Of course, not every application client uses a Web browser for the client:
Many applications involve substantial client-side functionality. For this
reason, VB 5.0 includes two new controls to enable developers to extend their
applications to include Internet technologies. The Internet Transfer Control
simplifies the use of the two most common Internet protocols: HTTP for
retrieving HTML pages and FTP for working with files. The Winsock control
provides a convenient encapsulation of the underlying Windows Sockets library,
which you can use for any socket-based activity, such as sending mail (Simple
Mail Transfer Protocol--SMTP) and retrieving news (Network News Transfer
Protocol--NNTP).
Data Access
The data access changes in VB 5.0 are evolutionary rather than
revolutionary. The trend in data access with VB is toward large-scale enterprise
development, with a particular focus on ODBC. For this reason, the most
significant feature in the updated version of the Data Access Objects (DAO) that
ships with VB 5.0 is ODBCDirect, which provides access to ODBC data sources
through DAO without loading the Jet engine. ODBCDirect lets developers use one
object library for both enterprise and local and workgroup data.
The Enterprise Edition's RDO 2.0 is an update to the thin object layer on
top of the ODBC API that first shipped with VB 4.0. RDO 2.0 offers many new
features, such as events and enhanced control over cursors, and it executes
substantially faster in many cases than RDO 1.0. Another data access mechanism
to consider is ActiveX Data Objects (ADO), which ships with Internet Information
Server (IIS) 3.0 and works with OLE DB providers. So far, Microsoft has released
OLE DB providers for SQL Server and generic ODBC, but other OLE DB providers
will be coming soon.
The Enterprise Edition also includes Microsoft's new Visual Database Tools.
These tools run as an add-in to the VB 5.0 IDE. Visual Database Tools include
the following components:
* Data View: A graphical tool for creating, viewing, and editing database
objects.
* Database Designer: A tool for creating and modifying Microsoft SQL Server
database objects including Tables, relationships, indexes, and constraints. This
tool also lets you generate and edit Transact-SQL (T-SQL) change scripts.
* Query Designer: A graphical tool for constructing and executing ODBC
queries. This tool also generates SQL and lets you edit, browse, and view live
data.
* Source Code Editor: A tool for creating, editing, and executing stored
procedures and triggers in SQL Server and Oracle databases.
Enterprise Development
For several years now, VB has been one of the most commonly used tools for
corporate data access. Thanks to RDO, VB successfully competes with data-centric
tools, such as PowerBuilder, for traditional client/server development. Scaling
traditional client/server applications up to the enterprise level--where
developers must distribute an application across a number of machines--has not
been an easy task. To operate at this level, developers need to break out
business processing and data access code from both the client and the server and
run them in a separate, intermediate layer. This layer must scale across
machines to meet substantial throughput requirements. Microsoft's tool for
managing this intermediate layer is MTS, which centralizes handling
configuration, security, object queuing, connection management, thread pooling,
and object synchronization. Bundling SQL Server and MTS with the Enterprise
Edition gives VB developers all the components necessary to do true
enterprise-level development.
Of course, managing a large-scale development process is not trivial.
Microsoft has recognized this and developed Microsoft Repository for managing
the many components that comprise a complex software system. The first version
of Repository ships as an add-in to VB 5.0, and although it's not yet as
polished and complete as Visual SourceSafe, this enterprise tool shows the
direction Microsoft is heading.
Another important feature of the Enterprise Edition is Microsoft Visual
Modeler, a subset of Rational Software's Rose/Visual Basic tool. Visual Modeler
lets developers create class diagrams for a system, generate the corresponding
definition code, and regenerate class diagrams when the underlying code changes
during development. Visual Modeler wasn't ready when Microsoft released VB 5.0
to manufacturing, so registered owners must download it from
http://www.microsoft.com/vstudio/owner/default.asp.
Be More Productive
VB 5.0 is a major advance over the previous version in a number of key
areas. First, it's significantly faster, even if you don't use native code.
Second, the new IDE can make developers significantly more productive. Finally,
VB 5.0 has capabilities, such as the ability to create ActiveX controls, that
are not yet available with any other high-level development tool. VB 5.0's only
flaw is its complexity: A new developer can easily be overwhelmed by the
available options. Fortunately, Microsoft offers versions for different
development environments and levels of expertise. Developers using VB 5.0 can
specialize in those areas--front-end desktop development, business rule
processing, and data access-- that best use their skills.