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Set standards for Web development with N-Tier methodologies

The lack of development standards can make deciphering an application written by another Web developer a trying task. Find out how N-Tier development methodologies can help lend clarity to your development by breaking the functional design into layers.

Editor’s note: This article originally appeared in TechRepublic’s Web Development Zone TechMail. Subscribe, and you’ll receive information on Web-development related projects and trends.

During the past 10 years, I have consulted with many companies and have found that there is an alarming lack of Web development standards. The result of this lack of standards is usually chaos. The biggest problems occur when new programmers or consultants try to decipher what the original Web application writers were trying to accomplish.

For example, I recently worked on an ASP page that was written by at least three different developers. It was more than 3,000 lines long and included three different database access methods. The C++ objects returned each field as a separate property, the VB objects used ADO, and there was inline ADO code that called stored procedures. All used ODBC to connect to the database.

It took a full week to make sense out of the process flow.

I prefer using N-Tier development methodologies when creating Internet applications by breaking the functional design into separate layers (the data access layer, the business rules layer, and the presentation layer) and defining the process flow of the application using object-oriented analysis, design, and modeling techniques. In this article, I’ll show you some simple ways to use N-Tier methods to lend clarity to your development work.

Component-Based Scalable Architecture (CSLA) for multiple user interface back-end code
Once the business and data objects have been implemented, a new application can quickly be constructed by developing the desired user interface. For example, once an application has been built using a Visual Basic user interface, a browser-based user interface can be constructed that works with the same business and data tiers. Any COM-compliant development tool, VB, ASP, C++, Java, Delphi, etc., can be used to build the presentation layer.

Because of CSLA, the user interface and business tiers are insulated from changes in the data tier. The result is that an application may be deployed based on one database—MS Access, for example—and later switched to another database platform, like SQL Server or Oracle, with few if any changes to the code that's required for the UI and business layers.

Additionally, since ADO is used whenever possible in the data services tier, a change in database often means minimal code changes in the data services tier, as well.

For the presentation layer, I prefer to create a set of standard style sheets that define the overall look and feel of your site. This makes changing fonts and colors as easy as possible. Following the Object-Oriented methodology, all pages inherit their style settings from one place.

For more information
For HTML standards, follow the W3.org specifications. To make sure your HTML documents conform to W3C HTML and XHTML recommendations, you can use the W3C HTML Validation Service to check them.
For additional information, check out these links: The Web Standards Project HTML Bad Style Page


 
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