Hi, Is there anybody out there that can help me with this very simple configuration? Im new to WMS and Im learning about it right now. Im not completely new to programming though; I have experience in C, PL/SQL, MapBasic and a bit of JavaScript and HTML. Im into GIS and used Oracle Spatial with MapInfo software at work. I only now started to appreciate open source.
I decided to go onto practice straight away and opted for the following configuration: PostgreSQL/PostGIS (this is an excellent db and the documentation is impressive!) MapServer for rendering images and Openlayers as a simple way to interact with the map/information. Everything installed locally. All I need is some sort of Hello World style example, some sort of launch pad where I can add or change bit and pieces as I learn. Seeing something actually working would give me the confidence to going through all the details. It should work with this configuration and I would be really grateful if someone could help me with this. I have loaded some vector data into Postgres, some polylines (or linestrings) representing road network. This is referenced to British National Grid (BNG) srid: 27700. The table has been spatially indexed. Heres where I can smell some trouble. MapServer successfully outputs a png image with the following map file: MAP IMAGETYPE PNG EXTENT 525300 179800 536700 187600 SIZE 800 600 SHAPEPATH "/ms4w/apps/TestMaps/FirstTest" IMAGECOLOR 192 192 192 UNITS METERS LAYER CONNECTIONTYPE postgis NAME "tlrn_network" CONNECTION "user=??? password=??? dbname=mapping host=localhost" DATA "wkb_geometry FROM net" STATUS ON TYPE LINE CLASS COLOR 0 0 0 END METADATA "WMS_SRS" "EPSG:BNG" END PROJECTION "init=epsg:27700" END END END I tested this firefox and the following URL: http://localhost/cgi-bin/mapserv.exe?map=/ms4w/apps/TestMaps/FirstTest/tlrn.map&layer=tlrn_network&mode=map So far so good, but heres the trouble: <html> <head> <script src="http://openlayers.org/api/2/OpenLayers.js";></script> </head> <body> <div style="width:100%; height:100%" id="map"></div> <script defer="defer" type="text/javascript"> var mymap = new OpenLayers.Map('map'); var mylayer = new OpenLayers.Layer.WMS( "OpenLayers WMS", "http://localhost/cgi-bin/mapserv.exe?",{layers: 'tlrn_network',map:'/ms4w/apps/TestMaps/FirstTest/tlrn.map'},{projection: "EPSG:BNG"}); mymap.addLayer(mylayer); mymap.zoomToMaxExtent(); </script> </body> </html> It just doesnt work. Openlayers kind of attempt to display the image, it shows the correct background color. However, instead of my road network, it shows the following error message on each tile: MsWMSLoadGetMapParams(): WMS server error. Cannot set new SRS on a map that doesnt have any projection set. Please make sure your mapfile has a projection defined at the top level. Well, obviously my map file has no defined projection at top level. It is only defined at the layers level (and probably wrongly). Whenever I attempt to do at the Map top level it seems that things get only worse or no change at all. When I get rid of the metadata, for example # METADATA # "WMS_SRS" "EPSG:BNG" # END the message changes to: msWMSLoadGetMapParams(): WMS server error. Invalid SRS given : SRS must be valid for all requested layers. Im stuck! As I said all I need is something that works and I can use as a base. Ill go away and practice with all this without harassing the entire community (well, for a while at least!). Many thanks Andy
