[Mapbender-dev] OpenLayers integration

[Christoph Baudson]

In order to allow to use OpenLayers instead of the Mapbender map
"mapframe1", I have done some refactoring in a branch.

This is the idea:

Currently, the maps and the service data are always loaded in map.php
(even if no map is contained in the application). I have isolated the code
concerning maps and service data, and have added these files as "modules"
to mapframe1.

If you were to add a map module like "OpenLayers", you would just replace
"mapframe1", and everything should work as usual. We just need to add
"OLON"  (OpenLayers Object Notation, basically the OpenLayers map
serialized as JSON) as a new output format to the map and service classes.

Of course, the old controls will not work with an OpenLayers map frame. We
should update the "requires" fields for modules (like almost all buttons
that do map manipulation, like "zoomIn1" etc), and check if the
application violates any of these constraints.

I will start to add the OLON output functions to the map and service
classes as soon as there is some funding; I'll be starting with
class_map.php and class_wms.php. We should have basic functionality very
soon, after the development has been funded.

Christoph