The LA Fox Developer Newsletter

August 1997

Save the Environment

By Arnon Gal-Oz

VFP (and FP2.x before it) gives the developer a lot of control

over the environment at run time. This includes commands that

lets you set basic things like what century we are in (SET

CENTURY TO), different sethngs related to localization (e.g.

SET DATE TO or SET CURRENCY TO), stuff that affect

searching and string matching (like SET ANSI, SET COLLATE),

and stuff that affects the way VFP works in general (like SET

MULTI LOCKS, SET EXCLUSIVE).

It is very worthwhile for any beginner VFP developer to check

the SET section of the VFP help file to find what all these

commands can do for you. While I am at it, another section of

the help file worth reading is the SYSO section, there are many

functions there that otherwise are not part of the language,

which lets you do some interesting stuff. While this does not fall

under the subject of this article I’ll just mention 2 or 3 interesting

SYS functions. For example sys(3O54) lets you see the optimi-

zation level of your SELECT statements, SYS(1270) will give

you a reference to the object under the mouse or at a specific X/

Y, and SYS(2333) is needed when you want to use an OCX

created in VB5.

Now returning to our business, many of the different SETtings

will not change throughout the application, and indeed a lot of

FP2.x programs started with a bunch of SET commands in the

main program like SET TALK OFF, SET EXCLUSiVE OFF etc.

One of the new concepts added in VFP is the private

datasession, this brings a lot of good and saves some program-

ming effort. For example it is now very easy to have the same

form open twice each time with a different record, in earlier

versions you had to do some programming to make this hap-

pen. However this prevents you from using the same technique

described above of setting all your SETs in the main program.

Because many of the SET commands are scoped to the

datasession, they are reset to default values for each instance

of a form and have to be set manually. The table below lists the

SET commands that are scoped to the datasession:

ANSI

BLOCKSIZE

CENTURY

CONFIRM

DATABASE

CARRY

COLLATE

CURRENCY

DATE

DELETED

DECIMALS

EXCLUSIVE

FIXED

LOCK

MEMOWDTH

EXACT

HOURS

MULTILOCKS

NULL

REPROCESS

NEAR

POINT

TALK

SAFETY

AUTOSAVE

SECONDS

SYSFORMATS

UNIQUE

Note that to set them to the value you want before any table is

loaded, you have to set them in the BeforeOpenTables event of

the DataEnvironment. If you don’t use a DataEnvironemnt, or

(Con’t, page 4)

Special Big Announcement

The LA Fox Developer's Group has entered into an agree-

ment with Macmillan Computer Publishing. LA Fox mem-

bers can now purchase all Macmillan Computer Publishing

titles at a discount of 30% off retail pricing.

Macmillan owns the following publishers:

Que

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Macmillan Technical Publishing

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To take advantage of this offer, you must be a member-in-good-

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can receive our special account number and the 800 access

number by calling me at 800/499-6237 or 714/375-3300, ore-

mailing me at CompuServe (72723,3422) or brlee@earthlink.net.

On-Line Updates

The online update document for Mastering Visual FoxPro is now

available. This document, designed to be used with the Master-

ing Visual FoxPro CD-ROM-based training product, covers the

new features and differences between Visual FoxPro 3.0 and

Visual FoxPro 5.0. Now you can use the advanced features of

the Visual FoxPro Web site to quickly explore the contents of

this useful learning tool and shorten your learning curve for

Visual FoxPro 5.0! This document is also available for download

at http://www.microsoft.com/vfoxpro/.

Appendix Added to Update Document - Micro Endeavors

Appendix. Microsoft has added the comprehensive Micro

Endeavors Appendix of FoxPro vs. Visual FoxPro language

changes to the Mastering Visual FoxPro CD Update Document.

Also available for download at http://www.microsoft.com/vfoxpro/

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