Hi all,
I did same test lately with the GetFeatureInfo function. Sometimes I find it a little hard to click on an exact point on the map to get informations.
So I'm wondering if there is a parameter I can add to a query to give it a bigger radius.
Someone told me that this parameter exist on mapserver as "TOLERANCE". The query is then made on a bigger radius from the click point.
So I want to know if there is something similar on Geoserver 
Regards,
Marc
Marc Desharnais ha scritto:
Hi all,
I did same test lately with the GetFeatureInfo function. Sometimes I find it a little hard to click on an exact point on the map to get informations.
So I'm wondering if there is a parameter I can add to a query to give it a bigger radius.
Someone told me that this parameter exist on mapserver as "TOLERANCE". The query is then made on a bigger radius from the click point.So I want to know if there is something similar on Geoserver
Unfortunately the OGC spec does not foresee such a parameter, but
I think we should add it as a custom extension, I too have sometimes
troubles clicking on the right spot... but this is also the consequence
of how GetFeatureInfo is implemented.
A user sees a point depicted as a 10 pixels radius circle and thinks
he can click anywhere in the circle to get infos, too bad this is
far from reality... the GetFeatureInfo code is basically a GetFeature
with a bbox spanning the pixel clicked and the neighbours, that is,
a 3 pixel wide bbox. So, to pick the point you really have to click
near the location of the real geometry.
Having GetFeatureInfo respond in a natural way is in the plans, but it's
not trivial (adding tolerance would be much easier). See also:
http://jira.codehaus.org/browse/GEOS-1008
Cheers
Andrea
Hi Andrea,
Thank you for your clear answer. I can see there's work in progress and you guys are doing great job.
Thanks a lot,
Marc
Andrea Aime wrote:
Marc Desharnais ha scritto:
Hi all,
I did same test lately with the GetFeatureInfo function. Sometimes I find it a little hard to click on an exact point on the map to get informations.
So I'm wondering if there is a parameter I can add to a query to give it a bigger radius.
Someone told me that this parameter exist on mapserver as "TOLERANCE". The query is then made on a bigger radius from the click point.So I want to know if there is something similar on Geoserver
Unfortunately the OGC spec does not foresee such a parameter, but
I think we should add it as a custom extension, I too have sometimes
troubles clicking on the right spot... but this is also the consequence
of how GetFeatureInfo is implemented.A user sees a point depicted as a 10 pixels radius circle and thinks
he can click anywhere in the circle to get infos, too bad this is
far from reality... the GetFeatureInfo code is basically a GetFeature
with a bbox spanning the pixel clicked and the neighbours, that is,
a 3 pixel wide bbox. So, to pick the point you really have to click
near the location of the real geometry.Having GetFeatureInfo respond in a natural way is in the plans, but it's
not trivial (adding tolerance would be much easier). See also:
http://jira.codehaus.org/browse/GEOS-1008Cheers
Andrea