Re: [xml] document() and import() handlers

[Matt Sergeant <matt sergeant org>]

On Sun, 11 Mar 2001, Matt Sergeant wrote:

> On Sun, 11 Mar 2001, Daniel Veillard wrote:
>
> > On Sun, Mar 11, 2001 at 12:18:02PM +0000, Matt Sergeant wrote:
> > > On Sun, 11 Mar 2001, Daniel Veillard wrote:
> > >
> > > >    You can register new handlers, based on the URI string they can intercept
> > > > the default I/O routines of libxml:
> > > >     use xmlRegisterInputCallbacks ()
> > > >     http://xmlsoft.org/html/libxml-xmlio.html#XMLREGISTERINPUTCALLBACKS
> > > >     again it works with a set of 4 callbacks:
> > > >     match()
> > > >     open()
> > > >     read()
> > > >     close()
> > >
> > > These methods need to send some sort of user data, otherwise I can't do
> > > per-instance callbacks, and I have no way to do matches in Perl-space.
> >
> >   match() should not need it
>
> It doesn't need it if implementing in C space, but Perl is a dynamic
> language, so I want to be able to set the match conditions in Perl space.
> Without any sort of context pointer I can't do that (because I have no way
> of knowing what Perl sub to call from within C-space).
>
> >   open() returns the user data associated
> >   which is passwd as first arg of
> >   read() and close()
>
> Even these methods require a context object, for exactly the same reason
> as match() - I need a Perl SV * to be able to know what Perl method to
> call. Otherwise I have to hard code the method and package name, which is
> not nice.

Just FYI, I got around this limitation by using a global variable. I
assume that this will be OK with libxml because of my calls to
xmlInitParser (which I'm guessing is some sort of mutex mechanism, freed
by the parse finishing?).

-- 
<Matt/>

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