FrapMenu menu/item ordering

[Stephan Arts]

On 2/22/07, Jannis Pohlmann <jannis at xfce.org> wrote:
> On Thu, 22 Feb 2007 12:42:38 -0500, Erik Harrison wrote:
>
> > On 2/22/07, Brian J. Tarricone <bjt23 at cornell.edu> wrote:
> > > -----BEGIN PGP SIGNED MESSAGE-----
> > > Hash: SHA1
> > >
> > > On Thu, 22 Feb 2007 09:05:16 +0100 Stephan Arts wrote:
> > >
> > > >On 2/21/07, Brian J. Tarricone <bjt23 at cornell.edu> wrote:
> > > >> -----BEGIN PGP SIGNED MESSAGE-----
> > > >> Hash: SHA1
> > > >>
> > > >> On Wed, 21 Feb 2007 20:42:36 +0100 Stefan Stuhr wrote:
> > > >>
> > > >> > ons, 21 02 2007 kl. 20:19 +0100, skrev Jannis Pohlmann:
> > > >> > > They're unsorted as the order is unimportant for internal
> > > >> > > use. Comparing them by names is really easy with the help of
> > > >> > > a GCompareFunc as you can see above.
> > > >> >
> > > >> > I will admit that I don't know the fd.org menu standard, but
> > > >> > if the implementation in GNOME follows the standard (I do
> > > >> > believe that it does), then the order does matter - and not
> > > >> > necessary a sorted order.
> > > >>
> > > >> Agreed.  If FrapMenu can't preserve the order from the .menu
> > > >> file, that's a *huge* limitation.  How will people make menus
> > > >> with arbitrarily-ordered items?
> > > >
> > > >Sorry to disappoint you there, but the XML standard does not force
> > > >siblings to be entered in a specific order. As such, there is no
> > > >XML parser which will guarantee you that xml-nodes are returned in
> > > >the order they come up in the file. And they do not have too, it
> > > >is not part of XML-spec itself.
> > > >
> > > >As a consequence of this, it is impossible for FrapMenu (or any
> > > >other application which uses XML) to preserve the order since it
> > > >is not even certain that the order in which the nodes are
> > > >presented to him is the order in which they where inside the file.
> > > >
> > > >On a side-node, usually it does work this way, but we cannot rely
> > > >on this.
> > >
> > > Er, are you aware of any XML parsers that *don't* return them in
> > > order?  libxml2 and the gmarkup parser both do, last I checked, and
> > > I can't see why a parser wouldn't do this.
> > >
> > > Regardless: if it is not possible to specify a strict ordering of
> > > the menu -- whether a limitation of XML itself, or in the menu spec
> > > -- I consider the spec broken.  The menu spec's <Layout> element
> > > (when Jannis implements support for it) should work fine, though it
> > > *does* functionally depend on the XML parser returning elements in
> > > order.
> > >
> > > If what you say is true, I can think of several other popular
> > > applications that use XML for ordered lists; I'd be very surprised
> > > to find out that that method ever breaks.
> >
> > Like XHTML? If the nodes were unordered. Oh man. That would be awesome
>
> Exactly what I was thinking about as well. Even from the technical point
> of view this makes sense. I mean, IO methods return chracters in order,
> so a parser usually would read element by element from the top to the
> bottom of the file. It would be strange if during that elements were
> randomly inserted into the XML tree in memory.
>
> Don't worry about XML element order - you'll get the layout
> capabilities you need anyway, sooner or later.

I wont ;)

Back when i used libxml2, i remember one parser, (i thought it was
SAX) which explicitly stated i should not rely on xml-nodes being
interpreted in a specific order.
However, it could be i misunderstood the docs and they mentioned a bug.

Stephan