Saturday, February 21, 2009

What is CA-Visual Objects ?

CCH : CA-VO aka CA-Visual Objects was Computer Associates attempt to bring CA-Clipper to the Windows World.

BTW, in my quest to move into the Windows world, I actually bought a copy way back in 1995 and attended a 5-day Training by the renowned Clipper Guru, Rick Spence in Kuala Lumpur, Malaysia. That was before I discovered Delphi.

As I understand it, CA-VO development was taken over by GrafX Software Development and the latest version is 2.8 released on 15th May 2007


Clipper Compatibility

Visual Objects features a structured superset of the Clipper Language. While the user interface will need to be redesigned to take advantage of the Windows Graphical User Interface (GUI), most of the core "business logic" used in Clipper applications can be recomplied as-is under Visual Objects.

Visual Objects includes support for Clipper based DBF files including those using the NTX, CDX, and MDX indexing methods via Replaceable Database Driver (RDD) technology.

Xbase Superset

Visual Objects features a structured superset of the Xbase language. (Xbase is the industry standard term for those programming languages that inherit from the original dBASE system, including CA-Clipper, CA-dBFast, the dBASE family of products, and FoxPro.)

The Xbase superset contains extensions for Windows and its environment, including the ability to access all Win32 Application Programming Interface (API) functions for low-level, system programming.

Open Database Access

Visual Objects gives you a wide variety of choices in terms of database access. It supports:
  • Both procedural and object-oriented access to Xbase databases

    Visual Objects supports the procedural database commands and functions—such as SKIP and EOF()—that are traditional to Xbase languages.

    It also includes, however, an object-oriented interface to Xbase database management. The object-oriented interface is akin, semantically and syntactically, to the commands and functions traditionally used in procedural access. Instead of commands like APPEND, COMMIT, and ZAP, for example, you will use methods named Append(), Commit(), and Zap() to perform the same operation.

    Note: With these new methods, all the capabilities of the traditional Xbase approach are provided, but have been enhanced to fit the event-driven, multi-tasking nature of GUI applications.

  • Access to both Xbase and SQL databases

    When using an object-oriented approach to database management, both Xbase and SQL databases can be accessed. Furthermore, access to these two different types of databases is accomplished using a single, compatible protocol. This allows an application to manage Xbase and SQL databases with the same code.

  • Several different Xbase/SQL database formats

    When accessing Xbase databases (using either a procedural or object-oriented approach), you can choose from a variety of file formats. This is accomplished through replaceable database driver (RDD) technology. With RDDs, a single application can access different database file formats using a common language interface. This allows you to tailor your applications so that migrating from one database format to another is simple and straightforward.

    Visual Objects supplies several popular RDDs, and through its open architecture allows for development of third-party RDDs. See the Replaceable Database Drivers section in the “Using DBF Files” chapter in the Programmer’s Guide for more information about RDD technology. Refer to the “RDD Specifics” appendix in the same volume for detailed information about specific RDDs.

    Similarly, support for SQL databases is accomplished using Open Database Connectivity (ODBC), a widely used API for SQL access under Windows. This technology also uses replaceable drivers, supplied as dynamic link libraries (DLLs), which standardize the interface to the various database formats. Visual Objects comes bundled with DLLs for many of the popular ODBC formats, and provides language support for a superset of the standard ODBC API, as well as, an object-oriented interface compatible with that used for Xbase database files.

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Welcome to Clipper... Clipper... Clipper

In 1997, then using Delphi 3, I had already created 32-bits Windows applications for HRIS, ERP and CRM. In 2007, using Ruby on Rails, an AJAX powered CRM site running on Apache & MySQL was created and I am now using Visual Studio .Net 2008 to create web-based projects and Delphi 7 for Win32 applications using SQL2005 & DBFCDX.

So, why then am I reviving the Original Clipper... Clipper... Clipper via a Blog as CA-Clipper is a programming language for the DOS world ? Believe it or not, there are still some clients using my mission-critical CA-Clipper applications for DOS installed in the late 80's and up to the mid 90's. This is testimony to CA-Clipper's robustness as a language :-)

With the widespread introduction of Windows 7 64-bits as the standard O/S for new Windows based PCs & Notebooks, CA-Clipper EXE simply will not work and it has become imperative for Clipper programmers to migrate immediately to Harbour to build 32/64 bits EXEs

Since 28th January 2009, this blog has been read by 134,389 (10/3/11 - 39,277) unique visitors (of which 45,151 (10/3/11 - 13,929) are returning visitors) from 103 countries and 1,574 cities & towns in Europe (37; 764 cities), North America (3; 373 cities) , Central America & Caribeans (6; 13 cities), South America(10; 226 cities), Africa & Middle-East (12; 44 cities) , Asia-Pacific (21; 175 cities). So, obviously Clipper is Alive & Well : -)

TIA & Enjoy ! (10th October 2012, 11:05; 13th November 2015)

Original Welcome Page for Clipper... Clipper... Clipper

This is the original Welcome Page for Clipper... Clipper... Clipper, which I am republishing for historical and sentimental reasons. The only changes that I have made was to fix all the broken links. BTW, the counter from is still working :-)

Welcome to Chee Chong Hwa's Malaysian WWW web site which is dedicated to Clipperheads throughout the world.

This site started out as a teeny-weeny section of Who the heck is Chee Chong Hwa ? and has graduated into a full blown web site of more than 140 pages (actually hundreds of A4 size pages) ! This is due to its growing popularity and tremendous encouragements from visiting Clipperheads from 100 countries worldwide, from North America, Central America, Caribbean, South America, Europe, Middle-East, Africa and Asia-Pacific. Thanx Clipperheads, you all made this happen !

What is Clipper ?

You may ask, what is this Clipper stuff ? Could Clipper be something to do with sailing as it is the name of a very fast sailing American ship in the 19th century ?

Well, Clipper or to be precise, CA-Clipper is the premier PC-Software development tool for DOS. It was first developed by Nantucket Corporation initially as a compiler for dBase3+ programs. Since then, CA-Clipper has evolved away from its x-base roots with the introduction of lexical scoping & pre-defined objects like TBrowse. As at today, the most stable version ofClipper is 5.2e while the latest version, 5.3a was introduced on 21 May 1996.

As at 11th November, 1996, an unofficial 5.3a fixes file was made available by Jo French. See the About CA-Clipper 5.3a section for more details. BTW, Jo French uploaded the revised 5.3a fixes file on 20th November, 1996.

Latest News

The latest news is that CA has finally released the long-awaited 5.3b patch on 21 May, 1997.

For 5.3b users, you must a take a look at Jo French's comments on unfixed bugs in 5.3b.

BTW, have you used Click ? If you're a serious Clipperprogrammer and need an excellent code formatter, Click is a natural choice. How to get it ? Simple, access Phil Barnett's site via my Cool Clipper Sites.

32-bits Clipper for Windows ?

Have you tried Xbase ++ ? Well, I have and compared to Delphi (my current Windows programming tool of choice), I'm still sticking to Delphi.

Anyway, you should visit the Alaska Home Page. Give it a chance and then draw your own conclusions !.

The Harbour Project

Is this the future of Xbase ? Take a look at at the Harbour Project

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