pretty book descriptions and don't hide short descriptions

[wolnelektury.git] / apps / catalogue / views.py

diff --git a/apps/catalogue/views.py b/apps/catalogue/views.py
index de72b04..47abe63 100644 (file)
--- a/apps/catalogue/views.py
+++ b/apps/catalogue/views.py
@@ -8,6 +8,8 @@ import sys
 import pprint
 import traceback
 import re
 import pprint
 import traceback
 import re

+import itertools
+from operator import itemgetter

 
 from django.conf import settings
 from django.template import RequestContext
 
 from django.conf import settings
 from django.template import RequestContext


@@ -26,6 +28,7 @@ from django.utils.encoding import force_unicode
 from django.utils.http import urlquote_plus
 from django.views.decorators import cache
 from django.utils.translation import ugettext as _
 from django.utils.http import urlquote_plus
 from django.views.decorators import cache
 from django.utils.translation import ugettext as _

+from django.views.generic.list_detail import object_list

 
 from catalogue import models
 from catalogue import forms
 
 from catalogue import models
 from catalogue import forms


@@ -43,7 +46,7 @@ class LazyEncoder(simplejson.JSONEncoder):
         return obj
 
 
         return obj
 
 

-def main_page(request):    
+def main_page(request):

     if request.user.is_authenticated():
         shelves = models.Tag.objects.filter(category='set', user=request.user)
         new_set_form = forms.NewSetForm()
     if request.user.is_authenticated():
         shelves = models.Tag.objects.filter(category='set', user=request.user)
         new_set_form = forms.NewSetForm()


@@ -52,7 +55,7 @@ def main_page(request):
     fragment_tags = models.Tag.objects.usage_for_model(models.Fragment, counts=True,
         extra={'where': ["catalogue_tag.category = 'theme'"] + [extra_where]})
     categories = split_tags(tags)
     fragment_tags = models.Tag.objects.usage_for_model(models.Fragment, counts=True,
         extra={'where': ["catalogue_tag.category = 'theme'"] + [extra_where]})
     categories = split_tags(tags)

-    
+

     form = forms.SearchForm()
     return render_to_response('catalogue/main_page.html', locals(),
         context_instance=RequestContext(request))
     form = forms.SearchForm()
     return render_to_response('catalogue/main_page.html', locals(),
         context_instance=RequestContext(request))


@@ -61,100 +64,128 @@ def main_page(request):
 def book_list(request):
     books = models.Book.objects.all()
     form = forms.SearchForm()
 def book_list(request):
     books = models.Book.objects.all()
     form = forms.SearchForm()

-    
+

     books_by_first_letter = SortedDict()
     for book in books:
         books_by_first_letter.setdefault(book.title[0], []).append(book)
     books_by_first_letter = SortedDict()
     for book in books:
         books_by_first_letter.setdefault(book.title[0], []).append(book)

-    
+

     return render_to_response('catalogue/book_list.html', locals(),
         context_instance=RequestContext(request))
 
 
     return render_to_response('catalogue/book_list.html', locals(),
         context_instance=RequestContext(request))
 
 

+def differentiate_tags(request, tags, ambiguous_slugs):
+    beginning = '/'.join(tag.url_chunk for tag in tags)
+    unparsed = '/'.join(ambiguous_slugs[1:])
+    options = []
+    for tag in models.Tag.objects.exclude(category='book').filter(slug=ambiguous_slugs[0]):
+        options.append({
+            'url_args': '/'.join((beginning, tag.url_chunk, unparsed)).strip('/'),
+            'tags': [tag]
+        })
+    return render_to_response('catalogue/differentiate_tags.html',
+                {'tags': tags, 'options': options, 'unparsed': ambiguous_slugs[1:]},
+                context_instance=RequestContext(request))
+
+

 def tagged_object_list(request, tags=''):
 def tagged_object_list(request, tags=''):

-    # Prevent DoS attacks on our database
-    if len(tags.split('/')) > 6:
-        raise Http404
-        

     try:
         tags = models.Tag.get_tag_list(tags)
     except models.Tag.DoesNotExist:
         raise Http404
     try:
         tags = models.Tag.get_tag_list(tags)
     except models.Tag.DoesNotExist:
         raise Http404

-    
+    except models.Tag.MultipleObjectsReturned, e:
+        return differentiate_tags(request, e.tags, e.ambiguous_slugs)
+
+    try:
+        if len(tags) > settings.MAX_TAG_LIST:
+            raise Http404
+    except AttributeError:
+        pass
+

     if len([tag for tag in tags if tag.category == 'book']):
         raise Http404
     if len([tag for tag in tags if tag.category == 'book']):
         raise Http404

-    
+

     theme_is_set = [tag for tag in tags if tag.category == 'theme']
     shelf_is_set = len(tags) == 1 and tags[0].category == 'set'
     theme_is_set = [tag for tag in tags if tag.category == 'theme']
     shelf_is_set = len(tags) == 1 and tags[0].category == 'set'

-    my_shelf_is_set = shelf_is_set and request.user.is_authenticated() and request.user == shelf[0].user
-    
-    objects = only_author = pd_counter = categories = None
-    
+    my_shelf_is_set = shelf_is_set and request.user.is_authenticated() and request.user == tags[0].user
+
+    objects = only_author = pd_counter = None
+    categories = {}
+

     if theme_is_set:
         shelf_tags = [tag for tag in tags if tag.category == 'set']
         fragment_tags = [tag for tag in tags if tag.category != 'set']
         fragments = models.Fragment.tagged.with_all(fragment_tags)
     if theme_is_set:
         shelf_tags = [tag for tag in tags if tag.category == 'set']
         fragment_tags = [tag for tag in tags if tag.category != 'set']
         fragments = models.Fragment.tagged.with_all(fragment_tags)

-        
+

         if shelf_tags:
         if shelf_tags:

-            books = models.Book.tagged.with_all(shelf_tags)
-            l_tags = [models.Tag.objects.get(slug = 'l-' + book.slug) for book in books]
-            fragments = (fragment for fragment in models.Fragment.tagged.with_any(l_tags) if fragment in fragments)
-        
-        fragment_keys = (fragment.pk for fragment in fragments)
+            books = models.Book.tagged.with_all(shelf_tags).order_by()
+            l_tags = [book.book_tag() for book in books]
+            fragments = models.Fragment.tagged.with_any(l_tags, fragments)
+
+        # newtagging goes crazy if we just try:
+        #related_tags = models.Tag.objects.usage_for_queryset(fragments, counts=True,
+        #                    extra={'where': ["catalogue_tag.category != 'book'"]})
+        fragment_keys = [fragment.pk for fragment in fragments]

         if fragment_keys:
             related_tags = models.Fragment.tags.usage(counts=True,
         if fragment_keys:
             related_tags = models.Fragment.tags.usage(counts=True,

-                                filters={'pk__in': fragment_keys}, 
+                                filters={'pk__in': fragment_keys},

                                 extra={'where': ["catalogue_tag.category != 'book'"]})
             related_tags = (tag for tag in related_tags if tag not in fragment_tags)
             categories = split_tags(related_tags)
                                 extra={'where': ["catalogue_tag.category != 'book'"]})
             related_tags = (tag for tag in related_tags if tag not in fragment_tags)
             categories = split_tags(related_tags)

-            
+

             objects = fragments
     else:
             objects = fragments
     else:

-        books = models.Book.tagged.with_all(tags)
-        l_tags = [models.Tag.objects.get(slug = 'l-' + book.slug) for book in books]
-        book_keys = [book.pk for book in books]
-        if book_keys:
-            related_tags = models.Book.tags.usage(counts=True,
-                                filters={'pk__in': book_keys}, 
-                                extra={'where': ["catalogue_tag.category NOT IN ('set', 'book', 'theme')"]})
-            categories = split_tags(related_tags)
-    
-            fragment_keys = [fragment.pk for fragment in models.Fragment.tagged.with_any(l_tags)]
-            if fragment_keys:
-                categories['theme'] = models.Fragment.tags.usage(counts=True,
-                                    filters={'pk__in': fragment_keys}, 
-                                    extra={'where': ["catalogue_tag.category = 'theme'"]})
-                
-            books = books.exclude(parent__in = book_keys)
-            objects = books
-        
+        # get relevant books and their tags
+        objects = models.Book.tagged.with_all(tags).order_by()
+        l_tags = [book.book_tag() for book in objects]
+        # eliminate descendants
+        descendants_keys = [book.pk for book in models.Book.tagged.with_any(l_tags)]
+        if descendants_keys:
+            objects = objects.exclude(pk__in=descendants_keys)
+
+        # get related tags from `tag_counter` and `theme_counter`
+        related_counts = {}
+        tags_pks = [tag.pk for tag in tags]
+        for book in objects:
+            for tag_pk, value in itertools.chain(book.tag_counter.iteritems(), book.theme_counter.iteritems()):
+                if tag_pk in tags_pks:
+                    continue
+                related_counts[tag_pk] = related_counts.get(tag_pk, 0) + value
+        related_tags = models.Tag.objects.filter(pk__in=related_counts.keys())
+        related_tags = [tag for tag in related_tags if tag not in tags]
+        for tag in related_tags:
+            tag.count = related_counts[tag.pk]
+
+        categories = split_tags(related_tags)
+        del related_tags
+

     if not objects:
         only_author = len(tags) == 1 and tags[0].category == 'author'
         pd_counter = only_author and tags[0].goes_to_pd()
         objects = models.Book.objects.none()
     if not objects:
         only_author = len(tags) == 1 and tags[0].category == 'author'
         pd_counter = only_author and tags[0].goes_to_pd()
         objects = models.Book.objects.none()

-    
-    return newtagging_views.tagged_object_list(
+
+    return object_list(

         request,
         request,

-        tag_model=models.Tag,
-        queryset_or_model=objects,
-        tags=tags,
+        objects,

         template_name='catalogue/tagged_object_list.html',
         template_name='catalogue/tagged_object_list.html',

-        extra_context = {
+        extra_context={

             'categories': categories,
             'shelf_is_set': shelf_is_set,
             'only_author': only_author,
             'pd_counter': pd_counter,
             'user_is_owner': my_shelf_is_set,
             'formats_form': forms.DownloadFormatsForm(),
             'categories': categories,
             'shelf_is_set': shelf_is_set,
             'only_author': only_author,
             'pd_counter': pd_counter,
             'user_is_owner': my_shelf_is_set,
             'formats_form': forms.DownloadFormatsForm(),

-        },
+
+            'tags': tags,
+        }

     )
 
 
 def book_fragments(request, book_slug, theme_slug):
     book = get_object_or_404(models.Book, slug=book_slug)
     )
 
 
 def book_fragments(request, book_slug, theme_slug):
     book = get_object_or_404(models.Book, slug=book_slug)

-    book_tag = get_object_or_404(models.Tag, slug='l-' + book_slug)
-    theme = get_object_or_404(models.Tag, slug=theme_slug)
+    book_tag = get_object_or_404(models.Tag, slug='l-' + book_slug, category='book')
+    theme = get_object_or_404(models.Tag, slug=theme_slug, category='theme')

     fragments = models.Fragment.tagged.with_all([book_tag, theme])
     fragments = models.Fragment.tagged.with_all([book_tag, theme])

-    
+

     form = forms.SearchForm()
     return render_to_response('catalogue/book_fragments.html', locals(),
         context_instance=RequestContext(request))
     form = forms.SearchForm()
     return render_to_response('catalogue/book_fragments.html', locals(),
         context_instance=RequestContext(request))


@@ -166,14 +197,14 @@ def book_detail(request, slug):
     except models.Book.DoesNotExist:
         return book_stub_detail(request, slug)
 
     except models.Book.DoesNotExist:
         return book_stub_detail(request, slug)
 

-    book_tag = get_object_or_404(models.Tag, slug = 'l-' + slug)
+    book_tag = book.book_tag()

     tags = list(book.tags.filter(~Q(category='set')))
     categories = split_tags(tags)
     book_children = book.children.all().order_by('parent_number')
     extra_where = "catalogue_tag.category = 'theme'"
     book_themes = models.Tag.objects.related_for_model(book_tag, models.Fragment, counts=True, extra={'where': [extra_where]})
     extra_info = book.get_extra_info_value()
     tags = list(book.tags.filter(~Q(category='set')))
     categories = split_tags(tags)
     book_children = book.children.all().order_by('parent_number')
     extra_where = "catalogue_tag.category = 'theme'"
     book_themes = models.Tag.objects.related_for_model(book_tag, models.Fragment, counts=True, extra={'where': [extra_where]})
     extra_info = book.get_extra_info_value()

-    
+

     form = forms.SearchForm()
     return render_to_response('catalogue/book_detail.html', locals(),
         context_instance=RequestContext(request))
     form = forms.SearchForm()
     return render_to_response('catalogue/book_detail.html', locals(),
         context_instance=RequestContext(request))


@@ -183,10 +214,10 @@ def book_stub_detail(request, slug):
     book = get_object_or_404(models.BookStub, slug=slug)
     pd_counter = book.pd
     form = forms.SearchForm()
     book = get_object_or_404(models.BookStub, slug=slug)
     pd_counter = book.pd
     form = forms.SearchForm()

-    
+

     return render_to_response('catalogue/book_stub_detail.html', locals(),
         context_instance=RequestContext(request))
     return render_to_response('catalogue/book_stub_detail.html', locals(),
         context_instance=RequestContext(request))

-    
+

 
 def book_text(request, slug):
     book = get_object_or_404(models.Book, slug=slug)
 
 def book_text(request, slug):
     book = get_object_or_404(models.Book, slug=slug)


@@ -194,7 +225,7 @@ def book_text(request, slug):
     for fragment in book.fragments.all():
         for theme in fragment.tags.filter(category='theme'):
             book_themes.setdefault(theme, []).append(fragment)
     for fragment in book.fragments.all():
         for theme in fragment.tags.filter(category='theme'):
             book_themes.setdefault(theme, []).append(fragment)

-    
+

     book_themes = book_themes.items()
     book_themes.sort(key=lambda s: s[0].sort_key)
     return render_to_response('catalogue/book_text.html', locals(),
     book_themes = book_themes.items()
     book_themes.sort(key=lambda s: s[0].sort_key)
     return render_to_response('catalogue/book_text.html', locals(),


@@ -207,64 +238,75 @@ def book_text(request, slug):
 
 def _no_diacritics_regexp(query):
     """ returns a regexp for searching for a query without diacritics
 
 def _no_diacritics_regexp(query):
     """ returns a regexp for searching for a query without diacritics

-    
+

     should be locale-aware """
     should be locale-aware """

-    names = {'a':u'ą', 'c':u'ć', 'e':u'ę', 'l': u'ł', 'n':u'ń', 'o':u'ó', 's':u'ś', 'z':u'ź|ż'}
+    names = {
+        u'a':u'aąĄ', u'c':u'cćĆ', u'e':u'eęĘ', u'l': u'lłŁ', u'n':u'nńŃ', u'o':u'oóÓ', u's':u'sśŚ', u'z':u'zźżŹŻ',
+        u'ą':u'ąĄ', u'ć':u'ćĆ', u'ę':u'ęĘ', u'ł': u'łŁ', u'ń':u'ńŃ', u'ó':u'óÓ', u'ś':u'śŚ', u'ź':u'źŹ', u'ż':u'żŻ'
+        }

     def repl(m):
         l = m.group()
     def repl(m):
         l = m.group()

-        return "(%s|%s)" % (l, names[l])
-    return re.sub('[%s]'%(''.join(names.keys())), repl, query)
+        return u"(%s)" % '|'.join(names[l])
+    return re.sub(u'[%s]' % (u''.join(names.keys())), repl, query)
+
+def unicode_re_escape(query):
+    """ Unicode-friendly version of re.escape """
+    return re.sub('(?u)(\W)', r'\\\1', query)

 
 def _word_starts_with(name, prefix):
     """returns a Q object getting models having `name` contain a word
     starting with `prefix`
 
 def _word_starts_with(name, prefix):
     """returns a Q object getting models having `name` contain a word
     starting with `prefix`

+
+    We define word characters as alphanumeric and underscore, like in JS.
+
+    Works for MySQL, PostgreSQL, Oracle.
+    For SQLite, _sqlite* version is substituted for this.

     """
     kwargs = {}
     """
     kwargs = {}

-    if settings.DATABASE_ENGINE in ('mysql', 'postgresql_psycopg2', 'postgresql'):
-        prefix = _no_diacritics_regexp(re.escape(prefix))
-        # we could use a [[:<:]] (word start), 
-        # but we want both `xy` and `(xy` to catch `(xyz)`
-        kwargs['%s__iregex' % name] = u"(^|[^[:alpha:]])%s" % prefix
-    else:
-        # don't know how to do a generic regex
-        # checking for simple icontain instead
-        kwargs['%s__icontains' % name] = prefix
+
+    prefix = _no_diacritics_regexp(unicode_re_escape(prefix))
+    # can't use [[:<:]] (word start),
+    # but we want both `xy` and `(xy` to catch `(xyz)`
+    kwargs['%s__iregex' % name] = u"(^|[^[:alnum:]_])%s" % prefix
+

     return Q(**kwargs)
 
 
     return Q(**kwargs)
 
 

-def _tags_exact_matches(prefix, user):
-    book_stubs = models.BookStub.objects.filter(title__iexact = prefix)
-    books = models.Book.objects.filter(title__iexact = prefix)
-    book_stubs = filter(lambda x: x not in books, book_stubs)
-    tags = models.Tag.objects.filter(name__iexact = prefix)
-    if user.is_authenticated():
-        tags = tags.filter(~Q(category='book') & (~Q(category='set') | Q(user=user)))
-    else:
-        tags = tags.filter(~Q(category='book') & ~Q(category='set'))
+def _sqlite_word_starts_with(name, prefix):
+    """ version of _word_starts_with for SQLite
+
+    SQLite in Django uses Python re module
+    """
+    kwargs = {}
+    prefix = _no_diacritics_regexp(unicode_re_escape(prefix))
+    kwargs['%s__iregex' % name] = ur"(^|(?<=[^\wąćęłńóśźżĄĆĘŁŃÓŚŹŻ]))%s" % prefix
+    return Q(**kwargs)

 
 

-    return list(books) + list(tags) + list(book_stubs)

 
 

+if settings.DATABASE_ENGINE == 'sqlite3':
+    _word_starts_with = _sqlite_word_starts_with

 
 

-def _tags_starting_with(prefix, user):
+
+def _tags_starting_with(prefix, user=None):
+    prefix = prefix.lower()

     book_stubs = models.BookStub.objects.filter(_word_starts_with('title', prefix))
     books = models.Book.objects.filter(_word_starts_with('title', prefix))
     book_stubs = filter(lambda x: x not in books, book_stubs)
     tags = models.Tag.objects.filter(_word_starts_with('name', prefix))
     book_stubs = models.BookStub.objects.filter(_word_starts_with('title', prefix))
     books = models.Book.objects.filter(_word_starts_with('title', prefix))
     book_stubs = filter(lambda x: x not in books, book_stubs)
     tags = models.Tag.objects.filter(_word_starts_with('name', prefix))

-    if user.is_authenticated():
+    if user and user.is_authenticated():

         tags = tags.filter(~Q(category='book') & (~Q(category='set') | Q(user=user)))
     else:
         tags = tags.filter(~Q(category='book') & ~Q(category='set'))
 
     return list(books) + list(tags) + list(book_stubs)
         tags = tags.filter(~Q(category='book') & (~Q(category='set') | Q(user=user)))
     else:
         tags = tags.filter(~Q(category='book') & ~Q(category='set'))
 
     return list(books) + list(tags) + list(book_stubs)

-        

 
 
 def _get_result_link(match, tag_list):
     if isinstance(match, models.Book) or isinstance(match, models.BookStub):
         return match.get_absolute_url()
     else:
 
 
 def _get_result_link(match, tag_list):
     if isinstance(match, models.Book) or isinstance(match, models.BookStub):
         return match.get_absolute_url()
     else:

-        return reverse('catalogue.views.tagged_object_list', 
-            kwargs={'tags': '/'.join(tag.slug for tag in tag_list + [match])}
+        return reverse('catalogue.views.tagged_object_list',
+            kwargs={'tags': '/'.join(tag.url_chunk for tag in tag_list + [match])}

         )
 
 def _get_result_type(match):
         )
 
 def _get_result_type(match):


@@ -273,37 +315,53 @@ def _get_result_type(match):
     else:
         type = match.category
     return dict(models.TAG_CATEGORIES)[type]
     else:
         type = match.category
     return dict(models.TAG_CATEGORIES)[type]

-    
+
+
+
+def find_best_matches(query, user=None):
+    """ Finds a Book, Tag or Bookstub best matching a query.
+
+    Returns a with:
+      - zero elements when nothing is found,
+      - one element when a best result is found,
+      - more then one element on multiple exact matches
+
+    Raises a ValueError on too short a query.
+    """
+
+    query = query.lower()
+    if len(query) < 2:
+        raise ValueError("query must have at least two characters")
+
+    result = tuple(_tags_starting_with(query, user))
+    exact_matches = tuple(res for res in result if res.name.lower() == query)
+    if exact_matches:
+        return exact_matches
+    else:
+        return result[:1]

 
 
 def search(request):
     tags = request.GET.get('tags', '')
     prefix = request.GET.get('q', '')
 
 
 def search(request):
     tags = request.GET.get('tags', '')
     prefix = request.GET.get('q', '')

-    
+

     try:
         tag_list = models.Tag.get_tag_list(tags)
     except:
         tag_list = []
 
     try:
         tag_list = models.Tag.get_tag_list(tags)
     except:
         tag_list = []
 

-    # Prefix must have at least 2 characters
-    if len(prefix) < 2:
+    try:
+        result = find_best_matches(prefix, request.user)
+    except ValueError:

         return render_to_response('catalogue/search_too_short.html', {'tags':tag_list, 'prefix':prefix},
             context_instance=RequestContext(request))
         return render_to_response('catalogue/search_too_short.html', {'tags':tag_list, 'prefix':prefix},
             context_instance=RequestContext(request))

-    
-    result = _tags_exact_matches(prefix, request.user)
-    
-    if len(result) > 1:
-        # multiple exact matches
-        return render_to_response('catalogue/search_multiple_hits.html', 
+
+    if len(result) == 1:
+        return HttpResponseRedirect(_get_result_link(result[0], tag_list))
+    elif len(result) > 1:
+        return render_to_response('catalogue/search_multiple_hits.html',

             {'tags':tag_list, 'prefix':prefix, 'results':((x, _get_result_link(x, tag_list), _get_result_type(x)) for x in result)},
             context_instance=RequestContext(request))
             {'tags':tag_list, 'prefix':prefix, 'results':((x, _get_result_link(x, tag_list), _get_result_type(x)) for x in result)},
             context_instance=RequestContext(request))

-    
-    if not result:
-        # no exact matches
-        result = _tags_starting_with(prefix, request.user)
-    
-    if result:
-        return HttpResponseRedirect(_get_result_link(result[0], tag_list))

     else:
         return render_to_response('catalogue/search_no_hits.html', {'tags':tag_list, 'prefix':prefix},
             context_instance=RequestContext(request))
     else:
         return render_to_response('catalogue/search_no_hits.html', {'tags':tag_list, 'prefix':prefix},
             context_instance=RequestContext(request))


@@ -314,9 +372,8 @@ def tags_starting_with(request):
     # Prefix must have at least 2 characters
     if len(prefix) < 2:
         return HttpResponse('')
     # Prefix must have at least 2 characters
     if len(prefix) < 2:
         return HttpResponse('')

-    
-    return HttpResponse('\n'.join(tag.name for tag in _tags_starting_with(prefix, request.user)))

 
 

+    return HttpResponse('\n'.join(tag.name for tag in _tags_starting_with(prefix, request.user)))

 
 # ====================
 # = Shelf management =
 
 # ====================
 # = Shelf management =


@@ -334,24 +391,24 @@ def book_sets(request, slug):
     book = get_object_or_404(models.Book, slug=slug)
     user_sets = models.Tag.objects.filter(category='set', user=request.user)
     book_sets = book.tags.filter(category='set', user=request.user)
     book = get_object_or_404(models.Book, slug=slug)
     user_sets = models.Tag.objects.filter(category='set', user=request.user)
     book_sets = book.tags.filter(category='set', user=request.user)

-    
+

     if not request.user.is_authenticated():
         return HttpResponse(_('<p>To maintain your shelves you need to be logged in.</p>'))
     if not request.user.is_authenticated():
         return HttpResponse(_('<p>To maintain your shelves you need to be logged in.</p>'))

-    
+

     if request.method == 'POST':
         form = forms.ObjectSetsForm(book, request.user, request.POST)
         if form.is_valid():
             old_shelves = list(book.tags.filter(category='set'))
             new_shelves = [models.Tag.objects.get(pk=id) for id in form.cleaned_data['set_ids']]
     if request.method == 'POST':
         form = forms.ObjectSetsForm(book, request.user, request.POST)
         if form.is_valid():
             old_shelves = list(book.tags.filter(category='set'))
             new_shelves = [models.Tag.objects.get(pk=id) for id in form.cleaned_data['set_ids']]

-            
+

             for shelf in [shelf for shelf in old_shelves if shelf not in new_shelves]:
                 shelf.book_count -= 1
                 shelf.save()
             for shelf in [shelf for shelf in old_shelves if shelf not in new_shelves]:
                 shelf.book_count -= 1
                 shelf.save()

-                
+

             for shelf in [shelf for shelf in new_shelves if shelf not in old_shelves]:
                 shelf.book_count += 1
                 shelf.save()
             for shelf in [shelf for shelf in new_shelves if shelf not in old_shelves]:
                 shelf.book_count += 1
                 shelf.save()

-            
+

             book.tags = new_shelves + list(book.tags.filter(~Q(category='set') | ~Q(user=request.user)))
             if request.is_ajax():
                 return HttpResponse(_('<p>Shelves were sucessfully saved.</p>'))
             book.tags = new_shelves + list(book.tags.filter(~Q(category='set') | ~Q(user=request.user)))
             if request.is_ajax():
                 return HttpResponse(_('<p>Shelves were sucessfully saved.</p>'))


@@ -360,7 +417,7 @@ def book_sets(request, slug):
     else:
         form = forms.ObjectSetsForm(book, request.user)
         new_set_form = forms.NewSetForm()
     else:
         form = forms.ObjectSetsForm(book, request.user)
         new_set_form = forms.NewSetForm()

-    
+

     return render_to_response('catalogue/book_sets.html', locals(),
         context_instance=RequestContext(request))
 
     return render_to_response('catalogue/book_sets.html', locals(),
         context_instance=RequestContext(request))
 


@@ -371,7 +428,7 @@ def book_sets(request, slug):
 def remove_from_shelf(request, shelf, book):
     book = get_object_or_404(models.Book, slug=book)
     shelf = get_object_or_404(models.Tag, slug=shelf, category='set', user=request.user)
 def remove_from_shelf(request, shelf, book):
     book = get_object_or_404(models.Book, slug=book)
     shelf = get_object_or_404(models.Tag, slug=shelf, category='set', user=request.user)

-    
+

     if shelf in book.tags:
         models.Tag.objects.remove_tag(book, shelf)
 
     if shelf in book.tags:
         models.Tag.objects.remove_tag(book, shelf)
 


@@ -401,25 +458,28 @@ def download_shelf(request, slug):
     """"
     Create a ZIP archive on disk and transmit it in chunks of 8KB,
     without loading the whole file into memory. A similar approach can
     """"
     Create a ZIP archive on disk and transmit it in chunks of 8KB,
     without loading the whole file into memory. A similar approach can

-    be used for large dynamic PDF files.                                        
+    be used for large dynamic PDF files.

     """
     shelf = get_object_or_404(models.Tag, slug=slug, category='set')
     """
     shelf = get_object_or_404(models.Tag, slug=slug, category='set')

-    
+

     formats = []
     form = forms.DownloadFormatsForm(request.GET)
     if form.is_valid():
         formats = form.cleaned_data['formats']
     if len(formats) == 0:
     formats = []
     form = forms.DownloadFormatsForm(request.GET)
     if form.is_valid():
         formats = form.cleaned_data['formats']
     if len(formats) == 0:

-        formats = ['pdf', 'odt', 'txt', 'mp3', 'ogg']
-    
+        formats = ['pdf', 'epub', 'odt', 'txt', 'mp3', 'ogg']
+

     # Create a ZIP archive
     temp = tempfile.TemporaryFile()
     archive = zipfile.ZipFile(temp, 'w')
     # Create a ZIP archive
     temp = tempfile.TemporaryFile()
     archive = zipfile.ZipFile(temp, 'w')

-    
+

     for book in collect_books(models.Book.tagged.with_all(shelf)):
         if 'pdf' in formats and book.pdf_file:
             filename = book.pdf_file.path
             archive.write(filename, str('%s.pdf' % book.slug))
     for book in collect_books(models.Book.tagged.with_all(shelf)):
         if 'pdf' in formats and book.pdf_file:
             filename = book.pdf_file.path
             archive.write(filename, str('%s.pdf' % book.slug))

+        if 'epub' in formats and book.epub_file:
+            filename = book.epub_file.path
+            archive.write(filename, str('%s.epub' % book.slug))

         if 'odt' in formats and book.odt_file:
             filename = book.odt_file.path
             archive.write(filename, str('%s.odt' % book.slug))
         if 'odt' in formats and book.odt_file:
             filename = book.odt_file.path
             archive.write(filename, str('%s.odt' % book.slug))


@@ -433,11 +493,11 @@ def download_shelf(request, slug):
             filename = book.ogg_file.path
             archive.write(filename, str('%s.ogg' % book.slug))
     archive.close()
             filename = book.ogg_file.path
             archive.write(filename, str('%s.ogg' % book.slug))
     archive.close()

-    
+

     response = HttpResponse(content_type='application/zip', mimetype='application/x-zip-compressed')
     response['Content-Disposition'] = 'attachment; filename=%s.zip' % shelf.sort_key
     response['Content-Length'] = temp.tell()
     response = HttpResponse(content_type='application/zip', mimetype='application/x-zip-compressed')
     response['Content-Disposition'] = 'attachment; filename=%s.zip' % shelf.sort_key
     response['Content-Length'] = temp.tell()

-    
+

     temp.seek(0)
     response.write(temp.read())
     return response
     temp.seek(0)
     response.write(temp.read())
     return response


@@ -450,11 +510,13 @@ def shelf_book_formats(request, shelf):
     """
     shelf = get_object_or_404(models.Tag, slug=shelf, category='set')
 
     """
     shelf = get_object_or_404(models.Tag, slug=shelf, category='set')
 

-    formats = {'pdf': False, 'odt': False, 'txt': False, 'mp3': False, 'ogg': False}
-    
+    formats = {'pdf': False, 'epub': False, 'odt': False, 'txt': False, 'mp3': False, 'ogg': False}
+

     for book in collect_books(models.Book.tagged.with_all(shelf)):
         if book.pdf_file:
             formats['pdf'] = True
     for book in collect_books(models.Book.tagged.with_all(shelf)):
         if book.pdf_file:
             formats['pdf'] = True

+        if book.epub_file:
+            formats['epub'] = True

         if book.odt_file:
             formats['odt'] = True
         if book.txt_file:
         if book.odt_file:
             formats['odt'] = True
         if book.txt_file:


@@ -518,7 +580,7 @@ def register(request):
     if registration_form.is_valid():
         user = registration_form.save()
         user = auth.authenticate(
     if registration_form.is_valid():
         user = registration_form.save()
         user = auth.authenticate(

-            username=registration_form.cleaned_data['username'], 
+            username=registration_form.cleaned_data['username'],

             password=registration_form.cleaned_data['password1']
         )
         auth.login(request, user)
             password=registration_form.cleaned_data['password1']
         )
         auth.login(request, user)