[mapserver-users] Dynamic WMS Service - Projections problem?

joanne.mcgraw at sympatico.ca joanne.mcgraw at sympatico.ca
Tue Feb 8 17:23:32 EST 2011


Beautiful, yes. After a bit of fudging and adjusting (because I don't actually have access to the actual server I'm really trying to use), I managed to get it "not" working on my localhost as it was "not" working on that server. On localhost I was able to put the DEBUG in the map file and see the results. It told me that it couldn't resolve the host (Host not found). 

There is an extra '/' in the path being put in the WMC. Instead of http://<domain>/... in the OnlineResource, it is getting http:///<domain>/... during the process. Now I just have to figure out why that's happening but I'm sure it won't be difficult.

Thank you for reminding me of the DEBUG.

Cheers,
jtm

> From: jean-francois at gigand.fr
> Date: Tue, 8 Feb 2011 22:32:59 +0100
> Subject: Re: [mapserver-users] Dynamic WMS Service - Projections problem?
> To: joanne.mcgraw at sympatico.ca
> CC: mapserver-users at lists.osgeo.org
> 
> Hi,
> 
> Have you checked the MapServer logs?
> 
> To enable it, set the env variable MS_ERRORFILE to the log file path
> and MS_DEBUGLEVEL to "5".
> It will detail interesting details about how your layers are built.
> 
> Jeff
> 
> 
> 2011/2/8 myOpenLayersUName <joanne.mcgraw at sympatico.ca>:
> >
> > First, the background...
> >
> > I have a WMS Service that has an "empty" point layer in it. I use it to
> > display labels at dynamically generated coordinates by passing x,y within
> > the request. For example:
> >
> > http://<domain>/ogc/mapserv?map=/path/fenceLabelWms_en.map&map.layer[fencelabel]=FEATURE
> > POINTS -105.5620661354989 51.14394472618872 END TEXT "Fence 1"
> > END&map.layer[fencelabel].class[0]=COLOR 255 0 0
> > END&map.layer[fencelabel].class[0]=LABEL COLOR 255 0 0 SIZE 10 POSITION UR
> > END&LAYERS=fencelabel&mode=map
> >
> >
> > The entire map file is as follows:
> >
> > MAP
> >  NAME "fenceLabelWms_en"
> >  FONTSET "../../../mapserv/etc/fonts.txt"
> >  SYMBOLSET "../../../mapserv/etc/symbols.sym"
> >  SIZE 400 300
> >  IMAGETYPE PNG
> >  IMAGECOLOR 255 255 255
> >  RESOLUTION 96
> >  EXTENT -141.5 41.5 -51.5 83.5 # all of Canada
> >  UNITS METERS
> >  PROJECTION
> >    "init=epsg:4269" # lat/long
> >  END
> >  WEB
> >    METADATA
> >      "wms_srs" "EPSG:42304"
> >    END
> >  END
> >
> >  OUTPUTFORMAT
> >    NAME png
> >    DRIVER 'GD/PNG'
> >    MIMETYPE 'image/png'
> >    IMAGEMODE PC256 #RGB
> >    FORMATOPTION "INTERLACE=OFF"
> >    EXTENSION 'png'
> >    TRANSPARENT ON
> >  END
> >
> >  LAYER
> >    NAME "fencelabel"
> >    STATUS ON
> >    TYPE point
> >    CLASS
> >      SIZE 0
> >      COLOR 0 0 0
> >      LABEL
> >        TYPE truetype
> >        FONT verdana
> >        ANTIALIAS false
> >      END
> >    END
> >  END
> > END
> >
> >
> > A number of  applications use this WMS and each has its own projection but,
> > as in the request above, all pass the x,y as lat/long (EPSG:4269). The MAP
> > METADATA's "wms_srs" lists the supported projections (for the purposes of
> > this example, I'm simplifying by only including EPSG:42304).
> >
> >
> > So, this allows me to provide the point coordinates in lat/long, but display
> > them using the projection from the application itself. For example:
> >
> > http://<domain>/ogc/mapserv?map=/path/fenceLabelWms_en.map&map.layer[fencelabel]=FEATURE
> > POINTS -105.5620661354989 51.14394472618872 END TEXT 'Fence 1'
> > END&map.layer[fencelabel].class[0]=COLOR 255 0 0
> > END&map.layer[fencelabel].class[0]=LABEL COLOR 255 0 0 SIZE 10 POSITION UR
> > END&LAYERS=fencelabel&FORMAT=image/png&SRS=EPSG:42304&TRANSPARENT=true&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application/vnd.ogc.se_inimage&BBOX=-2903297.000,-789911.0000,3431059.000,3959683.000&WIDTH=1219&HEIGHT=601
> >
> >
> > Knowing this, I can define this "dynamic" layer within a WMC <Layer> tag and
> > load it into an OpenLayers Map (whose projection is set to EPSG:42304 and
> > extents encompass all of Canada). The WMC definition for the above layer is
> > as follows (we use a batch script to set the path to the MapServer
> > executable and MAP file, "fenceLabelWms_en"):
> >
> > <Layer queryable="0" hidden="0">
> >    <Server service="OGC:WMS" version="1.1.1">
> >        <OnlineResource xlink:type="simple"
> > xlink:href="http://<domain>/ogc/fenceLabelWms_en?map.layer[fencelabel]=FEATURE%20POINTS%20-105.5620661354989%2051.14394472618872%20END%20TEXT%20'Fence%201'%20END&amp;map.layer[fencelabel].class[0]=COLOR%20255%20105%200%20END&amp;map.layer[fencelabel].class[0]=LABEL%20COLOR%20255%20105%200%20SIZE%2010%20POSITION%20LR%20END"/>
> >    </Server>
> >    <Name>fencelabel</Name>
> >    <Title>Fence 1</Title>
> >    <SRS>EPSG:42304</SRS>
> >    <FormatList>
> >        <Format current="1">image/png</Format>
> >    </FormatList>
> >    <Extension>
> >        <ol:maxExtent minx="-2903297.000" miny="-789911.0000"
> > maxx="3431059.000" maxy="3959683.000"/>
> >        <ol:transparent>true</ol:transparent>
> >        <ol:numZoomLevels>5</ol:numZoomLevels>
> >        <ol:units>m</ol:units>
> >        <ol:isBaseLayer>false</ol:isBaseLayer>
> >        <ol:displayInLayerSwitcher>false</ol:displayInLayerSwitcher>
> >        <ol:singleTile>true</ol:singleTile>
> >    </Extension>
> > </Layer>
> >
> >
> > Okay, everything works fine up to this point. The fence label WMS is
> > displayed in the OpenLayers Map correctly in relation to the other layers it
> > contains, all of which have projections of EPSG:42304.
> >
> >
> > Now, the problem ...
> >
> > I’d like to print the image displayed to the user. To do this, I have
> > another "empty" MAP file that I use to print the WMC; the same WMC I loaded
> > into OpenLayers. The entire contents of this MAP file are:
> >
> > MAP
> >  NAME "wmsContextServer"
> >  FONTSET "../../../mapserv/etc/fonts.txt"
> >  SYMBOLSET "../../../mapserv/etc/symbols.sym"
> >  SIZE 400 300
> >  STATUS ON
> >  IMAGETYPE PNG
> >  IMAGECOLOR 255 255 255
> >  EXTENT -2338951 -800000 3008692 3900000
> >  UNITS METERS
> >  CONFIG "CGI_CONTEXT_URL" "1"
> >  PROJECTION
> >    "init=epsg:42304"
> >  END
> >
> >  RESOLUTION 96
> >
> >  REFERENCE
> >    # Parameter settings NOT to change
> >    STATUS          ON
> >    COLOR           -1 -1 -1
> >    OUTLINECOLOR    255 0 0
> >    # Parameter settings that will change if you replace the default
> > 'refmap.png'
> >    IMAGE           "../htdocs/images/refmap.png"
> >    SIZE            100 74
> >    EXTENT          -2.2e+006 -712631 3.0728e+006 3.84e+006
> >  END # REFERENCE
> >
> >  SCALEBAR
> >    STATUS EMBED
> >    INTERVALS 1
> >    POSITION LL
> >    TRANSPARENT true
> >    UNITS kilometers
> >    STYLE 1
> >    SIZE 100 7
> >    LABEL
> >      SIZE small
> >    END
> >  END
> >
> >  WEB
> >    INCLUDE "../../../mapserv/conf/imagepath.inc.map"
> >    METADATA
> >      # Used for App Page Title
> >      "wms_title" "WMC Context Client"
> >      "wms_connectiontimeout" "60"
> >    END
> >  END
> >  OUTPUTFORMAT
> >    NAME png
> >    DRIVER 'GD/PNG'
> >    MIMETYPE 'image/png'
> >    IMAGEMODE RGB
> >    FORMATOPTION "INTERLACE=OFF"
> >    EXTENSION 'png'
> >    #TRANSPARENT ON
> >  END
> >
> >  OUTPUTFORMAT
> >    NAME gif
> >    DRIVER 'GD/GIF'
> >    MIMETYPE 'image/gif'
> >    IMAGEMODE RGB
> >    FORMATOPTION "INTERLACE=OFF"
> >    EXTENSION 'gif'
> >  END
> >
> > END
> >
> >
> > Unfortunately, the "dynamic" WMS layer doesn't appear in the output image. I
> > can use the following URL to get an image of all the other layers in the WMC
> > successfully, but the fence label is not shown and there is no error
> > message:
> >
> > http://<domain>/ogc/mapserv?map=/path/wmsContextServer.map&mode=map&context=http://<domain>/contexts/WMCwFenceLabels.xml&layers=all
> >
> >
> >
> > I'm guessing MapServer is getting a blank image when it's assembling the
> > layers for the output image and I'm further guessing that this is the result
> > of the projections somehow getting out of whack somewhere along the line.
> > I'm thinking that the point is being evaluated as not actually existing
> > within the extents of the output image being generated, perhaps? But, I
> > can't guess why this would be the case. There is no question that it does
> > fall within the extents (as witnessed by loading the same WMC in
> > OpenLayers).
> >
> >
> > As it is now, I am completely stuck as to what the problem might be. Can
> > anyone suggest anything that might help me narrow down exactly what the
> > problem is or a direction I can investigate further?
> >
> > --
> > View this message in context: http://osgeo-org.1803224.n2.nabble.com/Dynamic-WMS-Service-Projections-problem-tp6004893p6004893.html
> > Sent from the Mapserver - User mailing list archive at Nabble.com.
> > _______________________________________________
> > mapserver-users mailing list
> > mapserver-users at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/mapserver-users
> >
 		 	   		  
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