src/api/fields.py

   1 # This file is part of Wolne Lektury, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Wolne Lektury. See NOTICE for more information.
   3 #
   4 from rest_framework import serializers
   5 from sorl.thumbnail import default
   6 from django.urls import reverse
   7 from club.models import Membership
   8
   9
  10 class AbsoluteURLField(serializers.ReadOnlyField):
  11     def __init__(self, view_name=None, view_args=None, source='get_absolute_url', *args, **kwargs):
  12         if view_name is not None:
  13             source = '*'
  14         super(AbsoluteURLField, self).__init__(*args, source=source, **kwargs)
  15         self.view_name = view_name
  16         self.view_args = {}
  17         if view_args:
  18             for v in view_args:
  19                 fields = v.split(':', 1)
  20                 self.view_args[fields[0]] = fields[1] if len(fields) > 1 else fields[0]
  21
  22     def to_representation(self, value):
  23         if self.view_name is not None:
  24             kwargs = {
  25                 arg: getattr(value, field)
  26                 for (arg, field) in self.view_args.items()
  27             }
  28             value = reverse(self.view_name, kwargs=kwargs)
  29         return self.context['request'].build_absolute_uri(value)
  30
  31
  32 class LegacyMixin:
  33     def to_representation(self, value):
  34         value = super(LegacyMixin, self).to_representation(value)
  35         non_null_fields = getattr(getattr(self, 'Meta', None), 'legacy_non_null_fields', [])
  36         for field in non_null_fields:
  37             if field in value and value[field] is None:
  38                 value[field] = ''
  39         return value
  40
  41
  42 class UserPremiumField(serializers.ReadOnlyField):
  43     def __init__(self, *args, **kwargs):
  44         super(UserPremiumField, self).__init__(*args, source='*', **kwargs)
  45
  46     def to_representation(self, value):
  47         return Membership.is_active_for(value)
  48
  49
  50 class ThumbnailField(serializers.FileField):
  51     def __init__(self, geometry, *args, **kwargs):
  52         self.geometry = geometry
  53         super(ThumbnailField, self).__init__(*args, **kwargs)
  54
  55     def to_representation(self, value):
  56         if value:
  57             return super(ThumbnailField, self).to_representation(
  58                 default.backend.get_thumbnail(value, self.geometry)
  59             )