Re: Q:Dia XML-Language; Meaning of attributes for Dia UML objects

[Lars Clausen <lrclause cs uiuc edu>]

On Fri, 13 Sep 2002, Johannes Eble wrote:
> Hello,
> 
> Is there any documentation of the XML attributes for the UML objects? For
> example, a simple Class object does contain (among others) the following
> tags:
> 
>     <object type="UML - Class" version="0" id="O0">
>       <attribute name="obj_pos">
>         <point val="3.5,5.5"/>
>       </attribute>
>       <attribute name="obj_bb">
>         <rectangle val="3.5,5.5;20.4624,8.95"/>
>       </attribute>
>       <attribute name="elem_corner">
>         <point val="3.5,5.5"/>
>       </attribute>
>       <attribute name="elem_width">
>         <real val="16.8624"/>
>       </attribute>
>       <attribute name="elem_height">
>         <real val="3.4"/>
>       </attribute>
> 
> I do not understand "obj_bb". Also, there seems to be redundant
> information, i.e. "elem_width" should be calculated 20.4624-3.5 and the
> list goes on. The Generalization object is even more difficult for me.

obj_bb is the bounding box, which, like the width, is calculated from the
other values (but not in a manner easily derived from the info in the XML
file).  I wouldn't mind getting that extra info out of the XML files, it's
dead weight that has been causing trouble before.  

Hmmm... yeah, it's in need of some docs, indeed.  I've set up an area on
our TWiki for that (http://faemalia.org/wiki/view/Technical/DiaEditor).
Add questions there, and we shall provide the answers.

> I have had a look on the code for Autodia (the template and the handler)
> which gives me some ideas about the meaning of the attributes, but this
> is cumbersome. Also, Dia just crashes if there is something wrong or
> inconsistent in the XML file.

Yeah, haven't gotten around to do powerful error checking yet.

> Isn't there any more complete description available? I am only interested
> in the UML objects.

All we have is the DTDs in the doc directory.

-Lars

-- 
Lars Clausen (http://shasta.cs.uiuc.edu/~lrclause)| Hårdgrim of Numenor
"I do not agree with a word that you say, but I   |----------------------------
will defend to the death your right to say it."   | Where are we going, and
    --Evelyn Beatrice Hall paraphrasing Voltaire  | what's with the handbasket?