Cancel()
{
    iTransaction.Cancel();
}