If you're doing point queries MapServer/MapScript can do this for you.
You do a
mapObj.queryByPoint with the MS_SINGLE mode and then the function will
identify
the closest feature (considering TOLERANCEs!) in the top-most ACTIVE
layer.

This site uses this to it's advantage...

  http://www.dnr.state.mn.us/maps/compass.html

A query drops through the layers until a match is hit.

Even with other geometry types based on what was described you can
probably do
it pretty easily. You'd use one of the other query methods and then once
the query
is done loop through your layer stack backwards (e.g. starting at the
top) and stop
when you find one with results.

Steve

>>> Paul james <[email protected]> 05/20/09 7:56 AM >>>
Thanks Pano...
But It́s not that simple...
What I need is figure out what LAYER was clicked...

Paul

On Wed, May 20, 2009 at 6:43 AM, Pano Voudouris
<[email protected]>wrote:

>  Probably don’t understand what exactly you are trying to achieve here
but
> it is not as simple as map.getLayer(0) to get the topmost layer? And
once
> you have the layer object use one of the query function to select the
> record? E.g.  myLayerObj.queryByPoint ?
>
>
>
> Pano
>
>
>
> *From:* [email protected] [mailto:
> [email protected]] *On Behalf Of *Paul james
> *Sent:* 19 May 2009 21:46
> *To:* [email protected]
> *Subject:* [mapserver-users] Get the nearest layer with mapscript...
>
>
>
> Hello guys...
> I have several layers (lines, points, poly) ...
> Ím developing a measure tool... User can click on map and I have to
> select that layer to calculate de Area with postgis...
>
>  Ím trying to do that WITHOUT using "LAYER ACTIVE SYSTEM"...
>
>  Is That possible using mapscript? How Can I find the nearest and
toppest
> layer ?
>
> Thanks!
>
> Paul
>
> _______________________________________________
> mapserver-users mailing list
> [email protected]
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>
>

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