[fusion-dev] fusion and projection support

[Andreas Morf]

Mike
I investigated a little bit:

With the following Code, it is possible to get the EPSG code from the
Server:

Mapguide.js:

    convertWKT2EPSGRequest: function(wkt) {
        var r = new Fusion.Lib.MGRequest.MGEPSGfromWKT(wkt);
        Fusion.oBroker.dispatchRequest(r,
OpenLayers.Function.bind(this.processWKT2EPSGresponse, this));

    },
    
    processWKT2EPSGresponse: function (r) {
        if (r.responseText)
            alert(r.responseText);
    }, 

MGBroker.js

Fusion.Lib.MGRequest.MGEPSGfromWKT = OpenLayers.Class(Fusion.Lib.MGRequest,
{

    initialize : function( wkt ) 
    {
        this.initializeRequest();
        this.setParams( {
            operation : 'CS.CONVERTWKTTOEPSGCODE',
            version: '1.0.0',
            cswkt: wkt
        } );
    }
});

The main problem was that the server always returned a '0' as result for my
WKT:

PROJCS["SWISS",GEOGCS["LLCH1903",DATUM["CH-1903",SPHEROID["BESSEL",6377397.1
55,299.15281535],TOWGS84[660.0770,13.5510,369.3440,0.804816,0.577692,0.95223
6,5.66000000]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PR
OJECTION["Swiss_Oblique_Cylindrical"],PARAMETER["false_easting",600000.000],
PARAMETER["false_northing",200000.000],PARAMETER["latitude_of_origin",46.952
40555555556],PARAMETER["central_meridian",7.43958333333333],UNIT["Meter",1.0
0000000000000]]

There is a mapping file in CS-Map/Dictionaries which maps from CS-Code to
EPSG (NameMapper.csv) - the CS-Code 'SWISS' was not in there so I added the
following line:

21781,16,Autodesk,0,"SWISS",0,0,0,0,,

After restarting httpd (this took me quite a bit of time to find out...) the
server answers the request with the right EPSG-Code of 21781!

Greets
Andreas





> -----Original Message-----
> From: fusion-dev-bounces at lists.osgeo.org [mailto:fusion-dev-
> bounces at lists.osgeo.org] On Behalf Of Andreas Morf
> Sent: Wednesday, October 07, 2009 8:40 AM
> To: fusion-dev at lists.osgeo.org
> Subject: RE: [fusion-dev] fusion and projection support
> 
> The default projection of mgMapOL is set to "EPSG:4326" on line 14636
> in
> Openlayers.js. If Proj4js is available the initialisation of the OL
> projection with the followinge statements (around line 10855)
> 
>   if (window.Proj4js) {
>       this.proj = new Proj4js.Proj(projCode);
>   }
> 
> results in this.proj being defined - and finally this leads to my map
> being
> screwed up (wrong scale, extents...) becaus my coords are in another
> CRS
> 
> Andreas
> 
> > -----Original Message-----
> > From: Mike Adair [mailto:madair at dmsolutions.ca]
> > Sent: Tuesday, October 06, 2009 8:09 PM
> > To: Andreas Morf
> > Cc: fusion-dev at lists.osgeo.org
> > Subject: Re: [fusion-dev] fusion and projection support
> >
> > That change is required so that the Measure widget can work with maps
> > in
> > various projections, otherwise the distances measured don't make
> sense
> > at all (for both MapServer and MapGuide).
> >
> > I don't see how that revision would break a MapGuide application,
> > perhaps you can explain?
> >
> > I am working on a patch for MapGuide side of things to set the
> > projection automatically. Ideally the MapGuide API would have a way
> of
> > returning the EPSG code for a map and indeed it does have
> > $csFactory->ConvertWktToEpsgCode($srs), however I am getting an error
> > whenever I try to use that "Could not convert to EPSG code from WKT".
> > It
> > is for this reason that I put support for that in the Map extension
> > element in AppDef. If you can point to a better way of informing the
> > client about the EPSG code for the map I would be happy to hear it.
> >
> > Mike
> >
> >
> >
> > Andreas Morf wrote:
> > >
> > > With rev. 1907 Mike added projection support to fusion - this
> screwed
> > > up my fusion app where I use projected coordinates (swiss grid):
> the
> > > oMapOL was set to default value EPSG:4326 which was the source of
> > > malfunction.
> > >
> > > I normally set the CRS in my MG-mapdefinition and I don't want to
> set
> > > it again in fusion and additionally provide a EPSGxy.js ().
> Shouldn't
> > > fusion read out CRS-def from MG-server mapdef for the actual map
> and
> > > use that for client-side calculations?
> > >
> > > IMHO 1907 looks a bit like a quick and dirty fix for mapserver
> > > concerns - the whole matter shoud be discussed an planned from
> ground
> > > up (RFC?).
> > >
> > > Greets, Andreas
> > >
> > > -------------------------------------------------------------------
> --
> > ---
> > >
> > > _______________________________________________
> > > fusion-dev mailing list
> > > fusion-dev at lists.osgeo.org
> > > http://lists.osgeo.org/mailman/listinfo/fusion-dev
> > >
> >
> > --
> >    Michael Adair
> >    Senior Software Architect
> >    DM Solutions Group Inc.
> >
> >    Office: (613) 565-5056 x26
> >    madair at dmsolutions.ca
> >    http://www.dmsolutions.ca
> >    http://research.dmsolutions.ca
> 
> 
> _______________________________________________
> fusion-dev mailing list
> fusion-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/fusion-dev