Where can I place a code in app’s program, which will be executed just once?

[Tim Wessman]

To have the initialized on app load, you'll want to put code in the application "Start".

VIEW "Start",START()

Note that this will be executed on every application load - if the user starts the app programmatically, switches to another then back, etc. If you need to avoid it for certain circumstances, maybe combining with part 2 below would be helpful.

For the second, I'd probably recommend an app program global variable that you can set and then check in your VIEW code. This would be a variable in your app scope, but not exported to help avoid it being messed with. It would be set when compiling/installing the app for the first time.

<...program file start...>

DiasableView1:=0;

VIEW "Plot",START()
BEGIN
if(DisableView1) then ...
else ... end
END;

That might work to accomplish what you are thinking.