[Chameleon] chameleon and postgis implementation

[Anand Akmanchi]

my greetings to the chameleon team and list members

I installed the postgis demo where one is able to dynamically query
(bc_voting areas example)

in the example it is achieved by storing the sql query in html <textarea> object

and in the mapfile, the postgis layer contains (%sql%) in the data definition
and the %sql% is substituted with the sql query string stored in the
<textarea> object

its a great example of the power of postgis and mapserver

my question is:

how can we do this with chameleon?

for example a user selects a field from a dropdown box, clicks update
the sql query is built using the fieldname from dropdown box
and passed to the mapfile where (%sql%) is the data definition of the
postgis layer
the fieldname is substituted for classitem in mapfile containing generic classes
and the map is displayed

I am not quite proficient with PHP programming
and interested in learning as I go about this

you guys make it look so easy!

I am eagerly waiting your replies.

great day

-- 
Anand Akmanchi
PhD Student, Department of Environmental Science
University of Pune
http://www.unipune.ernet.in/dept/geography/anandakmanchi.htm