src/catalogue/models/image.py

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