Southwest Fox 2011

October 26-29, 2011
SanTan Elegante Conference & Reception Center/Legado Hotel
Gilbert, AZ

Executing VFP Code in Silverlight Applications

Presenter: Uwe Habermann

Level: Intermediate

Create Internet applications with the most modern user interface and do the programming work in VFP_ Zes, it is possible! It|s easz to create COM servers with VFP. And, it|s easz to use COM servers in Visual Studio projects. But what about a Silverlight client application, which runs in the browser of an Internet client_ Method calls from the Silverlight client side can be forwarded to the server side bz using a domain service. The return value is delivered to the Silverlight front/end. This allows running anz code for business logic at the server side. Additionallz, we will discuss how the architecture of a COM server can be set up, so that code changes do not require re/registering the COM server.Zou will learn>  How to create VFP COM servers How to use VFP COM servers from Visual Studio server projects How to call COM server methods from a Silverlight frontend How to change code without changing or re/registering the COM server

Prerequisites: None

Using VFP Databases in Silverlight Applications

Presenter: Uwe Habermann

Level: Intermediate

Silverlight applications are supposed to work with SQL Server databases. However, it is possible to access other databases as well. Now, when we have access to COM server methods, it's possible to do almost everything we can do in VFP - even to access a VFP database, to read and save data, and to provide this functionality to a modern Silverlight application. However, doing so requires some knowledge about how data are handled in Silverlight applications. C# data classes are needed and data must be transferred over the Internet by a domain service. The final step is presenting and editing these data in the user interface.

You will learn:

How to use VFP COM servers from Visual Studio server projects
How to create C# data classes
How to create a domain service
How to receive and present data in Silverlight applications
How to send data to the COM server side

Prerequisites: COM server basics and the Executing VFP code in Silverlight Applications session.

Data Access Techniques Using CursorAdapters

Presenter: Venelina Jordanova

Level: Beginner

With the CursorAdapter class, VFP programmers have a powerful object, which renders data from the data source into a Visual FoxPro cursor. Using the CursorAdapter class, the developer can access various data sources in one well-known and handy way, plus it's easy to switch between different database platforms. Processing data is one of the main purposes of the information systems that we develop today. Often, in our applications, we need to access not only native VFP tables, but also other data sources like SQL Server, MySQL, Oracle and so forth. The VFP CursorAdapter class is an excellent resource that helps us to accomplish this. Even better, we can develop portable applications accessing different database platforms.

Whether developing on-shelf applications, or migrating the database of in-house applications, the CursorAdapter class helps the developer to build applications that can be upsized without rewriting the data access. This session will demonstrate how to use CursorAdapter objects to access mixed data sources as well as how to develop easy-to-upsize data access. We will discuss the properties and methods of the CursorAdapter class and how to use them for better control over data retrieval and updates.

You will learn:

The basics of the CursorAdapter class
How to use CursorAdapter classes for data access.
How to use CursorAdapter classes to switch at run-time between different data sources
Why CursorAdapters are better than views

Prerequisites: None

Improve Data Access with CursorAdapters

Presenter: Venelina Jordanova

Level: Intermediate

The CursorAdapter class has been in VFP since version 8.0 but it's still neglected. Whether connecting data sources or using the class to apply business rules to data, it is a great tool to dig deep into data, with all the power of object oriented programming.

This session will not discuss the CursorAdapter class' basics. The focus is on refinements, and tips and tricks in its usage. The session will demonstrate advanced approaches in data retrieval using parameterized queries, with ideas for how to handle special cases, such as needing more than 256 fields in a cursor, sending updates when querying more than one table in the Select command, and even using stored procedures for retrieving and updating data.

Additionally, we will discuss different data access drivers, their advantages and disadvantages, as well as specifics of several database engines, and ways to debug the commands sent to the database. Retrieving values generated at the server side after inserting and updating are also an important part of database access and the session will reveal these specifics.

Last but not least, in a professional application must pay attention to error processing. The CursorAdapter class provides events to help make that better.

You will learn:

How to control data access
How to control inserting and updating data in tables
How to handle update conflicts
How to handle errors

Prerequisites: CursorAdapter class basics