from otree.api import *


doc = """
Your app description
"""


class Constants(BaseConstants):
    name_in_url = 'intro'
    players_per_group = None
    num_rounds = 1


class Subsession(BaseSubsession):
    pass


class Group(BaseGroup):
    pass


class Player(BasePlayer):
    age = models.IntegerField(label='What is your age?', max=100, min=0)

# PAGES
class introScreening(Page):
    form_model = 'player'
    form_fields = ['age']


class age(Page):
    form_model = 'player'
    @staticmethod
    def is_displayed(player):
        return player.age < 21

class Results(Page):
    pass


page_sequence = [introScreening, age]