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Visual FoxPro is a data-centric object-oriented and procedural programming language produced by Microsoft. It is derived from FoxPro (originally known as FoxBASE) which was developed by Fox Software beginning in 1984. Fox Technologies merged with Microsoft in 1992 and the software acquired further features and the prefix "Visual". The last version of FoxPro (2.6) worked under Mac OS, DOS, Windows, and Unix: Visual FoxPro 3.0, the first "Visual" version, dropped the platform support to only Mac and Windows, and later versions were Windows-only. The current version of Visual FoxPro is COM-based and Microsoft has stated that they do not intend to create a Microsoft .NET version.
FoxPro originated as a member of the class of languages commonly referred to as "xBase" languages, which have syntax based on the dBase programming language. Other members of the xBase language family include Clipper and Recital. (A history of the early years of xBase can be found in the dBASE entry.) Visual FoxPro, commonly abbreviated as VFP, is tightly integrated with its own relational database engine, which extends FoxPro's xBase capabilities to support SQL query and data manipulation. Unlike most database management systems, Visual FoxPro is a full-featured, dynamic programming language that does not require the use of an additional general-purpose programming environment. It can be used to write not just traditional "fat client" applications, but also middleware and web applications. Recent History In late 2002, some community members demonstrated that Visual FoxPro can run on Linux under the Wine Windows compatibility suite. In 2003, this led to complaints by Microsoft: it was claimed that the deployment of runtime FoxPro code on non-Windows machines violates the End User License Agreement. Rumors suggesting that Microsoft intends to end support for FoxPro have been common since Microsoft's acquisition of the product, despite the product having one of the longest support timeframes for a Microsoft product (extended support until 2015). In March 2007, Microsoft announced "that there will be no VFP 10", thus making VFP9 (released to manufacturing on December 17, 2004) the last commercial VFP release from Microsoft. The support of Version 9 is ongoing with a service pack that was released December 8, 2005. At the time of the end of life announcement, work on the next release codenamed Sedna which was built on top of the VFP9 codebase had already begun. Sedna consisted mainly of Xbase components to support a number of interoperability scenarios with various Microsoft technologies including SQL Server 2005, .NET, WinFX, Windows Vista, and Office 12. Microsoft plans to release these components as community releases via the CodePlex site. On March 1, 2006, Microsoft released a Community Technology Preview (CTP) of Sedna. According to the Fox team, the current plan "for releasing Service Pack 2 for VFP 9.0 will be some time in 2007, at the same time or near the same time of the release of Sedna". The most recent release of Sedna CTP and SP2 Beta was in June 2007. In December 2005, VFP broke into the top 20 on TIOBE's Programming Community Index for the first time. In March 2007 it is at position 19, making it a "B" language. As of August 7, 2007 it dropped into position 22. On March 13 2007 Microsoft stated that it will not be releasing its Visual FoxPro development software past version 9.0. Microsoft will continue to support the Visual FoxPro core until 2015 with standard support through January 2010 and extended support through January 2015 via the developer tools life-cycle support plan. Meanwhile, some of the FoxPro-related technology can be seen in other Microsoft products such as SQL Server, Team Foundation Server and various portions of the .Net Framework. In late March 2007 a grassroots campaign was started by the Spanish-speaking FoxPro community at MasFoxPro (MoreFoxPro in English) to sign a petition to Microsoft to continue updating Visual FoxPro or release it to the community as Open Source. On April 3, 2007 the movement was noted by the technical press. Also on April 3, 2007 Microsoft responded to the petitioner's requests with this statement from Alan Griver: "We're very aware of the FoxPro community and that played a large part in what we announced on March 13th. It's never an easy decision to announce that we're not going to release another version of a product and it's one that we consider very carefully. "We're not announcing the end of FoxPro: Obviously, FoxPro applications will continue to work. By some of our internal estimates, there are more applications running in FoxPro 2.6 than there are in VFP and FoxPro 2.6 hasn't been supported in many years. Visual FoxPro 9 will be supported by Microsoft through 2015. "For Microsoft to continue to evolve the FoxPro base, we would need to look at creating a 64-bit development environment and that would involve an almost complete rewrite of the core product. We've also invested in creating a scalable database with SQL Server, including the freely available SQL Server Express Edition. As far as forming a partnership with a third-party is concerned, we've heard from a number of large FoxPro customers that this would make it impossible for them to continue to use FoxPro since it would no longer be from an approved vendor. We felt that putting the environment into open source on CodePlex, which balances the needs of both the community and the large customers, was the best path forward." Version information Operating system compatibility Supported Windows VersionsVersion VFP 3.0 VFP 5.0 VFP 6.0 VFP 7.0 VFP 8.0 VFP 9.0 Windows 3.x Yes No No No No No Windows NT 4.0 Yes Yes Yes Yes No [6] No [7] Windows 95 Yes Yes Yes Runtime only No [8] No Windows 98 Yes Yes Yes Yes Runtime only Runtime only Windows ME Yes Yes Yes Yes Runtime only Runtime only Windows 2000 Yes Yes Yes Yes Yes Yes Windows XP Yes Yes Yes Yes Yes Yes Windows 2003 ? ? Yes Yes Yes Yes Windows Vista ? See Note[9] Yes Yes Yes Yes Information on Executable FilesVersion VERSION() returns EXE Size EXE Date DLL Size DLL Name VFP 9 Visual FoxPro 09.00.0000.2412 for Windows 5,620 kb 13-DEC-2004 4,600 kb VFP9R.DLL VFP 8 Visual FoxPro 08.00.0000.3117 for Windows 5,236 kb 25-SEP-2003 4,200 kb VFP8R.DLL VFP 7 Visual FoxPro 07.00.0000.9465 for Windows 4,260 kb 04-JAN-2002 3,344 kb VFP7R.DLL VFP 6 Visual FoxPro 06.00.8961.00 for Windows 4,091 kb 18-AUG-2000 3,295 kb VFP6R.DLL VFP 5 Visual FoxPro 5.0.0.415 for Windows 4,065 kb 24-JAN-1997 3,148 kb VFP500.DLL VFP 3 Visual FoxPro 03.00.00.0711 for Windows 4,374 kb 16-DEC-1995 3,657 kb VFP300.ESL FPW 2.6a FoxPro 2.6a for Windows 2,444 kb 28-SEP-1994 n/a n/a Code samples Hello World example: MESSAGEBOX("Hello World") Object loForm = CREATEOBJECT("HiForm") loForm.Show(1) DEFINE CLASS HiForm AS Form AutoCenter = .T. Caption = "Hello, World" ADD OBJECT lblHi as Label WITH ; Caption = "Hello, World!" ENDDEFINE loMine = CREATEOBJECT("MyClass") ? loMine.cProp1 && This will work. (Double-ampersand marks an end-of-line comment) ? loMine.cProp2 && Program Error: Property CPROP2 is not found. ? loMine.MyMethod1() && This will work. ? loMine.MyMethod2() && Program Error: Property MYMETHOD2 is not found. DEFINE CLASS MyClass AS Custom cProp1 = "My Property" && This is a public property HIDDEN cProp2 && This is a private (hidden) property PROCEDURE Init() && Class constructor This.cProp2 = "This is a hidden property." ENDPROC PROCEDURE MyMethod1() * This is a public method, calling a hidden method that returns * the value of a hidden property. RETURN This.MyMethod2() ENDPROC HIDDEN PROCEDURE MyMethod2() && This is a private (hidden) method RETURN This.cProp2 ENDPROC ENDDEFINE Data handling * Create a table CREATE TABLE randData (iData I) * Populate with random data using xBase and SQL DML commands FOR i = 1 TO 50 APPEND BLANK REPLACE iData WITH (RAND() * 100) INSERT INTO randData (iData) VALUES (RAND() * 100) ENDFOR * Place a structural index on the data INDEX ON iData TAG iData CLOSE ALL * Display sorted data using xBase-style commands USE randData SET ORDER TO iData GO TOP LIST NEXT 10 && First 10 SKIP 81 LIST NEXT 10 && Last 10 CLOSE ALL * Browse sorted data using SQL DML commands SELECT * ; FROM randData ; ORDER BY iData DESCENDING ODBC Access using SQL Passthrough * Connect to an ODBC data source LOCAL nHnd nHnd = SQLCONNECT ("ODBCDSN", "user", "pwd") * Execute a SQL ccommand LOCAL nResult nResult = SQLEXEC (nHnd, "USE master") IF nResult < 0 MESSAGEBOX ("MASTER database does not exist!") RETURN ENDIF * Retrieve data from the remote server and stores it in * a local data cursor nResult = SQLEXEC (nHnd, "SELECT * FROM authors", "QAUTHORS") * Update a record in a remote table using parameters LOCAL cAuthorID, cAuthorName cAuthorID = "1001" cAuthorName = "New name" nResult = SQLEXEC (nHnd,"UPDATE authors SET auth_name = ?cAuthorName WHERE auth_id = ?cAuthorID") * Close the connection SQLDISCONNECT(nHnd) Beta code names VFP 3 - Taz VFP 5 - RoadRunner VFP 6 - Tahoe VFP 7 - Sedona VFP 8 - Toledo VFP 9 - Europa VFP Next - Sedna Pancho - (pancho@alezar.ru) |
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| Methane Releases From Arctic Shelf May Be Much Larger and Faster Than Anticipated
A section of the Arctic Ocean seafloor that holds vast stores of frozen methane is showing signs of instability and widespread venting of the powerful greenhouse gas, according to the findings of an international research team led by University of Alaska Fairbanks scientists Natalia Shakhova and Igor Semiletov. The research results, published in the March 5 edition of the journal Science, show that the permafrost under the East Siberian Arctic Shelf, long thought to be an impermeable ...
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