CHttpModule::OnMapPath Method

Article
05/24/2022

Represents the method that will handle a MapPath event, which occurs when an operation requests the physical path to be mapped for the current request.

Syntax

virtual REQUEST_NOTIFICATION_STATUS OnMapPath(  
   IN IHttpContext* pHttpContext,  
   IN IMapPathProvider* pProvider  
);

Parameters

pHttpContext
[IN] A pointer to an IHttpContext interface.

pProvider
[IN] A pointer to an IMapPathProvider interface.

Return Value

A REQUEST_NOTIFICATION_STATUS value.

Remarks

When a request-level module is registered for the RQ_MAP_PATH notification, IIS will call the module's OnMapPath method when an operation requests the physical path to be mapped for the current request.

Note

Request-level modules can register for the MapPath event notification by registering for RQ_MAP_PATH in the module's RegisterModule function.

Example

The following code example demonstrates how to create a request-level HTTP module that registers for the RQ_MAP_PATH event notifications. When an operation requests the physical path to be mapped for the current request, IIS will call the example module's OnMapPath method.

//  Insert data from ostringstream into the response
//  On error, Provider error status set here
//  ostringstream  buffer cleared for next call 

HRESULT  WECbyRefChunk( std::ostringstream  &os, IHttpContext *pHttpContext, 
                       IHttpEventProvider *pProvider, LONG InsertPosition= -1)
{
    HRESULT hr = S_OK;

    IHttpTraceContext * pTraceContext = pHttpContext->GetTraceContext();

    hr = pTraceContext->QuickTrace(L"WECbyRefChunk",L"data 2",E_FAIL,6);
    if (FAILED(hr)){
        LOG_ERR_HR(hr,"QuickTrace");
        return hr;
    }
    // create convenience string from ostringstream  
    std::string str(os.str());

    HTTP_DATA_CHUNK dc;
    dc.DataChunkType = HttpDataChunkFromMemory;
    dc.FromMemory.BufferLength = static_cast<DWORD>(str.size());
    dc.FromMemory.pBuffer = pHttpContext->AllocateRequestMemory( 
        static_cast<DWORD>( str.size()+1) );

    if(!dc.FromMemory.pBuffer){
        hr = HRESULT_FROM_WIN32(ERROR_NOT_ENOUGH_MEMORY);
        LOG_ERR_HR(hr,"AllocateRequestMemory");
        pProvider->SetErrorStatus(hr);
        return hr;
    }

    //  use char pointer p for convenience
    char *p = static_cast<char *>(dc.FromMemory.pBuffer);
    strcpy_s(p, str.size()+1, str.c_str());

    hr = pHttpContext->GetResponse()->WriteEntityChunkByReference( 
        &dc, InsertPosition );

    if (FAILED(hr)){
        LOG_ERR_HR(hr,"AllocateRequestMemory");
        pProvider->SetErrorStatus( hr );
    }

    os.str("");                // clear the ostringstream for next call

    return hr;
}

Requirements

Type	Description
Client	- IIS 7.0 on Windows Vista - IIS 7.5 on Windows 7 - IIS 8.0 on Windows 8 - IIS 10.0 on Windows 10
Server	- IIS 7.0 on Windows Server 2008 - IIS 7.5 on Windows Server 2008 R2 - IIS 8.0 on Windows Server 2012 - IIS 8.5 on Windows Server 2012 R2 - IIS 10.0 on Windows Server 2016
Product	- IIS 7.0, IIS 7.5, IIS 8.0, IIS 8.5, IIS 10.0 - IIS Express 7.5, IIS Express 8.0, IIS Express 10.0
Header	Httpserv.h

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