SV: [mapserver-users] Classitems selection

Fawcett, David David.Fawcett at state.mn.us
Thu Aug 13 07:07:46 PDT 2009


Christy is right.  

With a reasonably small number of items, either the IN syntax or the regular expression will work.  

I use the IN syntax to classify 87 counties in an app and it runs fast.  A recent comparison done by Adrian Popa indicates that the regular expression syntax is faster.  

Here is the thread:  http://lists.osgeo.org/pipermail/mapserver-users/2009-July/062071.html

David.

-----Original Message-----
From: mapserver-users-bounces at lists.osgeo.org [mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf Of Christy Nieman
Sent: Thursday, August 13, 2009 9:01 AM
To: Lars Westerlind
Cc: mapserver-users at lists.osgeo.org
Subject: Re: SV: [mapserver-users] Classitems selection


Hi,

When you say that you could very well use expressions, do you mean 
regular expressions? In my experience, unless you are working with a 
very large data set they're fine.

E.g.
CLASSITEM "flavour"
...
EXPRESSION /cherry|mango|lime/

Christy

Lars Westerlind wrote:
>
> AFAIK currently I write
>
> CLASSITEM "flavor"
>
> ...
>
> EXPRESSION "cherry"
>
> Suggested extension would be to allow for
>
> CLASSITEM
>
> ...
>
> EXPRESSION "cherry","mango","lime"
>
> But really, syntax is not my concern. A could very well use
> expressions, but the documentation says they are not good for 
> performance. And my first question is if I've missed something?
>
> ----------------------------------------------------------------------
> --
>
> *Från:* Fawcett, David [mailto:David.Fawcett at state.mn.us]
> *Skickat:* 13 August 2009 15:39
> *Till:* Lars Westerlind; mapserver-users at lists.osgeo.org
> *Ämne:* RE: [mapserver-users] Classitems selection
>
> Do you mean something like ('[flavor]' IN ('cherry', 'mango', 'lime')?
>
>     -----Original Message-----
>     *From:* mapserver-users-bounces at lists.osgeo.org
>     [mailto:mapserver-users-bounces at lists.osgeo.org] *On Behalf Of
>     *Lars Westerlind
>     *Sent:* Thursday, August 13, 2009 2:39 AM
>     *To:* mapserver-users at lists.osgeo.org
>     *Subject:* [mapserver-users] Classitems selection
>
>     I use the CLASSITEM - EXPRESSION with string expression rather
>     much, which is also recommended for performance. But sometimes I
>     have a few values that could be shown in the same class. Wouldn't
>     it be a nice idea to allow for a commaseparated set/list of
>     strings to match?
>
> ----------------------------------------------------------------------
> --
>
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org 
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>   
_______________________________________________
mapserver-users mailing list
mapserver-users at lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users



More information about the MapServer-users mailing list