[fdo-internals] Dropping off PSC
dmorissette at mapgears.com
Wed Nov 3 10:45:58 EDT 2010
Traian Stanev wrote:
>> I got one idea. What about implementing MapInfo Provider without any
>> touch on OGR API?
> Wouldn't that then be a universal OGR API provider? Or do you mean that you will dynamic_cast the OGRLayer to something from the mitab headers and use specific mitab functionality?
I think what he meant was to go through the MITAB C++ classes instead of
through the generic OGR classes, and keep all extensions in the MITAB
classes instead of trying to extend the OGR classes.
For instance, MITAB implements a TABFeature which is derived from
OGRFeature and handles MapInfo-specific stuff, and then special classes
such as TABPoint, TABRegion, etc. are derived from TABFeature. When used
from OGR these are all OGRFeature's, but when used through the MITAB API
they give you access to all the MapInfo specific stuff.
... and to answer Leaf's question: Yes, I think it would be
easier/simpler to keep all MapInfo specific stuff in MITAB classes, and
to base the FDO provider directly on the MITAB classes instead of on the
generic OGR classes. It is exactly for that purpose that we maintain
MITAB as a separate library (i.e. there are other vendors who use it
this way as well).
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