[OpenLayers-Users] Question on using multiple layers in different projections

[Stephen Woodbridge]

Hi all,

I have an OL app setup the is using epsg4326 and everything it fine.
It has a mapserver base layer and a vector overlay with markers and 
another with lines.

I have been asked to add Google as an additional base layer.

So my understanding is that the map object will take on the projection 
of the base layer when you switch between them.

I have few questions:

1. I assume that the vector features are not transformed when the base 
layer is switched? Is this true? Which probably means I need to cycle 
through the features and transform them to the base layers projection 
something like:

map.events.register('changebaselayer', map, function(evt, element) {
     var fromProj = map.getUnit()=='m'?epsg4326:epsg900913;
     for (var i=0, var len=layer.features.length; i<len; i++)
         layer.features[i].geometry.transform(fromProj, 
map.getProjectionObject());
     layer.redraw();
});

2. I have a WKT parser object. It need to reproject the features based 
on the current base layer. Can I change the internalProjection on base 
layer change like:

parser.internalProjection = map.getProjectionObject();

Or do I need to destroy and recreate the parser on each change?

I just trying to thing this all through. I can probably try it, but 
getting some conformation or corrections will great reduce the spinning 
wheels effect :).

Thanks,
   -Steve