[mapserver-users] How to get Layers By Group

[Venkat Rao Tammineni]

Dear Gregor,


Thanks for your great response.

The below is my code to retrieve layer based on layer index and I am
populating into checkboxes

for (int i = 0; i < map.numlayers; i++)
{
       layer = map.getLayer(i);
       cbLayer.Items.Add(layer.name); //checkbox
       if (layer.status == (int)mapscript.MS_ON)
        {
             cbLayer.Items[i].Selected = true;   //check box
        }
}


Like that how can I populate layer names based on group into check box or
treeview.


Thanks
Venkat.



-----Original Message-----
From: Gregor at HostGIS [mailto:gregor at hostgis.com] 
Sent: Friday, February 06, 2009 9:31 AM
To: Venkat Rao Tammineni
Cc: mapserver-users at lists.osgeo.org
Subject: Re: [mapserver-users] How to get Layers By Group

Venkat Rao Tammineni wrote:
>    How  can I retrieve layers  by Group Name. And how to loop these 
> layers based on group. Where I can able to  switch on and swatch off the 
> layers based on Group.

A group is just a "fake layer" with many layers. You request a group in 
the same way as you would a layer; the only change is that you use the 
group name and will get all the layers mixed together.

Example:

LAYER
   NAME "roads"
   GROUP "usamap"
END
LAYER
   NAME "lakes"
   GROUP "usamap"
END
LAYER
   NAME "cities"
   GROUP "usamap"
END

I would then request "layers=usamap" and magically get all three layers 
merged into one request.


> I have Group property in my mapfile .but I don't 
> know how to get layers and populate some control

As to generating a control, that's the same as with layers as well 
except that you would use getAllGroupNames() instead of 
getAllLayerNames() But that depends on your own programming style and goals.

-- 
Gregor Mosheh / Greg Allensworth    BS, A+, Network+, Security+, Server+
System Administrator, Lead Programmer
HostGIS development & hosting services, http://www.HostGIS.com/

"Remember that no one cares if you can back up,
  only if you can restore." - AMANDA