+ def update_can_sell_mp3(self):
+ ret = True
+ for child in self.get_children():
+ child.update_can_sell_mp3()
+ if not child.can_sell_mp3:
+ ret = False
+ if self.has_mp3_file():
+ audio_items = requests.get(f'https://audio.wolnelektury.pl/archive/book/{self.slug}.json').json()['items']
+ if not all(x['project']['can_sell'] for x in audio_items):
+ ret = False
+ self.can_sell_mp3 = ret
+ self.save(update_fields=['can_sell_mp3'])
+