Hi Chris,

>The COM component sounds more flexible

It is...

>Can you tell me the pros and cons of each?

DataClas 2000 is a currently shipping product...PRO!

DataClas 2000 is completely VFP-based. It is not a COM object so it best for VFP applications where you don't want to worry about the overhead of COM. If you later decide that you want you application ported to the web, you can use Web Connect from West-Wind to leverage all of the business logic coded in your DataClas 2000 business objects.

As proof of its stability and scalability, First PREMIER Bank has a DataClas 2000-based application that is used by over 800 customer service reps and over 100 gigs of data.

DataClas COM is not shipping yet....CON! DataClas COM is currently in the beta testing phase...it'll ship in October.

DataClas COM is a Windows DNA compatible data component that empowers developers to build traditional client/server and web-enabled SQL Server 7 applications in record time. It handles all the “plumbing” of connecting and communicating with SQL Server, allowing you to concentrate on coding business rules.

The architecture of DataClas COM is very simple and operates on a “snap-in” model. At the heart of DataClas COM is the DataClas Client Object . There are 2+n types of objects that are snapped into the client object, the DataClas Server Object (1), the DataClas Data Factory Object (2), and the DataClas Business Rule Objects(+n).

The DataClas Client Object is state-ful and is instantiated in the client (Visual FoxPro form, VB form, ASP page, Cold Fusion page, etc). The client object is the object that you will be interacting with the most. It is responsible for persisting information (parent and child) about the current record accessed. It communicates with the DataClas Server Object to pass and retrieve data. Typically, form controls are bound to the properties of the client object. Methods on the client object are responsible for data operations such as saving, deleting, adding records, as well as locating a specific record and it’s children.

Each client object has a collection of business rule objects. When a record is saved, the client object cycles through the business rule objects which apply business rule logic against the data stored in the client object.

The DataClas Server Object is state-less, snaps into the client object, and is responsible for communicating with SQL Server. It makes the actual calls to specificaly named stored procedures within SQL Server. It is MTS compatible and adheres to the Windows DNA model.

The DataClas Data Factory Object snaps into the client object and is responsible for establishing a connection to SQL Server.

The DataClas Business Rule Objects are where business rules are coded. The language these objects are coded in is completely up to the developer. Each DataClas Client Object can have zero or more (+n) business rule objects snapped-in to validate the current data stored in the client object. Once a business rule object is snapped in, it knows which object it is snapped into. Since each business rule object is a self-contained object, you can code one business rule object in Visual FoxPro and another in Visual Basic, it doesn't matter.

One feature of the DataClas Business Rule Objects is that they are highly reusable. For example, suppose there are Student and Instructor tables in a database. They both contain the LastName, FirstName, City, State, and ZipCode fields. Furthermore, one of the business rules states that those fields can not be empty. Since a business rule object knows which object it is currently snapped into, a single business rule object could be coded to check the fields in the client object for an empty value. It wouldn’t matter if the business rule object is snapped into the Student client object or the Instructor client object, it would work either way....very slick.

There will be more information about DataClas COM available on the TakeNote site early next week.

Any more questions about DataClas COM anybody?