FreeLists / dokuwiki / [dokuwiki] Re: AW: Re: Patch: Trigger IO_WIKIPAGE_WRITE on page delete

[Myron Turner <turnermm02@xxxxxxx>]

I'm sorry to jump in at this late date, but I it wasn't until I saw the 
patch that I actually looked at the code.  You've identified a problem 
that should be addressed but I'm not sure even if a patch is the way to 
solve it.
First, I'm wondering whether the patch would be backwardly 
compatible.    As you say, the event will now be triggered twice 
(actually 3 times--being triggered for writing to the attic).  It's true 
that users should have been checking for the empty data field to 
distinguish between a deletion and a write.  But the extra firing could 
cause some problems for legacy code.
I think that either a delete event should be triggered or, ideally, that 
the DokuWiki code should look at possibly correcting its current 
handling of  "empty" data.
My impression has been that the data field would be unreliable in any 
case, because a file is not considered empty by DokuWiki unless it has 
no data at all, which means that to delete a file, you must make sure it 
contains no characters at all.  My own event handlers, however, consider 
such files as empty and I delete them.   I haven't traced the sequencing 
of writes in DokuWiki and how they relate to deletions, but I'm not 
entirely sure where your patch would leave my code.
I think there is also an issue with regard to DokuWiki's code logic.   
Your patch places the triggering of this event in a code block which 
handles matters which have occurred after a write, after the file has 
been removed.  Ideally, the event should show an empty field because an 
empty file has just been written.   To be specific, the DokuWiki code reads:
      if ($wasRemoved){
      }
     else {
            io_writeWikiPage($file, $text, $id);
      }

The IO_WIKIPAGE_WRITE event is triggered out of the else block in 
io_writeWikiPage().  The patch places the new trigger in the $wasRemoved 
block.  As I said, I'm not sure about the DokuWiki the code sequence.  
But presumably, the empty file is being written in io_writeWikiPage().  
But for some reason the data field is not empty.  It may be that the 
file is previously designated as having been removed, and the code never 
gets to the else block and to io_writeWikiPage().
Again, sorry to come into this thread so late,

Myron



Gabriel Birke wrote:
> Hi,
>
> before I sent the patch, I asked on the list which version I should
> implement, but I got no feedback. I chose the IO_WIKIPAGE_WRITE solution to
> comply with the documentation on the events list (
> http://wiki.splitbrain.org/wiki:events_list#io_wikipage_write ). Triggering
> the event twice is standard behavior for updates (and with a little
> creativity, you can declare a deletion an "update" ;-) More important, the
> documentation states that on delete the variable $data[0][1] is empty. This
> empty data would not be sent without the patch.
>
> If one of the code maintainers sends me a mail, I will gladly provide a
> patch that provides a IO_WIKIPAGE_DELETE event (maybe even move the deletion
> code from common.php to io.php).
>
> Greetings,
>
> Gabriel
>
>
>   
> > -----Ursprüngliche Nachricht-----
> > Von: dokuwiki-bounce@xxxxxxxxxxxxx 
> > [mailto:dokuwiki-bounce@xxxxxxxxxxxxx] Im Auftrag von Guy Brand
> > Gesendet: Donnerstag, 20. Dezember 2007 21:58
> > An: dokuwiki@xxxxxxxxxxxxx
> > Betreff: [dokuwiki] Re: Patch: Trigger IO_WIKIPAGE_WRITE on 
> > page delete
> > On 19 December at 13:23, Gabriel Birke wrote:
> >
> >     
> > > After applying this patch, DokuWiki will fire two 
> > >       
> > IO_WIKIPAGE_WRITE events
> >     
> > > instead of one when a page is deleted. The first event has 
> > >       
> > no revision and
> >
> >   Hi Gabriel,
> >
> >   Naive question: why two times the same event and not a more specific
> >   DELETE event?
> >
> >
> > --
> >   bug
> > --
> > DokuWiki mailing list - more info at
> > http://wiki.splitbrain.org/wiki:mailinglist
> >
> >     
>   

--

_____________________
Myron Turner
http://www.room535.org
http://www.bstatzero.org
http://www.mturner.org/XML_PullParser/


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