Hey Chris and all, 

I am building a multi-generation experiment with multiple contribution stages in each generation. To be more precise, we have a total of 12 participants per group distributed across 4 generations (ergo, 3 per generation). The first generation starts, and each of the 3 participants makes 5 contribution decision. After each contribution decision, the 3 participants have the opportunity to use the chat window to communicate with each other. Only if the 3 participants reach a certain contribution threshold, the second generation starts and the same logic applies until the last generation. 

My initial idea was to create one app per generation, have NUM_ROUNDS = 5, and show only the pages of this app to the generation 1. However, then Waitpages do not work (as 9 participants always wait). Is there the opportunity to skip complete apps for certain participants? If I move participants #4-12 already in the app for the second generation, the app for the first generation should work, doesnt it? 

Live Pages as an alternative are a bit problematic as I want to always skip between contribution phase and chat window...

Thank you for any feedback or help and all my best, 
Aurel

Yes you can have the upcoming generations skip the current app using app_after_this_page. And when a generation finishes, you send them to the end of the app_sequence also using app_after_this_page.

Thank you Chris for your quick reply - I tried: 

class Instructions(Page):
    form_model = 'player'

@staticmethod
def app_after_this_page(player, upcoming_apps):
    print('upcoming_apps is', upcoming_apps)
    if player.id_in_group == 1:
        return "G2"
        
But it does not work - do you have another hint for me? Thank you!

Can you describe in more detail about what is not working?

Nothing is happening, all players still proceed to G1 (instead of player with id 1 proceeding to G2).

What is the output of your print statement? Did player 1 proceed to the page after Instructions? Try double checking the documentation for app_after_this_page.

How can I get the print statement? Sorry for the stupid questions... 

Player 1 also just proceeded to G1 instead of G2.

The output of the print statement is in your console where you started the server.

And is P1 able to proceed through all of G1?

It says: "Warning(title="'app_after_this_page' is defined but not used", id=131, app_name='Instructions')"... Hm, weird... And yes, P1 is able to proceed through all of G1. Do I need to extra trigger the function?

it needs to be indented inside the page class (like every @staticmethod)

Jesus... I just missed to intend it properly. It works now... Sorry.