EnvLib for Visual FoxPro 9

EnvLib is a collection of classes that you can use (and aggregate) to save and restore your environment. The classes save, set, and restore SET, ON, open table, system variable, object properties, and other helpers.

The original version of EnvLib for Visual FoxPro was created by Tom Rettig in July 1995. Tom passed away in February 1996. Since then Visual FoxPro has moved forward significantly. This is an updated version of his original library.

Features

• Over 120 lightweight classes, one for each aspect of the Visual FoxPro environment.
• Objects save, and optionally set, aspects of the VFP environment upon init().
• Objects restore their aspect of the VFP environment upon destroy().
• Therefore facets of the VFP environment are automatically reset when objects go out of scope.
• Objects can be nested at design-time or run-time to group many aspects into one object.
• Objects can be configured at creation-time to not reset upon destroy().

Using EnvLib

To include Envlib in your application, simply call SET PROCEDURE ... ADDITIVE prior to using it.

SET PROCEDURE TO <path>\EnvLib ADDITIVE

Example -- saving the current path

In standard Visual FoxPro, saving and setting SET PATH looks something like this:

LOCAL lcAPath
lcPath= SET( "path" )
SET PATH TO newPath  && or SET PATH TO newPath ADDITIVE

* Lots of code here

* Now restore the previously selected work area
SET PATH TO &lcPath   && Do this everywhere you might exit
RETURN

With Envlib, you do this:

LOCAL loAlias  
loAlias= CREATEOBJECT( "SetPath", "newPath" )
* or loAlias= CREATEOBJECT( "SetPath", "newPath", "Additive" )

* Lots of code here

RETURN

Note you don't need to cover every exit point because when lcPath goes out of lexical scope, SET PATH is reset upon its destroy.

Example -- saving the current work area

In standard Visual FoxPro, saving the current work area looks something like this:

LOCAL lcAlias
lcAlias= SELECT()

* Lots of code here

* Now restore the previously selected work area
SELECT ( lcAlias )   && Do this everywhere you might exit
RETURN

With Envlib, you do this:

LOCAL loAlias  
loAlias= CREATEOBJECT( "SaveSelect" )

* Lots of code here

RETURN

Note you don't need to cover every exit point because when loAlias goes out of lexical scope, the work area is reset upon its destroy.

Example -- saving the current work area and setting a new work area

LOCAL lcAlias
lcAlias= SELECT()
SELECT Customer

* Lots of code here

* Now restore the previously selected work area
SELECT ( lcAlias )   && Do this everywhere you might exit
RETURN

With Envlib, you do this:

LOCAL loAlias  
loAlias= CREATEOBJECT( "SetSelect". "Customer" )

* Lots of code here

RETURN

Classes in EnvLib

Abstract Classes

Class	Parent	Notes
Set	Custom	Abstract class
SetTwo	Set	Abstract class
SetOnOff	Set	Abstract class
SetOnOffTwo	SetTwo	Abstract class
On	Custom	Abstract class
SaveArea	Custom	Abstract class
SaveUsedArea	SaveArea	Abstract class

SET Classes

These classes save, set, and restore the various VFP SET commands that have corresponding SET() functions.

Class	Parent
SetAlternate	SetOnOffTwo
SetAnsi	SetOnOff
SetAsserts	SetOnOff
SetAutoIncError	SetOnOff
SetAutosave	SetOnOff
SetBell	SetOnOff
SetBlocksize	Set
SetBrstatus	SetOnOff
SetCarry	SetOnOff
SetCentury	SetOnOff
SetClassLib	Set
SetClear	SetOnOff
SetClock	SetOnOff
SetCollate	Set
SetCoverage	Set
SetColor	Set
SetCompatible	SetOnOffTwo
SetConfirm	SetOnOff
SetConsole	SetOnOff
SetCpcompile	Set
SetCpdialog	SetOnOff
SetCurrency	SetTwo
SetCursor	SetOnOff
SetDatabase	Set
SetDataSession	Set
SetDate	Set
SetDebug	SetOnOff
SetDecimals	Set
SetDefault	Set
SetDeleted	SetOnOff
SetDelimiters	SetOnOffTwo
SetDevelopment	SetOnOff
SetDisplay	Set
SetDohistory	SetOnOff
SetEcho	SetOnOff
SetEngineBehavior	Set
SetEscape	SetOnOff
SetExact	SetOnOff
SetExclusive	SetOnOff
SetFdow	Set
SetFixed	SetOnOff
SetFullPath	SetOnOff
SetFweek	Set
SetHeadings	SetOnOff
SetHelp	SetOnOffTwo
SetHelpfilter	Set
SetHours	Set
SetIntensity	SetOnOff
SetKeycomp	Set
SetLibrary	Set
SetLock	SetOnOff
SetLogErrors	SetOnOff
SetMargin	Set
SetMackey	Set
SetMark	Set
SetMemoWidth	Set
SetMessage	SetTwo
SetMultiLocks	SetOnOff
SetNear	SetOnOff
SetNotify	SetOnOff
SetNull	SetOnOff
SetNullDisplay	Set
SetOdometer	Set
SetOLEObject	SetOnOff
SetOptimize	SetOnOff
SetPalette	SetOnOff
SetPath	Set
SetPrinter	SetOnOffTwo
SetPoint	Set
SetProcedure	Set
SetReadBorder	SetOnOff
SetRefresh	SetTwo
SetReprocess	Set
SetResource	SetOnOffTwo
SetResourceCreate	SetResource
SetSafety	SetOnOff
SetSeconds	SetOnOff
SetSeparator	Set
SetSpace	SetOnOff
SetStatus	SetOnOff
SetStatusBar	SetOnOff
SetStep	SetOnOff
SetSysFormats	SetOnOff
SetSysMenu	Set
SetTableValidate	Set
SetTalk	SetOnOff
SetTopic	SetTwo
SetTrBetween	SetOnOff
SetTypeahead	Set
SetUdfParms	Set
SetUnique	SetOnOff
SetView	SetOnOff
SetWindowOfMemo	Set
SetVfpDefaults	Custom

ON Classes

These classes save, set, and restore the various VFP ON commands that have corresponding ON() functions.

Class	Parent
OnError	On
OnKey	On
OnKeyLabel	On
OnShutDown	On

Workarea Helper Classes

These classes save, set, and restore the various aspects of saving the properties of work areas.

Class	Parent
SaveSelect	SaveArea
SetSelect	SaveSelect
SaveBuffering	SaveUsedArea
SetBuffering	SaveBuffering
SaveRecno	SaveUsedArea
SaveOrder	SaveUsedArea
SetOrder	SaveOrder
SaveFilter	SaveUsedArea
SetFilter	SaveFilter
SaveRelation	SaveUsedArea
SetRelation	SaveRelation
SaveTable	SaveUsedArea
SaveAllTables	Custom
OpenAliasCheckpoint	Custom

Miscellaneous Helper Classes

These classes save, set, and restore various other things.

Class	Parent	Notes
SaveProperty	Custom
SetProperty	SaveProperty
SetSysVar	Custom
MessageTimer	Timer
SetLockScreen	Custom	Saves and sets form.lockScreen, resetting it when the instance goes out of scope.
ScopeTimer	Custom	Upon destroy() debugout the object's scope lifetime in seconds..