[OpenLayers-Users] OpenLayers and Projections

[Erik Uzureau]

Scott,

I asked one of my colleagues and he understands the problem a little better.

"Here's the deal: the data he's using has no EPSG code. that means he
can't select a SRS that will work: he has to leave the property out.
However, with the current codebase, it's not possible to leave out the
SRS entirely: if you set it to 'null', it gets replaced by the default
of EPSG:4326."

So this is just a question of making a small change to our codebase to
make the addition of the SRS parameter optional. We should be taking
care of this later today or tomorrow at the latest....

You can keep an eye on the timeline, but anyways I'll send you an email
when it gets committed. :-)

-Erik


On 7/14/06, Scott Knutti <sknutti at sanz.com> wrote:
> Erik,
>
> I'm sorry to report that this technique did not work either.  Can
> OpenLayers handle a Proj WKT definition?
>
> Thanks,
> Scott
>
> Erik Uzureau wrote:
> > I have to run now. Will be back on tomorrow.... but try this:
> >
> >  var map = new OpenLayers.Map( $('map') );
> > var layer = new OpenLayers.Layer.WMS("OpenLayers WMS",
> >   "http://servername/cgi-bin/mapserv",
> >   {map: "path_to_mapfile", layers: "status", format: "image/png",
> > transparent: "true"},
> > { srs: "+proj=aea +ellps=GRS80 +datum=NAD83
> > +lon_0=96w +lat_0=37.5n +lat_1=29.5n +lat_2=45.5n +units=m
> > +a=6378137"} );
> > map.addLayers(layer);
> >
> >
> > hope it helps... :-)
> > erik
> >
> > On 7/13/06, Scott Knutti <sknutti at sanz.com> wrote:
> >> Sure, here's the code I have that returns the msWMSLoadGetMapParams():
> >> Invalid SRS given error...
> >>
> >>   var map = new OpenLayers.Map( $('map') );
> >>   var layer = new OpenLayers.Layer.WMS("OpenLayers WMS",
> >>     "http://servername/cgi-bin/mapserv",
> >>     {map: "path_to_mapfile", layers: "status", format: "image/png",
> >> transparent: "true", srs: "+proj=aea +ellps=GRS80 +datum=NAD83
> >> +lon_0=96w +lat_0=37.5n +lat_1=29.5n +lat_2=45.5n +units=m
> >> +a=6378137"} );
> >>   map.addLayers(layer);
> >>
> >> The Proj WKT is what I use in my mapfile and is also the projection the
> >> data is in.
> >>
> >> Thanks,
> >> Scott
> >>
> >> Erik Uzureau wrote:
> >> > Hi Scott,
> >> >
> >> > The default projection in OpenLayers is EPSG:4326.
> >> > But you can overrride that by specifying a 'projection' value in the
> >> > layer options (or the map options, if you wish)
> >> >
> >> > example:
> >> >
> >> >            var map = new OpenLayers.Map( $('map') );
> >> >            var layer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
> >> >                    "http://labs.metacarta.com/wms/vmap0",
> >> >                    {layers: 'basic'}
> >> >                    {projection: 'chicken'});
> >> >            map.addLayer(layer);
> >> >
> >> >
> >> > If this doesn't work, please write back. And please include either a
> >> > link to live code or
> >> > some code snippets and detailed errors. :-)
> >> >
> >> > -Erik
> >> >
> >> >
> >> > On 7/13/06, Scott Knutti <sknutti at sanz.com> wrote:
> >> >> Hi,
> >> >>
> >> >> I am wondering how OpenLayers handles projections.  I have some
> >> >> shapefile data in an Albers Equal Area Conic projection that does not
> >> >> show up in the EPSG database.  How do I specify that projection in
> >> >> OpenLayers?  I have used the Proj WKT in my mapfile, but I get an
> >> >> invalid SRS given when I try to use it with OpenLayers. How can I
> >> get my
> >> >> data to display in the projection it is already in?
> >> >>
> >> >> Thanks,
> >> >> Scott Knutti
> >> >> _______________________________________________
> >> >> Users mailing list
> >> >> Users at openlayers.org
> >> >> http://mailman-viper.python-hosting.com/listinfo/users
> >> >>
> >>
>