IT 101: Data Flow

This series of articles is a compilation of the notes I gathered during my programming bootcamp at Green Fox Academy, last year.

You can read the other articles here:

1. Endpoints
2. Authentication

Layers

If think about the responsibilities of a web application, we notice that a web application has the following concerns:

• It needs to process the user’s input and return the correct response back to the user
• It needs an exception handling mechanism that provides reasonable error messages to the user
• It needs a transaction management strategy
• It needs to handle both authentication and authorization
• It needs to implement the business logic of the application
• It needs to communicate with the used data storage and other external resources

We can fulfil all these concerns by using only three layers. These layers are:

• The web layer is the uppermost layer of a web application. It is responsible of processing user’s input and returning the correct response back to the user. The web layer must also handle the exceptions thrown by the other layers. Because the web layer is the entry point of our application, it must take care of authentication and act as a first line of defense against unauthorized users.
• The service layer resides below the web layer. It acts as a…