Re: gnome bug 135093

On Fri, 2005-04-22 at 16:15 -0400, Thierry Moisan wrote:
> >[snip]
> >
> >  
> >
> >>I fixed the frontend except for one thing : in bug 135093 there's this line:
> >>    
> >>
> >
> >I'm looking forward to seeing this!
> >
> >  
> >
> Ok so I'm sending the patch for the frontend only. Tell me if there's 
> anything wrong.
Did you forget to attach the patch?

> 
> >>I've also looked for the cong_document_for_each_node function at this link :
> >>http://gtkdoc.conglomerate.org/0.7.16/CongDocument.html#cong-document-for-each-node 
> >>
> >>but the explanation of the funtion is a TODO. So could someone fill this 
> >>TODO or explain me how this funtion works and how to understand and use 
> >>this (or maybe both) :
> >>    
> >>
> >
> >I've committed this documentation of the function to CVS (it won't yet
> >appear on the website):
> >
> >/**
> > * cong_document_for_each_node:
> > * @doc: the document
> > * @callback: a callback to be invoked for every node in the document
> > * @callback_data: data for the callback
> > *
> > * Perform a depth-first traversal of the nodes in the DOM tree of this document, calling the supplied callback for each node,
> > * passing it the supplied data.  
> > * 
> > * If the callback returns TRUE, then traversal is halted: you can use this to test for the presence of a node satisfying some condition
> > * Otherwise, traversal continues.   If you wish to perform some operation on every node in the tree, your callback should always return FALSE.
> > * 
> > * Entity declarations are only visited once; it does not traverse below an entity reference, to avoid potential infinite loops.
> > *
> > * Returns:  TRUE if one of the callback calls returned TRUE (stopping the traversal prematurely); FALSE if the full traversal occurred
> > */
> >
> >Does this help?
> >
> >Dave
> >
> >
> >  
> >
> Yeah thanks this helps a lot. But I have some questions left :
> 1) what is a node?
CongNodePtr/xmlNodePtr are used interchangably; it's a pointer to a
libxml2 representation of a DOM node.  So every fragment of text in the
document appears as a DOM node of type TEXT (have a look in
src/cong-node.h)

> 2) by  a traversal do you mean that this goes trough all the nodes of 
> the DOM tree?
Yes.

> 3) Could the callback be like number = number+1 and number would be the 
Yes, and pass a pointer to an integer as the data.  Or you could have a
struct containing the integer, and pass a pointer to that (in case you
want to count more than one thing).

> callback_data? If not please explain me what's a callback and what would 
> be callback_data.
Have a look here:
http://www.indopedia.org/Callback_(computer_science).html