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Class to close any cursors created after it was instantiated
Dragan Nedeljkovich, January 31, 2007
Generally, datasessions serve this purpose - they create an isolated environment where our code can run and use tables, cursors etc as it pleases, without disturbing other code. Sometimes wee need a little more granularity - to have a routine which may create any number of cursors, open additional t...
Summary
Generally, datasessions serve this purpose - they create an isolated environment where our code can run and use tables, cursors etc as it pleases, without disturbing other code. Sometimes wee need a little more granularity - to have a routine which may create any number of cursors, open additional tables, and close them all when done, without closing any previously open ones. This simple class will do just that.
Description
The idea is quite simple, and so is the code. Use aUsed() in the beginning, to get a snapshot of what is open, and use once more in the end, to see what's open now - and then close anything that wasn't open in the beginning. To do that, just instantiate this class as a local object. It will get that snapshot when instantiated. When it goes out of scope (i.e. your piece of code exits), in its destroy it will do the cleanup. So all you need is to can save the class in CloseTemp.prg, and in your code 
local oCloser
oCloser=newobject("CloseTemp", "closetemp.prg")
and the class will do the rest. Keep in mind that it will not touch other datasessions. 
Define Class CloseTemp As Custom
	Dimension a1[1]
	nFiles=0

	Procedure Init
		This.nFiles=Aused(atemp)
		If This.nFiles>0
			Acopy(atemp, This.a1)
		Else
			This.a1=""
		Endif

	Procedure Destroy
		For i=1 To Aused(aNow)
			If Ascan(This.a1, aNow[i,1],-1,-1,1,2+4)=0
				Use In aNow[i,1]
			Endif
		Endfor
Enddefine
Dragan Nedeljkovich, Now officially retired
After (and/or along with) playing with Sinclair ZX Spectrum and Atari ST, I left teaching in 1986 and went through a series of machines and operating systems: CP/M (Cobol, Turbo pascal, CB-80 Basic), PDP and VAX (Cobol, Basic Plus 2, scripts), DOS 3.1 through 7.0, Windows 3.1 through XP. Ran several (almost) forgotten networks - RPTI, Lantastic, WFWG, Novell 2.x, 3.x, 4.x, Windows peer-to-peer and eventually NT and just plain IP (Win/Lin mix). After a brief flirt with Clipper in 1988, discovered Fox and went through mFoxplus 2.1 (DOS), Foxplus (Xenix), FP 1.01, 1.02, 2.0, 2.6, VFP 3.0 (briefly), 5.0, 6.0 (SP 1 to 5), 7.0 SP1, 8SP1 and now 9. Maintained one framework, created another (in DOS Fox), helped create yet another one, then used a few more - bought or in-house - frameworks. Always too lazy to type the same sequence more than four times, I'd rather write a builder or some Intellisense. Along the way, promoted a dozen beginners into experienced programmers. IOW, been there, done that, the T-shirts are recycled already, and it's still interesting and fun way to live. Retired in 2019 and finally found time for those pet projects... in Dabo/Python.
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