[Chameleon] ExpressionBuilder Help

[Paul Spencer]

If you don't know how it works, how can you know if it useful ;)

The ExpressionBuilder widget was built to work with WFS layers.  It 
attempts to determine information about the remote WFS layer in order to 
help the user generate an SLD Filter for the layer.  It will also work 
with WMS layers that are correctly configured to support SLD or to 
return a WFS layer and typename from the DescribeLayer WMS request.

GML does have the problem of being fairly bulky and is often not used 
for this specific reason.  However, you should be able to work with the 
WMS service just fine.

The SQLQuery widget will query a local database.  It outputs its results 
into a SharedResource widget so that other widgets can access the 
results of the query.  This is used with ExtractSR and Table widgets, 
which do something with the contents of a SharedResource.

Unfortunately, this is not documented very well (or at all ;)) so if you 
want to really know how to use this stuff, you will need to jump into 
the code at some point and try to understand it.

The folks on the list will help out as much as possible, but we can only 
really get you started ...

Cheers

Paul

RS wrote:
> hi list,
> I would like to know what's the proper use of the "ExpressionBuilder" 
> widget as it's really useful for my job.
> Must queriable layer be WMS or WFS? By the way, I'd like to know what's 
> the best way to have a wms/wfs connection without using mapserver as a 
> cgi. At the moment my datas are on postgis.
> I tried to configure a wfs connection but at any request too big gml 
> files are created that reduce speed and disk space. Is that right?
> Is there another widget to make queries, even simple like "address and 
> street number"? Maybe, the "SQLQuery" widget can be fine? By the way, 
> how does it work?
> Thanks for your patience
>   
> mapserver     4.4.1
> php_mapscript 4.4.1
> chameleon     2.0
> postgis       7.x
> 		
> 
> <http://www.incredimail.com/index.asp?id=416&lang=16>
> 
> 
> ----
> Email.it, the professional e-mail, gratis per te:clicca qui 
> <http://www.email.it/cgi-bin/start?sid=3>
> 
> Sponsor:
> Proteggi la tua moto dalle intemperie e... dagli sguardi indiscreti con 
> il Telo Coprimoto!
> Clicca qui <http://adv.email.it/cgi-bin/foclick.cgi?mid=2744&d=23-3>
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Chameleon mailing list
> Chameleon at lists.maptools.org
> http://lists.maptools.org/mailman/listinfo/chameleon