[Chameleon] Context file and Tree Legend

[Kralidis,Tom [Burlington]]

Hi,

You may be able to achieve this through the XML Theme files?  This groups
layers together in this manner.  We had this requirement in earlier
projects.

Recent versions of Chameleon support non-context imports.  However, keep in
mind by that supporting context documents, you can create and use, share
context documents from and to any application.

..Tom

=========================
Tom Kralidis
Systems Scientist
Environment Canada
Tel: +01-905-336-4409
http://www.ec.gc.ca/cise/

========================= 


-----Original Message-----
From: Dave Astolfo [mailto:dastolfo1@cogeco.ca] 
Sent: Tuesday, January 27, 2004 10:40 AM
To: Chameleon@lists.maptools.org
Subject: [Chameleon] Context file and Tree Legend


Hi All, 
I am somewhat new to Chameleon / MapServer. I have been challenged with
having to create a new Legend Widget.  Here is what I am trying to do:


I am  trying to create a legend that uses a tree-like structure (multi
level).  
LEGEND 
Layer List 
+  Category 1 
-------Category 1.1 
-------Category 1.2 
+  Category 2 
-------Category 2.1 
-------Category 2.2 
... etc.... 


The challenge is that the information needed to create the legend would be
more than the Context file contains.  For example,  in order to know where
to place a Layer name in the tree,
 the context file would require additional info such as PARENT_ID.  I was
able to get this working in the GMAP demo by some JavaScript I found. The
challenge here is that GMAP was written 
In PHP and JavaScript while we need to get it working in an environment
where the Chameleon service is doing most of the legwork.   
So my questions are: 
1)  Is there a way to feed Chameleon the same info that is in the Context
file from say a XML recordset stream from a database?  If so, can someone
point me to the code/files where Chameleon opens and reads the context.xml
file it is passed?
2) Does anybody have examples of Legend Widgets that they wrote that may be
similar to what I am trying to do? 
3) Can someone direct me on which way I should go if I have to create my own
widget? Is there any code I could start with?


Any help or suggestions is appreciated. 
Thanks a bunch! 
Dave A.