How do I show my WMS layer using QGIS server and OpenLayers?

Question

I've installed QGIS server and it works fine. I've put qgs file in the server folder dir and using "Add WMS layer" from QGIS I manage to view the qgs file.

This is how I use GetCapabilities for example: http://www.localhost.com/qgis/qgis_mapserv.fcgi.exe?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities&map=D:/OSGeo4W/apps/qgis/bin/MyLondon.qgs&

Now my problem is that in all OpenLayers WMS examples, adding WMS layer looks like this:

layer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
         "http://vmap0.tiles.osgeo.org/wms/vmap0",
          {layers: 'basic'}
           );

How do I convert my WMS to this format? Where in the URL I set the project name and where the layer name?

Answer 1

I've posted a solution that works for me on http://underdark.wordpress.com/2012/03/30/qgis-server-on-ubuntu-step-by-step/. Adjusted to your information, it would be something like:

wms = new OpenLayers.Layer.WMS(
'london_basic', "http://www.localhost.com/qgis/qgis_mapserv.fcgi.exi",
{
    layers: 'basic', 
    format: 'image/png',
    map: 'D:/OSGeo4W/apps/qgis/bin/MyLondon.qgs',
}, 
{
    buffer: 1, 
    isBaseLayer: true, 
    graphicZIndex: 0, 
}
);

Answer 2

The map parameter is part of the service endpoint URL, so the syntax would be like:

layer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
   "http://localhost/qgis/qgis_mapserv.fcgi.exe?map=D:/OSGeo4W/apps/qgis/bin/MyLondon.qgs&",
    {layers: 'basic'}
);

To convert to a more friendly endpoint URL like http://localhost/qgis/qgis_mapserv.fcgi.exe? add a SetEnvIf parameter to your Apache config, something like:

SetEnvIf Request_URI "/qgis/qgis_mapserv.fcgi.exe" MS_MAPFILE=D:/OSGeo4W/apps/qgis/bin/MyLondon.qgs