src/catalogue/models/image.py

   1 # This file is part of FNP-Redakcja, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   3 #
   4 from django.conf import settings
   5 from django.contrib.sites.models import Site
   6 from django.db import models
   7 from django.template.loader import render_to_string
   8 from django.utils.translation import ugettext_lazy as _
   9 from catalogue.helpers import cached_in_field
  10 from catalogue.models import Project
  11 from dvcs import models as dvcs_models
  12
  13
  14 class Image(dvcs_models.Document):
  15     """ An editable chunk of text. Every Book text is divided into chunks. """
  16     REPO_PATH = settings.CATALOGUE_IMAGE_REPO_PATH
  17
  18     image = models.FileField(_('image'), upload_to='catalogue/images')
  19     title = models.CharField(_('title'), max_length=255, blank=True)
  20     slug = models.SlugField(_('slug'), unique=True)
  21     public = models.BooleanField(_('public'), default=True, db_index=True)
  22     project = models.ForeignKey(Project, null=True, blank=True)
  23
  24     # cache
  25     _new_publishable = models.NullBooleanField(editable=False)
  26     _published = models.NullBooleanField(editable=False)
  27     _changed = models.NullBooleanField(editable=False)
  28
  29     class Meta:
  30         app_label = 'catalogue'
  31         ordering = ['title']
  32         verbose_name = _('image')
  33         verbose_name_plural = _('images')
  34         permissions = [('can_pubmark_image', 'Can mark images for publishing')]
  35
  36     # Representing
  37     # ============
  38
  39     def __str__(self):
  40         return self.title
  41
  42     @models.permalink
  43     def get_absolute_url(self):
  44         return ("catalogue_image", [self.slug])
  45
  46     def correct_about(self):
  47         return ["http://%s%s" % (
  48             Site.objects.get_current().domain,
  49             self.get_absolute_url()
  50             ),
  51             "http://%s%s" % (
  52                 'obrazy.redakcja.wolnelektury.pl',
  53                 self.get_absolute_url()
  54             )]
  55
  56     # State & cache
  57     # =============
  58
  59     def last_published(self):
  60         try:
  61             return self.publish_log.all()[0].timestamp
  62         except IndexError:
  63             return None
  64
  65     def assert_publishable(self):
  66         from librarian.picture import WLPicture
  67         from librarian import NoDublinCore, ParseError, ValidationError
  68
  69         class SelfImageStore(object):
  70             def path(self_, slug, mime_type):
  71                 """Returns own file object. Ignores slug ad mime_type."""
  72                 return open(self.image.path)
  73
  74         publishable = self.publishable()
  75         assert publishable, _("There is no publishable revision")
  76         picture_xml = publishable.materialize()
  77
  78         try:
  79             picture = WLPicture.from_bytes(
  80                     picture_xml.encode('utf-8'),
  81                     image_store=SelfImageStore)
  82         except ParseError as e:
  83             raise AssertionError(_('Invalid XML') + ': ' + str(e))
  84         except NoDublinCore:
  85             raise AssertionError(_('No Dublin Core found.'))
  86         except ValidationError as e:
  87             raise AssertionError(_('Invalid Dublin Core') + ': ' + str(e))
  88
  89         valid_about = self.correct_about()
  90         assert picture.picture_info.about in valid_about, \
  91                 _("rdf:about is not") + " " + valid_about[0]
  92
  93     def publishable_error(self):
  94         try:
  95             return self.assert_publishable()
  96         except AssertionError as e:
  97             return e
  98         else:
  99             return None
 100
 101     def accessible(self, request):
 102         return self.public or request.user.is_authenticated
 103
 104     def is_new_publishable(self):
 105         change = self.publishable()
 106         if not change:
 107             return False
 108         return not change.publish_log.exists()
 109     new_publishable = cached_in_field('_new_publishable')(is_new_publishable)
 110
 111     def is_published(self):
 112         return self.publish_log.exists()
 113     published = cached_in_field('_published')(is_published)
 114
 115     def is_changed(self):
 116         if self.head is None:
 117             return False
 118         return not self.head.publishable
 119     changed = cached_in_field('_changed')(is_changed)
 120
 121     def touch(self):
 122         update = {
 123             "_changed": self.is_changed(),
 124             "_new_publishable": self.is_new_publishable(),
 125             "_published": self.is_published(),
 126         }
 127         Image.objects.filter(pk=self.pk).update(**update)
 128
 129     # Publishing
 130     # ==========
 131
 132     def publish(self, user):
 133         """Publishes the picture on behalf of a (local) user."""
 134         from base64 import b64encode
 135         import apiclient
 136         from catalogue.signals import post_publish
 137
 138         self.assert_publishable()
 139         change = self.publishable()
 140         picture_xml = change.materialize()
 141         picture_data = open(self.image.path).read()
 142         apiclient.api_call(user, "pictures/", {
 143                 "picture_xml": picture_xml,
 144                 "picture_image_data": b64encode(picture_data),
 145             })
 146         # record the publish
 147         log = self.publish_log.create(user=user, change=change)
 148         post_publish.send(sender=log)