Development Patterns: 3 Layers Web Software Development

Hi,

How is it going? =)

Today I'll begin to discuss with all you about Development Patterns. This is very important to all programmers.The first one is 3-Layers. So, go on..

Development in 3 Layers in Computing means to separate the system logically in 3 independents layers. They are:

-> Data Access Layer
-> Business Logic Layer
-> User Interface

Data Access Layer is responsible to communicate with data physical storage and to abstract them in a structure to make it able to be used by others layers.

Business Logic Layer contains the intelligent area from the system. It manipulates all the information provided from the Data Access Layer, it makes and invokes actions and provide information to be shown in the layer above.

User Interface is the layer that shows the informations to the users e receive their actions.

Object-Oriented Programming makes it ables to be made easily and this development type is becoming stronger because OO owns all the sources needed by its.

The advantage of this type of development is that, with layer independence, changes can be made without big impacts in all the system. You can change all your data storage, do migration between different Data Bases, provide data via WebServices, etc... without change any other part of others layers. Or add others functionalities in your system without stay worried with the Data Access, even though change all your interface, ... without stay worried about any other layer.

But, nothing is perfect, this development type also brings some disadvantages. Object transition between layers is not the better way to earn performance and to work with development in different layers can become hard. But, there are a lot of ways to reduce both.

Web Development Technologies delayed to give needed support to this type of development. But, the new age of development looks like to have borned to this.

All FrameWork Asp.Net Languages (C#, VB.net, J#) were developed (or adapted) to Object-Oriented Development. And Jsp (Java Server Pages) inherits OO from Java, the first one of the OO modern languages. Php also is in this wave with the version 5, with a great Objected-Oriented Support.

In my view, Web Applications have a lot of advantages to earn with this type of development. More the Desktop Application.

Next post we will discuss about MVC Development Pattern.

See Yah'' =)