The Steps in an Interaction between Web Browser and Server

It is - especially when debugging web applications - very useful to have a reasonable good understanding of the sequence of events that takes place from the time that a web browser submits a request to get a new web page, to the time it receives it.  We can think of this as a Web Interaction.

In this section, we go through the steps that occur, and we look at the subset of these steps you have to develop to get a working Websydian application.

Websydian Application Steps

The steps from a user request to a Websydian application to the display of the response in a web browser is depicted in the figure below.

The steps are the following:

1. The web browser user takes some action.
2. The Web Browser submits the corresponding HTTP request.
3. The Web Server Software routes the request to the server of the Websydian application.
4. The Web Application Server decodes the request.
5. The Web Application Server processes the request.
6. The Web Application Server encodes the response as an HTML Web Page.
7. The Web Application Server submits the response to the Web Server Software.
8. The Web Server Software submits the HTTP response to the Web Browser.
9. The Web Browser updates the display.

To build a Web Application without Websydian, you must design, implement, and test steps 4 through 7 (colored red in the above list). 

However, being a Websydian user, you get steps 4, 6, and 7 for free. So:

You only have to do step 5!

And step 5 cannot be built into a standard component, because it is inherently application dependent.  Only the application developer can know what processing is required to produce an appropriate response to a given request.