"Re:[xslt] debugger callbacks"

[Kasimier Buchcik <kbuchcik 4commerce de>]

Hi,

Keith Isdale wrote:
> Have you set xslDebugStatus to something other than XSLT_DEBUG_NONE, see 
> <libxslt/xsltutils.h>.  You may find you can get the information that you 
> want using xsldbg :-). 

No I did not set xslDebugStatus. Does this variable need to be set to 
something? I learned that is it declared in "deprecated.c", but I cannot 
set any variables, since I'm using Delphi 6 with the Pascal bindings to 
access the libxslt library.

Could you implement a function that sets this variable?

> Known cavates for the debugger callback functions are:
> 	o Be careful if you are modifing the data XSLT engine data structures  during 
> a debugging step as you could put the tranformation engine into a bad state 
> and give misleading resuilts.  
> 	o Be aware that the callbacks may not be in the same order as you would read 
> the text source for the XSLT script.  
> 	o The XSLT pre-processing step will remove certain redundant  nodes, such as 
> comment nodes, from the XSLT script before main work of  XSLT transformation 
> is done. 
> 	o Line number information may or may not be available for any given XmlNode 
> due to optimizations done during the pre-processing step
> 	o Whilst the xslAddCall and xslDropCall are always done in pairs the call 
> stack depth can get over stated.  This is because transformation of some XSLT 
> commands, for example xsl:for-each, increase the call stack depth otherwise 
> there would be no way to know how to "break  out"  of the for loop. 
> 
> 
> ------
> 
> Daniel: Maybe these cavates could be added to the libxslt FAQ. I had trouble 
> when I did  a search on xslDebugStatus in the XSLT API.  And I was suprised 
> to get a "Error 404"  when pointing my browser at 
> 	http://xmlsoft.org/XSLT/XSLT/html/libxslt-transform.html#XSLHANDLEDEBUGGER
> as suggested by the "xslHandleDebugger" link resulting from pointing my 
> browser at 
> http://xmlsoft.org/XSLT/search.php?query=xslDebugStatus+&submit=Search+...
> (URL tested on Mozilla and Konqueror). 
> 
> 
> Kasimier wrote;
> 
>>I tried to use xsltSetDebuggerCallbacks to get some callbacks during the=20
>>transformation, but the registered functions are not called. Since a=20
>>call of xslAddCall, fires the registered callback, I assume that=20
>>xsltDebuggerCurrentCallbacks is correctly initialized.
>>I guess libxslt (version see below) was compiled with WITH_DEBUGGER.

Thanks for the hints Keith,

Kasimier Buchcik