I'm having a devil of a time working on this one.
My setup:
* Linux server ( Fedore Core 3, Apache, etc. )
* MapServer ( 4.2.5 )
* MapLab w/ gMap Factory ( 2.2.1 )
* PHP/MapScript ( 1.194.2.6 )
* PostGIS-enabled postgreSQL database
Things are running smoothly for simple map creation. I can edit maps, add
PostGIS layers, etc. easily. But I'm just a bit stumped when it comes to
making the map file's DATA attribute a variable and passing a SQL query
string to it.
My ultimate goal is to take user input (in the form of dropdown lists - but
for right now I'm using a simple text box), create a query string from this
input, and then use it as the DATA attribute.
So far, I have made a form element in the file automatically created by
gMap Factory ( <project_name>_contents.php ) which adds the string :
sqlstring="the_geom from postgis_table"
to the URL when a submit button is clicked.
How can I get this string to be the DATA attribute in my <project_name>.map
file?
The "MapServer MapFile Reference" mentions the ability to use variable
substitution in map files, which seems like the best route to
take. However, it also states that "if you are using MapScript, you will
have to code the substitution logic in your application yourself (By
writing your own pre-processor)."
I've found a few references here and there that touch on using percent
signs to create a variable like %DATA% in the map file, but no concrete
examples on how to actually pass the data to such a variable using
something like MapScript.
Does anybody have some insight?
Thanks a ton.
--Damon
brog at mail dot utexas dot edu
