IHttpModuleFactory::GetHttpModule Method
Creates an instance of a CHttpModule class.
An HRESULT. Possible values include, but are not limited to, those in the following table.
Value | Description |
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S_OK | Indicates that the operation was successful. |
 Note: |
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Because your module factory is required to provide a GetHttpModule method, you can provide any status code for the return value as appropriate for your application. At the very least, your GetHttpModule method should return S_OK to indicate a successful completion. |
An IHttpModuleFactory interface must provide a GetHttpModule method that creates an instance of your CHttpModule class. When IIS calls your module's exported RegisterModule function, IIS will use module factory's GetHttpModule method to create an instance of your CHttpModule class.
The following code example demonstrates how to create a simple "Hello World" HTTP module. The module defines an exported RegisterModule function that passes an instance of an IHttpModuleFactory interface to the IHttpModuleRegistrationInfo::SetRequestNotifications method and registers for the RQ_BEGIN_REQUEST notification. IIS uses the GetHttpModule method to create an instance of a CHttpModule class and returns a success status. IIS also uses the Terminate method of the IHttpModuleFactory interface to remove the factory from memory.
When a RQ_BEGIN_REQUEST notification is triggered, IIS calls the module's CHttpModule::OnBeginRequest method to process the current request. OnBeginRequest clears the response buffer and modifies the MIME type for the response. The method then creates a data chunk that contains a "Hello World" string and returns the string to a Web client. Finally, the module returns a status indicator that notifies IIS that all notifications are finished and then exits.
#define _WINSOCKAPI_ #include <windows.h> #include <sal.h> #include <httpserv.h> // Create the module class. class CHelloWorld : public CHttpModule { public: REQUEST_NOTIFICATION_STATUS OnBeginRequest( IN IHttpContext * pHttpContext, IN IHttpEventProvider * pProvider ) { UNREFERENCED_PARAMETER( pProvider ); // Create an HRESULT to receive return values from methods. HRESULT hr; // Retrieve a pointer to the response. IHttpResponse * pHttpResponse = pHttpContext->GetResponse(); // Test for an error. if (pHttpResponse != NULL) { // Clear the existing response. pHttpResponse->Clear(); // Set the MIME type to plain text. pHttpResponse->SetHeader( HttpHeaderContentType,"text/plain", (USHORT)strlen("text/plain"),TRUE); // Create a string with the response. PCSTR pszBuffer = "Hello World!"; // Create a data chunk. HTTP_DATA_CHUNK dataChunk; // Set the chunk to a chunk in memory. dataChunk.DataChunkType = HttpDataChunkFromMemory; // Buffer for bytes written of data chunk. DWORD cbSent; // Set the chunk to the buffer. dataChunk.FromMemory.pBuffer = (PVOID) pszBuffer; // Set the chunk size to the buffer size. dataChunk.FromMemory.BufferLength = (USHORT) strlen(pszBuffer); // Insert the data chunk into the response. hr = pHttpResponse->WriteEntityChunks( &dataChunk,1,FALSE,TRUE,&cbSent); // Test for an error. if (FAILED(hr)) { // Set the HTTP status. pHttpResponse->SetStatus(500,"Server Error",0,hr); } // End additional processing. return RQ_NOTIFICATION_FINISH_REQUEST; } // Return processing to the pipeline. return RQ_NOTIFICATION_CONTINUE; } }; // Create the module's class factory. class CHelloWorldFactory : public IHttpModuleFactory { public: HRESULT GetHttpModule( OUT CHttpModule ** ppModule, IN IModuleAllocator * pAllocator ) { UNREFERENCED_PARAMETER( pAllocator ); // Create a new instance. CHelloWorld * pModule = new CHelloWorld; // Test for an error. if (!pModule) { // Return an error if the factory cannot create the instance. return HRESULT_FROM_WIN32( ERROR_NOT_ENOUGH_MEMORY ); } else { // Return a pointer to the module. *ppModule = pModule; pModule = NULL; // Return a success status. return S_OK; } } void Terminate() { // Remove the class from memory. delete this; } }; // Create the module's exported registration function. HRESULT __stdcall RegisterModule( DWORD dwServerVersion, IHttpModuleRegistrationInfo * pModuleInfo, IHttpServer * pGlobalInfo ) { UNREFERENCED_PARAMETER( dwServerVersion ); UNREFERENCED_PARAMETER( pGlobalInfo ); // Set the request notifications and exit. return pModuleInfo->SetRequestNotifications( new CHelloWorldFactory, RQ_BEGIN_REQUEST, 0 ); }
Your module must export the RegisterModule function. You can export this function by creating a module definition (.def) file for your project, or you can compile the module by using the /EXPORT:RegisterModule switch. For more information, see Walkthrough: Creating a Request-Level HTTP Module By Using Native Code.
You can optionally compile the code by using the __stdcall (/Gz) calling convention instead of explicitly declaring the calling convention for each function.
Type | Description |
|---|---|
Client |
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Server |
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Product | IIS 7.0, IIS 7.5, IIS Express 7.5, IIS 8.0 |
Header | Httpserv.h |
