MS RFC: Layer Plug-in Architecture

[Jani Averbach]

> Stephen Woodbridge wrote Thursday, September 08, 2005 11:32 AM
> 
> Would it make sense to treat change layer type like a create/clone
> new layer followed by a delete old layer. 

I think this usage pattern isn't the problem, I think you can't do this 
at the moment.  

For example if you first create a POSTGIS layer and then just
change _it_ to RASTER, you will leak db connections.  But if you first
copy this existing POSTGIS layer, and change the copy then it should
work because the original still exists and will close/release whatever
resources it is holding.

> Then the implementation would be equivalent to the first
> problem. When you create the new layer all the information is cloned
> from the existing layer and the connection type is set up
> appropriately for the changes requested followed by the delete.


Can we ensure for all MapScript languages that if you copy a layer,
everything is copied over, except vtable which is set to NULL on the
copy?

If we can do/ensure that then the whole problem is solved and handled
by first problem.

BR, Jani

-- 
Jani Averbach