Implementation of GETFLDSTATE and SETFLDSTATE

[Irwin1985]

Implements GETFLDSTATE() and SETFLDSTATE(). State is tracked per workarea using an internal dictionary. Both functions also use _AreaFromParam().

They were marked as Partial since automatic state updates on REPLACE/APPEND require cursor buffering (CURSORSETPROP), which is not yet supported.

Closes Peter Stephan feedback item: GETFLDSTATE / SETFLDSTATE.

[RobertvanderHulst]

Irwin,
The workareas (datasession) class has a mechanism to add data to a workarea/cursor.
There is a cargo dictionary for this. The key is the area number and the value is an object..
This was added for the XPP dialect that has functions for that.
The workareas class has a method SetCargo(dwNum, oObject) an GetCargo(dwNum) to set and get the object
When a workarea is closed, then the cargo slot for that area is cleared.
You could also use the same slot for the field information that you are storing.
Finally the IRdd interface has a FieldIndex method that you can use to lookup the field number for a fieldname. That is MUCH faster than looping through all the fields what you are doing now in _FieldNumFromName(). The implementation in the Workarea class uses a case insensitive dictionary for this. And for tables in a DBC both the short and long name are stored in this dictionary.

[RobertvanderHulst]

One more thing: if you want we can also add a bitarray field to the RDD where we store which field numbers were updated. That would be fairly easy to do.

[Irwin1985]

Robert,

Thanks for the tips, I've applied both suggestions. Regarding the BitArray in the RDD, that sound like a good plan for the next step.