Web-Based Solutions

Using a Web browser for mobile applications presents special challenges for the developer. If the Web application interacts with a database or uses server-side scripting, you must install Microsoft Personal Web Server (PWS) on the client to provide offline functionality. PWS is included with the Windows 98 operating system and can be installed from the Windows 95 and Windows NT Workstation Web sites. Unattended installation of PWS is supported. Applications written for the Windows NT Server built-in Web server, Internet Information Services (IIS) version 4.0, should run unchanged on PWS as long as there are no references to server-specific APIs.

IIS 4.0 is a fully programmable Web server that offers developers the following basic features:

• Active Server Pages

  You can write server-based scripts in Visual Basic, Scripting Edition; Microsoft JScript; or PerlScript.

• ADO

  You can access any OLE DB or ODBC data source through the ADO object model by using any of the Visual Studio tools.

• COM and Microsoft Transaction Server

  You can reference COM components, including those in Microsoft Transaction Server (MTS), part of Windows NT Server, written in a variety of languages by using Visual Studio tools.

• Transactional Web page support

  You can call MTS-supported databases by using ASP scripts.

• Session management

  You can use session-level or user-level variables on the server to store user-specific information.

Client-Side and Server-Side Debugging

By using Visual J++ 6.0 and Visual InterDev 6.0 (included in the Microsoft Visual Studio development system), developers delivering Web-based applications can take advantage of COM components and SQL Server. By including Microsoft FrontPage, the Web-based developer has a consistent and easy-to-use tool set for Rapid Application Development (RAD) that provides both component and site creation ability and content development ability. Visual J++ 6.0 and Visual InterDev 6.0 both support rich server and client-side debugging. By using either tool, a developer can debug from the client-side script through the ASP page and into the COM and MTS components.

Sybase Web-based Solutions

Sybase Adaptive Server Anywhere 6.0 comes with an offline Web server called Sybase PowerDynamo, which includes tools for deploying Web pages to clients. PowerDynamo uses a superset of JScript for building server-side scripts. Database access and data formatting are provided by extensions to JScript.

PowerDynamo provides the basic functionality for developing a Web application and accessing it offline. However:

• Programmers must learn proprietary extensions to JScript for connecting to a database and formatting data.
• PowerDynamo does not support COM components or calls to external programs, which limits application functionality, compatibility, and extensibility.
• Although Sybase Adaptive Server Anywhere 6.0 provides transaction support, developers cannot define a Web page as a single transaction.