apps/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.tasks import refresh_instance
  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
  25     # cache
  26     _short_html = models.TextField(null=True, blank=True, editable=False)
  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 __unicode__(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
  54     # State & cache
  55     # =============
  56
  57     def last_published(self):
  58         try:
  59             return self.publish_log.all()[0].timestamp
  60         except IndexError:
  61             return None
  62
  63     def assert_publishable(self):
  64         from librarian.picture import WLPicture
  65         from librarian import NoDublinCore, ParseError, ValidationError
  66
  67         class SelfImageStore(object):
  68             def path(self_, slug, mime_type):
  69                 """Returns own file object. Ignores slug ad mime_type."""
  70                 return open(self.image.path)
  71
  72         publishable = self.publishable()
  73         assert publishable, _("There is no publishable revision")
  74         picture_xml = publishable.materialize()
  75
  76         try:
  77             picture = WLPicture.from_string(picture_xml.encode('utf-8'),
  78                     image_store=SelfImageStore)
  79         except ParseError, e:
  80             raise AssertionError(_('Invalid XML') + ': ' + str(e))
  81         except NoDublinCore:
  82             raise AssertionError(_('No Dublin Core found.'))
  83         except ValidationError, e:
  84             raise AssertionError(_('Invalid Dublin Core') + ': ' + str(e))
  85
  86         valid_about = self.correct_about()
  87         assert picture.picture_info.about == valid_about, \
  88                 _("rdf:about is not") + " " + valid_about
  89
  90     def publishable_error(self):
  91         try:
  92             return self.assert_publishable()
  93         except AssertionError, e:
  94             return e
  95         else:
  96             return None
  97
  98     def accessible(self, request):
  99         return self.public or request.user.is_authenticated()
 100
 101     def is_new_publishable(self):
 102         change = self.publishable()
 103         if not change:
 104             return False
 105         return not change.publish_log.exists()
 106     new_publishable = cached_in_field('_new_publishable')(is_new_publishable)
 107
 108     def is_published(self):
 109         return self.publish_log.exists()
 110     published = cached_in_field('_published')(is_published)
 111
 112     def is_changed(self):
 113         if self.head is None:
 114             return False
 115         return not self.head.publishable
 116     changed = cached_in_field('_changed')(is_changed)
 117
 118     @cached_in_field('_short_html')
 119     def short_html(self):
 120         return render_to_string(
 121                     'catalogue/image_short.html', {'image': self})
 122
 123     def refresh(self):
 124         """This should be done offline."""
 125         self.short_html
 126         self.single
 127         self.new_publishable
 128         self.published
 129
 130     def touch(self):
 131         update = {
 132             "_changed": self.is_changed(),
 133             "_short_html": None,
 134             "_new_publishable": self.is_new_publishable(),
 135             "_published": self.is_published(),
 136         }
 137         Image.objects.filter(pk=self.pk).update(**update)
 138         refresh_instance(self)
 139
 140     def refresh(self):
 141         """This should be done offline."""
 142         self.changed
 143         self.short_html
 144
 145
 146     # Publishing
 147     # ==========
 148
 149     def publish(self, user):
 150         """Publishes the picture on behalf of a (local) user."""
 151         from base64 import b64encode
 152         import apiclient
 153         from catalogue.signals import post_publish
 154
 155         self.assert_publishable()
 156         change = self.publishable()
 157         picture_xml = change.materialize()
 158         picture_data = open(self.image.path).read()
 159         apiclient.api_call(user, "pictures/", {
 160                 "picture_xml": picture_xml,
 161                 "picture_image_data": b64encode(picture_data),
 162             })
 163         # record the publish
 164         log = self.publish_log.create(user=user, change=change)
 165         post_publish.send(sender=log)