Hi All, First, I have read, reread, and re-re-re-read the page at: http://gambasdoc.org/help/howto/extern?v3 and I still seem to be missing something...
I am trying to use TidyLib in Gambas 3. I have been able to create documents and buffers but seem to be unable to use the buffers I create with Tidy. Tidy uses the C functions alloc and realloc internally for memory allocation. It stores information in structures of various types and returns a pointer to the structures it creates (often these structures are not much more than grouped pointers to other objects). In theory, I should be able to accept a pointer to a structure and then pass that pointer to other tidy functions just as i would in C. My file is quit long so I am only posting the relevant code here. If I define a pointer to a buffer and then pass the pointer to tidyInitBuf(myptr) I get a success return code and printing the pointer value reveals the pointer is no longer null. However, any attempt to pass the pointer back to one of tidy's other functions results in a SEG Fault error when the buffer is used. What am I missing here? '====================================== ' Gambas class file '' @Class: HTMLTidy '' @File: HTMLTidy.class '' @Ver: 0.1.0 '' @Date: '' @ Desc: A wrapper for HtmlTidy's libtidy c library '' '' @Note: Not yet ready for prime time... '===================================== Export Library "libtidy" ' Declare external library ' --- Tidy Types Defines --- ' Some of these Defs are just for reference and may not be used ' in the application ' -- Tidy Buffers Public Struct TidyBufferType allocator As Pointer ' Memory allocator bp As Pointer ' Pointer To bytes size As Integer ' #bytes currently In use allocated As Integer ' #bytes allocated tNext As Integer ' Offset Of current Input position End Struct ' -- Tidy Nodes Public Struct NodeType nparent As Pointer ' tree structure nprev As Pointer nnext As Pointer ncontent As Pointer nlast As Pointer attributes As Pointer ' pointer to attribute value structure nwas As Pointer ' Old tag before it was changed ntag As Pointer ' tag's dictionary definition element As Pointer ' name (NULL for text nodes) nstart As Integer ' start of span into text array nend As Integer ' end of span onto text array ntype As Integer ' TextNode, StartTag, EndTag, etc... nline As Integer ' Current line of document ncolumn As Integer ' current column of document nclosed As Boolean ' true if closed by explicit end tag nimplicit As Boolean ' true if inferred nlinebreak As Boolean ' true if followed by a line break otext As String ' Used on with TIDY_STORE_ORIGINAL_TEXT End Struct ' --- Tidy Memory and Structure Allocation methods --- ' TidyDoc tidyCreate(void) Extern tidyCreate() As Pointer ' Initialize Buffer Extern tidyBufInit(buf As Pointer) ' Free Ouptut and error buffers Extern tidyBufFree(pOutput As Pointer) ' Capture diagnostics in error buffer ' tidySetErrorBuffer( tdoc, &errbuf ); Capture diagnostics Extern tidySetErrorBuffer(tdoc As Pointer, errbuf As Pointer) As Integer '-- Tidy Set Option methods --- ' Set Boolean Option value ' tidyOptSetBool( tdoc, TidyXhtmlOut, yes ); // Convert to XHTML Extern tidyOptSetBool(tdoc As Pointer, Option As Pointer, value As Boolean) As Boolean '--- Tidy Document methods --- ' Parse the Input ' tidyParseString( tdoc, input ); Parse the input Extern tidyParseString(tdoc As Pointer, sInput As Pointer) As Integer ' Tidy it up! Extern tidyCleanAndRepair(tdoc As Pointer) As Integer ' Get Error Codes, if any Extern tidyRunDiagnostics(tdoc As Pointer) As Integer ' Pretty Print Extern tidySaveBuffer(tdoc As Pointer, pOutput As Pointer) As Integer Public pTidyDoc As Pointer Public pErrBuf As Pointer pTidyDoc = tidyCreate() pErrBuff = tidyInitBuf(VarPtr(pErrBuf)) ' tidy should be allocating memory and returning a pointer to a buffer structure. In fact tidy does return a success code. ' However the following line results in a Severe Error code being returned by tidy. tidySetErrorBuf(pTidyDoc, pErrBuff) 'After this call all further calls to any tidy function that makes use of the error buffer results in a segment fault. ' If I allow tidy to create and manage it's own error buffer( which it does using the same functions I called manually, then everything runs smoothly. ' So what have I missed in the use of the pointer? Lastly, in order to read data from a structure that I have obtained a pointer to from a tidy function, do I need to use READ? For example, the tidyGetRoot() method returns a pointer to a TidyNode structure that tidy has created in memory. How can I best access the various elements in the node structure and make them avaliable as a Gambas 3 variable. Perhaps members of a Gambas class or structure. Sorry for the lengthy post and thanks to anyone who can provide a little insight for me... -- If you ask me if it can be done. The answer is YES, it can always be done. The correct questions however are... What will it cost, and how long will it take? ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ Gambas-user mailing list Gambas-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gambas-user
