Limitations in Win32 Clients
of the Windows Distributed Internet Architecture, we started to see Web sites that
allowed simple transactions to occur. Clients on browsers could access Web sites that had
COM components available to them that allowed them to retrieve information from the
database. So now we gained the capability to simulate the environment of the Win32
platform. The client software the browser can access information on a server. But as
with the Win32 environment, we are limited in the way in which the information is
presented to us. Customization is neither widespread nor broadly developed.
Let us look into limitations of these technologies.
In a client-server environment visual tool such as Visual Basic, are often used to create a
rich user interface. The drawbacks is that such client software is difficult to deploy and
maintain, requiring and install on every client and a change to every client when an
upgrade is needed.
DLL conflicts on the client are frequent because of variations in the version of the
operating system and other software installed on the client.
Visual Basic is the most common language used to write middle-tier components. This
requires high level of expertise in COM. Since these middle-tire components are
implemented using Microsoft Transaction Server on Windows NT or COM+ services on
Windows 2000. These components use stateless designs, which can look very different
from the stateful designs often used in client-based components.
COM components, in the middle tier must work together, Versioning all the components
properly so that they understand each other's interfaces can be a challenge. This requires
a highly sophisticated skill level and a well - controlled deployment process.
COM works well on Microsoft platforms. But it suffers from lack of interoperability with
other platforms. One of the most important ways functionality can be reused is for a
software component to inherit another component, But COM does not support
inheritance.
Visual Basic is the most popular language for developing applications with the DNA
model, this is used in two major roles - forms based VB Clients and COM components.
This VB6 language has its own limitations it doesn't have the capability of
multithreading, lack of OOPS concepts, Poor error handling ability and poor integration