B2B Integration : A Practical Guide to Collaborative E-commerce

Integration Patterns 71
presentation, content, business logic and integration makes site
maintenance and updates relatively easy.
Vertical portals have much in common as far as functionality and
connectivity issues required to build dynamic user interfaces are
concerned. The framework should provide all the common features as
an out-of-the-box solution, leaving the other uncommon features such
as business logic and visual design — which are unique to each
company and each vertical portal. It must, however, provide a platform
to facilitate rapid, value-added development of these features, including
the presentation layer. Companies can use generic templates of user
interfaces as the starting point, rather than developing the whole code
from scratch.
The data presented by portals comes from several heterogeneous
sources that include legacy, relational, packaged and partner data sources.
Thus the portal framework has to provide connectivity or integration
with enterprise applications. In fact, portals are built on top of EAI
platforms.
Presentation layer
The presentation layer is responsible for providing a user-friendly frontend
interface to users. Through this layer, users view and interact with
the data. A very basic example of the presentation layer is an HTMLbased
front-end of any Website. Java Server Pages (JSPs), Active
Server Pages (ASPs), VBScript, JavaScript, Java Applets, ActiveX,
Dynamic HTML, Cascade Style Sheets (CSS), WML and cHTML are
some of the other presentation technologies. A front-end may be built
using one or a combination of these technologies. In some cases, the
interface can even be a custom developed application in Visual Basic
(VB), Visual C++, or Java that runs on the user machines as a standalone
application. However, this will not be the case with a true Web
portal application.
Services layer
The services layer provides foundation infrastructure on which portals
are built. This layer resides between the presentation and the connectivity