CGI vs. WMS

[Jim Cser]

All the comments were helpful, thanks.   I was not familiar with the
"mode=map" option in a URL, since all the books I read only gave
examples of posting the CGI variables through a form.  For our current
WMS, we are already using CF to create all our URLs on the fly, so it
should be a small step to translate from back to the CGI versions.  

It's easy to get caught up in all the hype about Web Services, so it's
good to be reminded that there are other ways of doing things.
-Jim


>>> Paul Ramsey <pramsey at refractions.net> 07/07/06 12:33 PM >>>
Jim,

David's advice is right on the money... build up a mode=map URL in your

scripting environment (CF, PHP, whatever) and then fire that off to the

mapserver backend.  Using WMS mode is actually more restrictive than 
just using the Mapserver CGI variable controls 
<http://mapserver.gis.umn.edu/docs/reference/cgi/controls> with which 
you can actually do many/most of the things people lean on mapscript 
for. (Things like dynamically changing aspects of styling or filtering

or even the PostGIS DATA statements (feel the power!)).

We've used mode=map + cgi variable controls to build some pretty 
complicated sites (dynamically do thematic mapping of US census data, 
for example, changing variables, color themes, categorization, etc on 
the fly) without using mapscript.

Paul

Fawcett, David wrote:
> Jim, 
> 
> For adding simple mapping to CF apps, I have used CF to dynamically
> build a URL request that I then call with <CFHttpRequest>.  I use
> mode=map, so the images don't go to the tmp directory.  
> 
> I am guessing that going to a WFS layer for your data source may
slow
> down your app.  
> 
> David.
> 
> -----Original Message-----
> From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU]
On
> Behalf Of Jim Cser
> Sent: Friday, July 07, 2006 1:15 PM
> To: MAPSERVER-USERS at LISTS.UMN.EDU 
> Subject: [UMN_MAPSERVER-USERS] CGI vs. WMS
> 
> 
> What are the pro and cons of using WMS over CGI MapServer?   Does
anyone
> here have any direct experience with both?
> 
> We have a Cold Fusion web application that displays a few maps, with
> only simple pan/zoom functionality needed * it's not a "GIS-like"
site.
> Our previous MapServer apps have used CGI MapServer, but for this app
we
> decided to experiment with implementing a WMS service.  We're a CF
shop,
> otherwise we might try PHP or Java mapscript.  Our map layers are
coming
> from PostGreSQL/ PostGIS, for what it's worth.
> 
> The WMS was nice because of the detailed diagnostics returned on
errors,
> and for the fact that we aren't filling up a directory with
> image files.   On the other hand, the lack of ability to dynamically
> control the symbology is becoming a show-stopper, and with CGI we can
at
> least throw it a URL containing terms like
> "map_layername_class_expression=('[PROJECT_ID]'='89' ".
> 
> Similarly, will switching to a WFS service, or calling a WFS layer
in
> the WMS map file have any advantages?  I was looking into filter
> encoding, but was getting lost by the distinction between returning
> features and returning an image.  
> 
> At this point in our development cycle, it would be preferable to
"drop
> in" some functionality, rather than re-write a lot of code, but as I
> said above, dynamic symbology is the driver.
> 
> Thanks,
> Jim Cser