from otree.api import * doc = """Detect and block mobile browsers""" class Constants(BaseConstants): name_in_url = 'detect_mobile' players_per_group = None num_rounds = 1 class Subsession(BaseSubsession): pass class Group(BaseGroup): pass class Player(BasePlayer): is_mobile = models.BooleanField() # PAGES class MobileCheck(Page): form_model = 'player' form_fields = ['is_mobile'] def error_message(player: Player, values): if values['is_mobile']: return "Sorry, this experiment does not allow mobile browsers." class Task(Page): pass page_sequence = [MobileCheck, Task]