catalogue/publish.py

   1 # -*- coding: utf-8
   2 from django.core.files.base import ContentFile
   3 from django.core.files import File
   4 from django.core.urlresolvers import reverse
   5 from librarian import DocProvider, IOFile
   6 from librarian.pyhtml import EduModuleFormat
   7 from librarian.pypdf import EduModulePDFFormat
   8 from .models import Lesson, Attachment
   9 from fnpdjango.utils.text.slughifi import slughifi
  10
  11
  12 # TODO: Using sorl.thumbnail for now,
  13 # but this should be done in Librarian,
  14 # directly using convert or PIL as a fallback.
  15 def get_image(src_img_path, width=None,
  16         default_width=1600, formats=('PNG', 'JPEG', 'GIF')):
  17     """ Returns an object with `url` and `storage` attributes,
  18         or None if using the original image is OK.
  19     """
  20
  21     from PIL import Image
  22     from sorl.thumbnail import get_thumbnail
  23
  24     # Does it need converting?
  25     # Yes, if width is given explicitly.
  26     convert = width is not None
  27     if not convert:
  28         # Looks like it doesn't need converting.
  29         # But let's try opening it and checking its type.
  30         try:
  31             simg = Image.open(src_img_path)
  32         except IOError:
  33             # It doesn't look like image,
  34             # but maybe it's convertable to one.
  35             convert = True
  36         else:
  37             if simg.format not in formats:
  38                 # It's an image, but it's in some weird format.
  39                 convert = True
  40                 width = simg.size[0]
  41
  42     if convert:
  43         if width is None:
  44             width = default_width
  45         return get_thumbnail(src_img_path, '%sx%s' % (width, 10*width))
  46     else:
  47         return None
  48
  49
  50 class HtmlFormat(EduModuleFormat):
  51     IMAGE_FORMATS = ('PNG', 'JPEG', 'GIF')
  52     DEFAULT_IMAGE_WIDTH = 1600
  53
  54     def find_attachment(self, slug, fmt):
  55         lesson_slug = self.wldoc.book_info.url.slug
  56         try:
  57             # If already saved, use it.
  58             att = Attachment.objects.get(lesson__slug=lesson_slug,
  59                                          slug=slug, ext=fmt)
  60         except Attachment.DoesNotExist, e:
  61             # If attached to source IOFile, save now.
  62             att_name = "%s.%s" % (slug, fmt)
  63             try:
  64                 att_file = self.wldoc.source.attachments[att_name]
  65             except KeyError:
  66                 print u"ATTACHMENT MISSING:", att_name
  67                 raise self.MaterialNotFound()
  68             else:
  69                 lesson = Lesson.objects.get(slug=lesson_slug)
  70                 att = lesson.attachment_set.create(slug=slug, ext=fmt)
  71                 att.file.save(att_name, File(att_file.get_file()))
  72                 return att
  73         else:
  74             return att
  75
  76     def url_for_material(self, slug, fmt):
  77         return self.find_attachment(slug, fmt).file.url
  78
  79     def url_for_image(self, slug, fmt, width=None):
  80         try:
  81             src_img = self.find_attachment(slug, fmt).file
  82         except self.MaterialNotFound:
  83             return ''
  84         img = get_image(src_img.path, width,
  85             self.DEFAULT_IMAGE_WIDTH, self.IMAGE_FORMATS)
  86         return (img or src_img).url
  87
  88     def text_to_anchor(self, text):
  89         return slughifi(text)
  90
  91     def get_forma_url(self, forma):
  92         return '%s#%s' % (
  93             reverse('catalogue_lesson', args=['metody']),
  94             self.text_to_anchor(forma)
  95         )
  96
  97     def get_help_url(self, naglowek):
  98         return '%s%s#%s' % (
  99             '//edukacjamedialna.edu.pl',
 100             reverse('info', args=['jak-korzystac/']),
 101             self.naglowek_to_anchor(naglowek)
 102         )
 103
 104
 105 class PdfFormat(EduModulePDFFormat):
 106     IMAGE_FORMATS = ('PNG', 'JPEG', 'GIF')
 107     DEFAULT_IMAGE_WIDTH = 1600
 108
 109     def get_image(self, name):
 110         src_img = super(PdfFormat, self).get_image(name)
 111         img = get_image(src_img.get_filename(),
 112                 default_width=self.DEFAULT_IMAGE_WIDTH,
 113                 formats=self.IMAGE_FORMATS
 114             )
 115         if img:
 116             return IOFile.from_filename(img.storage.path(img))
 117         else:
 118             return src_img
 119
 120
 121 class OrmDocProvider(DocProvider):
 122     def by_slug(self, slug):
 123         """Should return a file-like object with a WL document XML."""
 124         return IOFile.from_filename(Lesson.objects.get(slug=slug).xml_file.path)