Client-server interactions: What happens when you launch and exit the application

Between the moment you press the Run button in LyciaStudio, LyciaDesktop, or LyciaWeb and the moment the application starts executing, a number of processes are executed.

Here is a brief diagram of client-server interaction showing the sequence of processes which occur between the connection dialog and the actual execution of the application.

It includes 5 basic agents:

• client,
• WebServer (currently, Jetty web server),
• FglCommand – an intermediary object, execution manager used to handle the application and its children,
• FglProcess – an intermediary object used to handle a definite qrun,
• qrun.  

There is only one FglCommand in a scheme. However, there can be many FglProcesses created depending on the programs functionality.

One FglProcess is created to launch and manage one qrun. If there are more or less qruns than FglProcesses, runtime execution of your application will be troubled.

Below you can find three figures describing how this scheme is realized in definite situations of the application execution.

The first figure shows the client-server interactions taking place at the application launch:

Commands mentioned above include opening forms, displaying tables, etc.

The second figure shows the client-server interactions taking place when you start a new process from within the application at runtime:

The third figure shows the client-server interactions taking place when you exit the application: