No subject

perspective how it will affect the mapfile configuration and the
mapscript API. Will it
change the API in a logical or rather a constrainted manner?
And how much amount of code should be changed to implement this feature?

> > Theoretically I would write a builtin support for caching features
> > from any of the
> > providers but i would not want to implement a new provider eg.
> > MS_FEATURECACHE_PROVIDER along with MS_OGR or the others. This problem
> > requires to extend the functionality of an existing provider not to
> > write a new one.
>
> I'm afraid I didn't understand this.

Well I have just mentioned that I could not imagne the suggested
solution easily.
But now, I would consider a solution providing to specify one or more
layer being contained
by another layer. This nested approach could be implemented for the
mapfile configuration
and the mapscript API as well like:

LAYER
  CONNECTIONTYPE CUSTOM_LAYER
  ...
  LAYER
    CONNETIONTYPE OGR
    ...
  END
  LAYER
    CONNECTIONTYPE POSTGIS
  END
END

I'm considering this solution is different from my proposal, and would
require to change a similar
amount of the existing code. This approach would give a solution for
different problems
(like implementing provider independent joins for example). Recall
that originally I would like
to add functionality to and existing provider. I can see a slight
analogue to the difference between
the inheritance and the containment from the OO terminology.

>
> I'm not sure why binding the work into the core mapserver code is
> more effective.  When I spoke of Mapscript, I was meaning a case
> where mapscript is used explicitly for drawing the features.  So
> a mapscript loop can query the features from the layer, and then render
> each with appropriate per-feature draw calls.  In this "mapscript owns
> the rendering loop" approach any arbitrary transformation can be
> applied.
>

Do you mean creating an inline layer and feeding the features into it
on the fly?
How can the implementor provide the reusability and the configurability of
the implementation if needed?


Best Regards,

Tamas