AW: [rap-dev] RAP Architecture and Communication

["Frank Appel" <fappel@xxxxxxxxxxxxxx>]

Hi,

I'm not quite sure what you mean by 'main action' but as RAP uses events for user-interaction I guess you mean where and how for example the button-click will be executed on server-side. This happens in the process action phase of the request lifecycle. The method that is used to trigger all listeners added to a widget is Event#processEvent(). You can use the call hierarchy to investigate where this method gets called. Note that despite the fact I just mentioned the method gets often called in the read data phase. But never the less the actual execution is deferred to the process action phase.

You are guessing correctly, the javascript is calculated on the server and sent to browser as response. At the client site there is a javascript application running, that executes the javascript stream. This application is build on top of the Qooxdoo library and controls the communication between client and server. User input is traced and if an event occurs that needs to inform/invoke the server the application sends a request in way that is understandable for the RAP lifecycle. First all widget state is applied and after that the event processing takes place. Last but not least the render-phase writes the javascript that represents the changes that take place in the action phase.

The kind of magic you are looking for in the render-phase is done in the JSWriter. For example take a look at line 214 of JSWriter. The set method does nothing if the property value hasn't changed. So only the changed values are sent to the client.

AJAX is simply used for the asynchronous request handling, that means that we do not have to replace the whole document as in earlier days of web-developement (This reduces both network-traffic and server-load).

Ciao
Frank 

-----Ursprüngliche Nachricht-----
Von: rap-dev-bounces@xxxxxxxxxxx [mailto:rap-dev-bounces@xxxxxxxxxxx] Im Auftrag von abo@xxxxxxxxxxxxx
Gesendet: Freitag, 14. September 2007 17:01
An: rap-dev@xxxxxxxxxxx
Betreff: [rap-dev] RAP Architecture and Communication



Hi,

I still try to understand the rendering phases in RAP.
What I really can´t figure out is, where in the source-code the main action takes place.
I understand how the different widgets work, together with their LCAs, but i don´t get the point on the communication between client and server.

What happens, if a client accesses a RAP-Application? I believe, the JavaScript is calculated on the server and then sent to the client, on the client, qooxdoo manages the rendering of the widgets.
Now, if some component changes its state ( so it has differences to its preserved state) , the so called "Deltas" are sent to the client and the client has only to render the values which have changed, right?
But as I read the code, it seemed to me, that all the JavaScript Code is sent to the Client everytime something changes.

So I would be very thankful, if someone could give me a short-guide to the code, especially some classes where I can find:

where the communication happens, especially the "Deltas".
Where does AJAX come into play? I must admit, i don´t know Ajax very well, so where is this handled?

Thank you for your effort

Martin


_______________________________________________
rap-dev mailing list
rap-dev@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/rap-dev