Re: [xml] request

[Daniel Veillard <veillard redhat com>]

On Wed, Nov 28, 2001 at 09:48:26AM +0100, robert wrote:
> Daniel,
>
> With xmlRegisterInputCallbacks() in xmlIO.c, it's possible to overload
> the file-I/O routines. I use this function to implement my own I/O stuff,
> because of the environment I run libxml in (multi-threaded, and files are
> mostly only accessibly through special routines).

  Okay, sounds perfect.

> However, it doesn't seem to be possible to remove the default callbacks,
> also in xmlIO.c, altogether: when I call xmlCleanupInputCallbacks(),
> the xmlInputCallbackInitialized variable is set to false, and at
> some points the value of this variable is checked. If false, the
> default callbacks are put in place again (this happens, for example, in
> xmlParserInputBufferCreateFilename and xmlParserInputBufferCreateFile).

  Hum, actually the xmlCleanupInputCallbacks() and 
xmlCleanupOutputCallbacks() functions were designed specifically for the
use you suggest, they are not called by libxml itself it a purely user
convenience function.
  The fact that it resets xmlInputCallbackInitialized is actually a bug
since it breaks the expected use of the function. As the doc says it
should clear the table not make it invalid.

> How do you think about creating a new function which can be used to set
> the xmlInputCallbackInitialized-variable? Because the variable is static
> (which is a good thing), I cannot tamper with it from within my own code. A
> function which can be used to set it would be of great help to me.

  The right thing is to remove 
   xmlInputCallbackInitialized = 0;
and
   xmlOutputCallbackInitialized = 0;

from those two functions. I tested and commited this,

  thanks again, seems not that people used that code before :-\

Daniel

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