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 catalogue.tasks import refresh_instance
  14 from dvcs import models as dvcs_models
  15
  16
  17 class Image(dvcs_models.Document):
  18     """ An editable chunk of text. Every Book text is divided into chunks. """
  19     REPO_PATH = settings.CATALOGUE_IMAGE_REPO_PATH
  20
  21     image = models.FileField(_('image'), upload_to='catalogue/images')
  22     title = models.CharField(_('title'), max_length=255, blank=True)
  23     slug = models.SlugField(_('slug'), unique=True)
  24     public = models.BooleanField(_('public'), default=True, db_index=True)
  25     project = models.ForeignKey(Project, null=True, blank=True)
  26
  27     # cache
  28     _short_html = models.TextField(null=True, blank=True, editable=False)
  29     _new_publishable = models.NullBooleanField(editable=False)
  30     _published = models.NullBooleanField(editable=False)
  31     _changed = models.NullBooleanField(editable=False)
  32
  33     class Meta:
  34         app_label = 'catalogue'
  35         ordering = ['title']
  36         verbose_name = _('image')
  37         verbose_name_plural = _('images')
  38         permissions = [('can_pubmark_image', 'Can mark images for publishing')]
  39
  40     # Representing
  41     # ============
  42
  43     def __unicode__(self):
  44         return self.title
  45
  46     @models.permalink
  47     def get_absolute_url(self):
  48         return ("catalogue_image", [self.slug])
  49
  50     def correct_about(self):
  51         return ["http://%s%s" % (
  52             Site.objects.get_current().domain,
  53             self.get_absolute_url()
  54             ),
  55             "http://%s%s" % (
  56                 'obrazy.redakcja.wolnelektury.pl',
  57                 self.get_absolute_url()
  58             )]
  59
  60     # State & cache
  61     # =============
  62
  63     def last_published(self):
  64         try:
  65             return self.publish_log.all()[0].timestamp
  66         except IndexError:
  67             return None
  68
  69     def assert_publishable(self):
  70         from librarian.picture import WLPicture
  71         from librarian import NoDublinCore, ParseError, ValidationError
  72
  73         class SelfImageStore(object):
  74             def path(self_, slug, mime_type):
  75                 """Returns own file object. Ignores slug ad mime_type."""
  76                 return open(self.image.path)
  77
  78         publishable = self.publishable()
  79         assert publishable, _("There is no publishable revision")
  80         picture_xml = publishable.materialize()
  81
  82         try:
  83             picture = WLPicture.from_bytes(
  84                     picture_xml.encode('utf-8'),
  85                     image_store=SelfImageStore)
  86         except ParseError, e:
  87             raise AssertionError(_('Invalid XML') + ': ' + str(e))
  88         except NoDublinCore:
  89             raise AssertionError(_('No Dublin Core found.'))
  90         except ValidationError, e:
  91             raise AssertionError(_('Invalid Dublin Core') + ': ' + str(e))
  92
  93         valid_about = self.correct_about()
  94         assert picture.picture_info.about in valid_about, \
  95                 _("rdf:about is not") + " " + valid_about[0]
  96
  97     def publishable_error(self):
  98         try:
  99             return self.assert_publishable()
 100         except AssertionError, e:
 101             return e
 102         else:
 103             return None
 104
 105     def accessible(self, request):
 106         return self.public or request.user.is_authenticated()
 107
 108     def is_new_publishable(self):
 109         change = self.publishable()
 110         if not change:
 111             return False
 112         return not change.publish_log.exists()
 113     new_publishable = cached_in_field('_new_publishable')(is_new_publishable)
 114
 115     def is_published(self):
 116         return self.publish_log.exists()
 117     published = cached_in_field('_published')(is_published)
 118
 119     def is_changed(self):
 120         if self.head is None:
 121             return False
 122         return not self.head.publishable
 123     changed = cached_in_field('_changed')(is_changed)
 124
 125     @cached_in_field('_short_html')
 126     def short_html(self):
 127         return render_to_string(
 128                     'catalogue/image_short.html', {'image': self})
 129
 130     def refresh(self):
 131         """This should be done offline."""
 132         self.short_html
 133         self.single
 134         self.new_publishable
 135         self.published
 136
 137     def touch(self):
 138         update = {
 139             "_changed": self.is_changed(),
 140             "_short_html": None,
 141             "_new_publishable": self.is_new_publishable(),
 142             "_published": self.is_published(),
 143         }
 144         Image.objects.filter(pk=self.pk).update(**update)
 145         refresh_instance(self)
 146
 147     def refresh(self):
 148         """This should be done offline."""
 149         self.changed
 150         self.short_html
 151
 152
 153     # Publishing
 154     # ==========
 155
 156     def publish(self, user):
 157         """Publishes the picture on behalf of a (local) user."""
 158         from base64 import b64encode
 159         import apiclient
 160         from catalogue.signals import post_publish
 161
 162         self.assert_publishable()
 163         change = self.publishable()
 164         picture_xml = change.materialize()
 165         picture_data = open(self.image.path).read()
 166         apiclient.api_call(user, "pictures/", {
 167                 "picture_xml": picture_xml,
 168                 "picture_image_data": b64encode(picture_data),
 169             })
 170         # record the publish
 171         log = self.publish_log.create(user=user, change=change)
 172         post_publish.send(sender=log)