[Mapserver-users] Unique layer naming for WMS serving

Tue Aug 26 12:30:38 PDT 2003

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Brent -
=20
We've gone the GROUP route.  It works fine, and so far hasn't been an =
issue.  We may filter the WMS requests through a PHP script on the front =
end to pull out layers we don't want the user to select, but they'll =
still end up in the GetCapabilities document.  I'd be interested, too, =
in hearing from anyone with a better solution.
=20
     - Ed
Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
(978) 251-4242=20

-----Original Message-----
From: Brent Fraser [mailto:bfraser at geoanalytic.com]
Sent: Tuesday, August 26, 2003 3:03 PM
To: Daniel Morissette; mapserver-users
Subject: [Mapserver-users] Unique layer naming for WMS serving

Daniel,
=20
  I see that the WMS server portion of Mapserver renames the layers (by =
adding _01, _02, etc) to ensure the names are unique.  Is there a way to =
prevent that?
=20
=20
Some background...
=20
  I've used multiple layer definition for the same data (well almost the =
same data) in a map file to improve performance of rendering raster over =
a wide range of scales.  I'll preprocess the data by reampling the high =
resolution raster to medium and low res, then have three layers i the =
map file all named the same but visible only at a scale range approriate =
for their resolution.  As the user zooms in, Mapserver automatically =
switches to the higher resolution.  Works well with standard Mapserver, =
but using WMS protocol two of the layers get renamed.  This means that =
the user now needs to attach three layers and turn them on and off.
=20
    Another way I've used the same-layer-name feature is to use the same =
name for point, line, and polygon layers representing one theme such as =
cadastre or structures.  But I doubt if WMS clients would tolerate =
that...
=20
  I've tried grouping (GROUP and WMS_GROUP_TITLE) but it exposes the =
individual layer names to the user (it may have to do for now).
=20
  In my experiments with WMS_GROUP_TITLE, it seems that only one group =
is recognized per map file and that all layers will be included in it.  =
Is that true?
=20
Thanks for your comments!.
Brent Fraser
GeoAnalytic Inc.
Tel:(403) 213-2700
bfraser at geoanalytic.com
www.geoanalytic.com

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<DIV><SPAN class=3D304212919-26082003><FONT face=3DArial color=3D#0000ff =
size=3D2>Brent=20
-</FONT></SPAN></DIV>
<DIV><SPAN class=3D304212919-26082003><FONT face=3DArial color=3D#0000ff =

size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D304212919-26082003><FONT face=3DArial color=3D#0000ff =
size=3D2>We've=20
gone the GROUP route.  It works fine, and so far hasn't been an=20
issue.  We may filter the WMS requests through a PHP script on the =
front=20
end to pull out layers we don't want the user to select, but they'll =
still end=20
up in the GetCapabilities document.  I'd be interested, too, in =
hearing=20
from anyone with a better solution.</FONT></SPAN></DIV>
<DIV><SPAN class=3D304212919-26082003><FONT face=3DArial color=3D#0000ff =

size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D304212919-26082003><FONT face=3DArial color=3D#0000ff =

size=3D2>     - Ed</FONT></SPAN></DIV>
<DIV><SPAN class=3D304212919-26082003>
<P><FONT size=3D2>Ed McNierney<BR>President and Chief =
Mapmaker<BR>TopoZone.com /=20
Maps a la carte, Inc.<BR>73 Princeton Street, Suite 305<BR>North =
Chelmsford,=20
MA  01863<BR>ed at topozone.com<BR>(978) 251-4242 =
</FONT></P></SPAN></DIV>
<BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px">
  <DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT =
face=3DTahoma=20
  size=3D2>-----Original Message-----<BR><B>From:</B> Brent Fraser=20
  [mailto:bfraser at geoanalytic.com]<BR><B>Sent:</B> Tuesday, August 26, =
2003 3:03=20
  PM<BR><B>To:</B> Daniel Morissette; mapserver-users<BR><B>Subject:</B> =

  [Mapserver-users] Unique layer naming for WMS =
serving<BR><BR></FONT></DIV>
  <DIV><FONT face=3DArial size=3D2>Daniel,</FONT></DIV>
  <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
  <DIV><FONT face=3DArial size=3D2>  I see that the WMS server =
portion of=20
  Mapserver renames the layers (by adding _01, _02, etc) to ensure the =
names are=20
  unique.  Is there a way to prevent that?</FONT></DIV>
  <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
  <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
  <DIV><FONT face=3DArial size=3D2>Some background...</FONT></DIV>
  <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
  <DIV><FONT face=3DArial size=3D2>  I've used multiple layer =
definition for=20
  the same data (well almost the same data) in a map file to improve =
performance=20
  of rendering raster over a wide range of scales.  I'll preprocess =
the=20
  data by reampling the high resolution raster to medium and low res, =
then have=20
  three layers i the map file all named the same but visible only at a =
scale=20
  range approriate for their resolution.  As the user zooms in,=20
  Mapserver automatically switches to the =
higher resolution. =20
  Works well with standard Mapserver, but using WMS =
protocol two of=20
  the layers get renamed.  This means that the user now needs to =
attach=20
  three layers and turn them on and off.</FONT></DIV>
  <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
  <DIV><FONT face=3DArial size=3D2>    Another way I've =
used the=20
  same-layer-name feature is to use the same name for point, line, and =
polygon=20
  layers representing one theme such as cadastre or structures.  =
But I=20
  doubt if WMS clients would tolerate that...</FONT></DIV>
  <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
  <DIV><FONT face=3DArial size=3D2>  I've tried grouping (GROUP and =

  WMS_GROUP_TITLE) but it exposes the individual layer names to the user =
(it may=20
  have to do for now).</FONT></DIV>
  <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
  <DIV><FONT face=3DArial size=3D2>  In my experiments with =
WMS_GROUP_TITLE, it=20
  seems that only one group is recognized per map file and that all =
layers will=20
  be included in it.  Is that true?</FONT></DIV>
  <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
  <DIV><FONT face=3DArial size=3D2>Thanks for your =
comments!.</FONT></DIV>
  <DIV><FONT face=3DArial size=3D2>Brent Fraser</FONT></DIV>
  <DIV><FONT face=3DArial size=3D2>GeoAnalytic Inc.<BR>Tel:(403) =
213-2700<BR><A=20
  =
href=3D"mailto:bfraser at geoanalytic.com">bfraser at geoanalytic.com</A><BR><A=
=20
  =
href=3D"http://www.geoanalytic.com">www.geoanalytic.com</A></FONT></DIV><=
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