[OpenLayers-Users] Display Point from Polygon WFS

[Florent Gravin]

I use PostGIS database, and then, geoserver.

for exemple, i have a table called "countries", with population, density 
attribues, whom geometry is polygon.
if i understand, you suggest to create a new table "countries_point" from 
countries, using ST_Centroid to get point as the geom column, and duplicate 
attributes (population, density)
so i have to similars tables... and then i call a request WFS on 
"countries_point" ?


I guess it works, but it's not very good to have a redundance of 2 tables... 
(updates...)
there is no tools like WFS special parameter, or openlayers tips to display 
polygon feature as point ? (we can do it easly with WMS)

thks

----- Original Message ----- 
From: "Vivien Deparday" <vivien.deparday at gmail.com>
To: "floflo" <florent.gravin at bluecham.net>
Cc: <users at openlayers.org>
Sent: Thursday, April 02, 2009 11:21 AM
Subject: Re: [OpenLayers-Users] Display Point from Polygon WFS


> Hi,
>
> I'm not sure what technology you use on the server side but if you use a 
> spatial database like PostGIS, you can use the function ST_Centroid( 
> geometry ) in the database and then directly request the centroids instead 
> of the polygons.
> Cheers,
>
> Vivien
>
> floflo wrote:
>> Hi,
>>
>> i request a WFS query on a layer full of complex polygon.. rendering is 
>> too slow
>> anyway, I just want to display a POINT for each POLYGON (in the middle)
>>
>> purpose: display proportionnal symbol from an attribute of a polygon 
>> layer (exemple, layer : country, propSymbol on Population)
>>
>> do you have any issue ?
>> thanks
>>
>