[mapserver-users] turning off classes

[Stephen Lime]

Answers---

 - No, not with the CGI version. In mapscript you could manage the classes yourself and create a custom layer on-the-fly with only the requested classes. You could also muck with with class colors or expressions to render them useless. I can easily add a status option to an individual class and can alter the rendering and query code to honor it. I can't quickly add a programatic may to toggle class status from the CGI program. Please add this to Bugzilla as a feature request.

- There is a performance hit, how much depends on the data and how many layers you need to break out. For moderately sized datasets and a few additional layers you probably won't notice. On large datasets, if this much control is needed then I would argue that the shapefile itself should be split into different layers.

Steve

Stephen Lime
Internet Applications Analyst

Minnesota DNR
500 Lafayette Road
St. Paul, MN 55155
651-297-2937
>>> Puneet Kishor <pkishor at GeoAnalytics.com> 07/24/01 13:18 PM >>>
I have one layer with many classes shaded thematically...

two questions --

1. is it possible to programmatically turn on/off individual classes
2. if #1 above is not possible, and I have to separate the classes into
separate layers, is there any performance impact positively or negatively?

Many tia,

pk/

--
Puneet Kishor 
pkishor at geoanalytics.com
www.geoanalytics.com

GeoAnalyics, Inc.
1716 Fordem Ave
Madison WI 53704