src/catalogue/views.py

   1 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   3 #
   4 from collections import OrderedDict
   5 import random
   6 import re
   7 from urllib.parse import quote_plus
   8
   9 from django.conf import settings
  10 from django.template.loader import render_to_string
  11 from django.shortcuts import get_object_or_404, render, redirect
  12 from django.http import HttpResponse, HttpResponseRedirect, Http404, HttpResponsePermanentRedirect
  13 from django.urls import reverse
  14 from django.db.models import Q, QuerySet
  15 from django.contrib.auth.decorators import login_required, user_passes_test
  16 from django.utils import translation
  17 from django.utils.translation import gettext_lazy
  18 from django.views.decorators.cache import never_cache
  19 from django.views.generic import TemplateView
  20
  21 from ajaxable.utils import AjaxableFormView
  22 from club.forms import DonationStep1Form
  23 from club.models import Club
  24 from annoy.models import DynamicTextInsert
  25 from pdcounter import views as pdcounter_views
  26 from picture.models import Picture, PictureArea
  27 from wolnelektury.utils import is_ajax
  28 from catalogue import constants
  29 from catalogue import forms
  30 from catalogue.helpers import get_top_level_related_tags
  31 from catalogue.models import Book, Collection, Tag, Fragment
  32 from catalogue.models.tag import TagRelation
  33 from catalogue.utils import split_tags
  34 from catalogue.models.tag import prefetch_relations
  35
  36 staff_required = user_passes_test(lambda user: user.is_staff)
  37
  38
  39 def catalogue(request):
  40     return render(request, 'catalogue/catalogue.html', {
  41         'books': Book.objects.filter(findable=True, parent=None),
  42         'pictures': Picture.objects.all(),
  43         'collections': Collection.objects.filter(listed=True),
  44         'active_menu_item': 'all_works',
  45     })
  46
  47
  48 def daisy_list(request):
  49     return object_list(request, Book.objects.filter(media__type='daisy'))
  50
  51
  52 def collection(request, slug):
  53     coll = get_object_or_404(Collection, slug=slug)
  54     template_name = 'catalogue/collection.html'
  55     return render(request, template_name, {
  56         'collection': coll,
  57         'active_menu_item': 'collections',
  58     })
  59
  60
  61 def differentiate_tags(request, tags, ambiguous_slugs):
  62     beginning = '/'.join(tag.url_chunk for tag in tags)
  63     unparsed = '/'.join(ambiguous_slugs[1:])
  64     options = []
  65     for tag in Tag.objects.filter(slug=ambiguous_slugs[0]):
  66         options.append({
  67             'url_args': '/'.join((beginning, tag.url_chunk, unparsed)).strip('/'),
  68             'tags': [tag]
  69         })
  70     return render(
  71         request,
  72         'catalogue/differentiate_tags.html',
  73         {'tags': tags, 'options': options, 'unparsed': ambiguous_slugs[1:]}
  74     )
  75
  76
  77 from django.db.models import FilteredRelation, Q
  78 from django.views.decorators.cache import cache_control
  79 from django.views.decorators.vary import vary_on_headers
  80 from django.utils.decorators import method_decorator
  81
  82
  83 @method_decorator([
  84     vary_on_headers('X-Requested-With'),
  85     cache_control(max_age=1),
  86 ], 'dispatch')
  87 class ObjectListView(TemplateView):
  88     page_size = 100
  89     themed_page_size = 10
  90     item_template_name = ''
  91     orderings = {}
  92     default_ordering = None
  93
  94     def analyse(self):
  95         self.is_themed = False
  96         self.ctx = ctx = {}
  97         ctx['tags'] = []
  98
  99     def dispatch(self, *args, **kwargs):
 100         try:
 101             self.analyse()
 102         except ResponseInstead as e:
 103             return e.response
 104         return super().dispatch(*args, **kwargs)
 105
 106     def get_orderings(self):
 107         order = self.get_order()
 108         return [
 109             {
 110                 "slug": k,
 111                 "name": v[1],
 112                 "active": k == order,
 113                 "default": v[0] is None,
 114             }
 115             for k, v in self.orderings.items()
 116         ]
 117
 118     def get_order(self):
 119         order = self.request.GET.get('order')
 120         if order not in self.orderings:
 121             order = self.default_ordering
 122         return order
 123
 124     def order(self, qs):
 125         order_tag = self.get_order()
 126         if order_tag:
 127             order = self.orderings[order_tag]
 128             order_by = order[0]
 129             if order_by:
 130                 qs = qs.order_by(order_by)
 131         return qs
 132
 133     def search(self, qs):
 134         return qs
 135
 136     def get_template_names(self):
 137         if is_ajax(self.request) or self.request.GET.get('dyn'):
 138             if self.is_themed:
 139                 return self.dynamic_themed_template_name
 140             else:
 141                 return self.dynamic_template_name
 142         else:
 143             if self.is_themed:
 144                 return self.themed_template_name
 145             else:
 146                 return self.template_name
 147
 148     def get_context_data(self, **kwargs):
 149         ctx = super().get_context_data()
 150         ctx.update(self.ctx)
 151         qs = self.get_queryset()
 152         qs = self.search(qs)
 153         qs = self.order(qs)
 154
 155         ctx['object_list'] = qs
 156         ctx['suggested_tags'] = self.get_suggested_tags(qs)
 157         ctx['suggested_tags_by_category'] = split_tags(ctx['suggested_tags'])
 158         return ctx
 159
 160
 161 class BookList(ObjectListView):
 162     title = gettext_lazy('Literatura')
 163     list_type = 'books'
 164     template_name = 'catalogue/book_list.html'
 165     dynamic_template_name = 'catalogue/dynamic_book_list.html'
 166     themed_template_name = 'catalogue/themed_book_list.html'
 167     dynamic_themed_template_name = 'catalogue/dynamic_themed_book_list.html'
 168
 169     orderings = {
 170         'pop': ('-popularity__count', gettext_lazy('najpopularniejsze')),
 171         'alpha': (None, gettext_lazy('alfabetycznie')),
 172     }
 173     default_ordering = 'alpha'
 174
 175     def get_queryset(self):
 176         return Book.objects.filter(parent=None, findable=True)
 177
 178     def search(self, qs):
 179         term = self.request.GET.get('search')
 180         if term:
 181             meta_rels = TagRelation.objects.filter(tag__category='author')
 182             # TODO: search tags in currently displaying language
 183             if self.is_themed:
 184                 rels = meta_rels.filter(tag__name_pl__icontains=term)
 185                 qs = qs.filter(
 186                     Q(book__title__icontains=term) |
 187                     Q(tag_relations__in=rels) |
 188                     Q(text__icontains=term)
 189                 ).distinct()
 190             else:
 191                 qs = qs.annotate(
 192                     meta=FilteredRelation('tag_relations', condition=Q(tag_relations__in=meta_rels))
 193                 )
 194                 qs = qs.filter(Q(title__icontains=term) | Q(meta__tag__name_pl__icontains=term)).distinct()
 195         return qs
 196
 197
 198 class ArtList(ObjectListView):
 199     template_name = 'catalogue/book_list.html'
 200     dynamic_template_name = 'catalogue/dynamic_book_list.html'
 201     title = gettext_lazy('Sztuka')
 202     list_type = 'gallery'
 203
 204     def get_queryset(self):
 205         return Picture.objects.all()
 206
 207     def search(self, qs):
 208         term = self.request.GET.get('search')
 209         if term:
 210             qs = qs.filter(Q(title__icontains=term) | Q(tag_relations__tag__name_pl__icontains=term)).distinct()
 211         return qs
 212
 213
 214 class LiteratureView(BookList):
 215     def get_suggested_tags(self, queryset):
 216         tags = list(get_top_level_related_tags([]))
 217         tags.sort(key=lambda t: -t.count)
 218         if self.request.user.is_authenticated:
 219             tags.extend(list(Tag.objects.filter(user=self.request.user).exclude(name='')))
 220         return tags
 221
 222
 223 class AudiobooksView(LiteratureView):
 224     title = gettext_lazy('Audiobooki')
 225     list_type = 'audiobooks'
 226
 227     def get_queryset(self):
 228         return Book.objects.filter(findable=True, media__type='mp3').distinct()
 229
 230
 231 class GalleryView(ArtList):
 232     def get_suggested_tags(self, queryset):
 233         return Tag.objects.usage_for_queryset(
 234             queryset,
 235             counts=True
 236         ).exclude(pk__in=[t.id for t in self.ctx['tags']]).order_by('-count')
 237
 238
 239 class TaggedObjectList(BookList):
 240     def analyse(self):
 241         super().analyse()
 242         self.ctx['tags'] = analyse_tags(self.request, self.kwargs['tags'])
 243         self.ctx['fragment_tags'] = [t for t in self.ctx['tags'] if t.category in ('theme', 'object')]
 244         self.ctx['work_tags'] = [t for t in self.ctx['tags'] if t not in self.ctx['fragment_tags']]
 245         self.is_themed = self.ctx['has_theme'] = bool(self.ctx['fragment_tags'])
 246         if self.is_themed:
 247             self.ctx['main_tag'] = self.ctx['fragment_tags'][0]
 248         elif self.ctx['tags']:
 249             self.ctx['main_tag'] = self.ctx['tags'][0]
 250         else:
 251             self.ctx['main_tag'] = None
 252         self.ctx['filtering_tags'] = [
 253             t for t in self.ctx['tags']
 254             if t is not self.ctx['main_tag']
 255         ]
 256
 257     def get_queryset(self):
 258         qs = Book.tagged.with_all(self.ctx['work_tags']).filter(findable=True)
 259         qs = qs.exclude(ancestor__in=qs)
 260         if self.is_themed:
 261             fqs = Fragment.tagged.with_all(self.ctx['fragment_tags'])
 262             if self.ctx['work_tags']:
 263                 fqs = fqs.filter(
 264                     Q(book__in=qs) | Q(book__ancestor__in=qs)
 265                 )
 266             qs = fqs
 267         return qs
 268
 269     def get_suggested_tags(self, queryset):
 270         tag_ids = [t.id for t in self.ctx['tags']]
 271         if self.is_themed:
 272             related_tags = []
 273             current_books = self.get_queryset().values_list('book', flat=True).distinct()
 274             containing_books = Book.objects.filter(Q(id__in=current_books) | Q(children__in=current_books))
 275
 276             related_tags.extend(list(
 277                 Tag.objects.usage_for_queryset(
 278                     containing_books,
 279                 ).exclude(category='set').exclude(pk__in=tag_ids)
 280             ))
 281             if self.request.user.is_authenticated:
 282                 related_tags.extend(list(
 283                     Tag.objects.usage_for_queryset(
 284                         containing_books
 285                     ).filter(
 286                         user=self.request.user
 287                     ).exclude(name='').exclude(pk__in=tag_ids)
 288                 ))
 289         else:
 290             related_tags = list(get_top_level_related_tags(self.ctx['tags']))
 291             if self.request.user.is_authenticated:
 292                 qs = Book.tagged.with_all(self.ctx['tags']).filter(findable=True)
 293                 related_tags.extend(list(
 294                     Tag.objects.usage_for_queryset(
 295                         qs
 296                     ).filter(
 297                         user=self.request.user
 298                     ).exclude(name='').exclude(pk__in=tag_ids)
 299                 ))
 300
 301             fragments = Fragment.objects.filter(
 302                 Q(book__in=queryset) | Q(book__ancestor__in=queryset)
 303             )
 304             related_tags.extend(
 305                 Tag.objects.usage_for_queryset(
 306                     fragments, counts=True
 307                 ).filter(category__in=('theme', 'object')).exclude(pk__in=tag_ids)
 308             .only('name', 'sort_key', 'category', 'slug'))
 309
 310         return related_tags
 311
 312
 313
 314 def object_list(request, objects, fragments=None, related_tags=None, tags=None,
 315                 list_type='books', extra=None):
 316     if not tags:
 317         tags = []
 318     tag_ids = [tag.pk for tag in tags]
 319
 320     related_tag_lists = []
 321     if related_tags:
 322         related_tag_lists.append(related_tags)
 323     else:
 324         related_tag_lists.append(
 325             Tag.objects.usage_for_queryset(
 326                 objects, counts=True
 327             ).exclude(category='set').exclude(pk__in=tag_ids))
 328         if request.user.is_authenticated:
 329             related_tag_lists.append(
 330                 Tag.objects.usage_for_queryset(
 331                     objects, counts=True
 332                 ).filter(
 333                     user=request.user
 334                 ).exclude(name='').exclude(pk__in=tag_ids)
 335             )
 336     if not (extra and extra.get('theme_is_set')):
 337         if fragments is None:
 338             if list_type == 'gallery':
 339                 fragments = PictureArea.objects.filter(picture__in=objects)
 340             else:
 341                 fragments = Fragment.objects.filter(book__in=objects)
 342         related_tag_lists.append(
 343             Tag.objects.usage_for_queryset(
 344                 fragments, counts=True
 345             ).filter(category='theme').exclude(pk__in=tag_ids)
 346             .only('name', 'sort_key', 'category', 'slug'))
 347         if isinstance(objects, QuerySet):
 348             objects = prefetch_relations(objects, 'author')
 349
 350
 351     categories = split_tags(*related_tag_lists)
 352     suggest = []
 353     for c in ['set', 'author', 'epoch', 'kind', 'genre']:
 354         suggest.extend(sorted(categories[c], key=lambda t: -t.count))
 355
 356     objects = list(objects)
 357
 358     if not objects and len(tags) == 1 and list_type == 'books':
 359         if PictureArea.tagged.with_any(tags).exists() or Picture.tagged.with_any(tags).exists():
 360             return redirect('tagged_object_list_gallery', '/'.join(tag.url_chunk for tag in tags))
 361
 362     if len(objects) > 3:
 363         best = random.sample(objects, 3)
 364     else:
 365         best = objects
 366
 367     result = {
 368         'object_list': objects,
 369         'categories': categories,
 370         'suggest': suggest,
 371         'list_type': list_type,
 372         'tags': tags,
 373         'main_tag': tags[0] if tags else None,
 374
 375         'formats_form': forms.DownloadFormatsForm(),
 376         'best': best,
 377         'active_menu_item': list_type,
 378     }
 379     if extra:
 380         result.update(extra)
 381
 382     has_theme = any(((theme := x).category == 'theme' for x in tags))
 383     if has_theme:
 384         result['main_tag'] = theme
 385         template = 'catalogue/theme_detail.html'
 386     else:
 387         template = 'catalogue/author_detail.html'
 388
 389     return render(
 390         request, template, result,
 391     )
 392
 393
 394 class ResponseInstead(Exception):
 395     def __init__(self, response):
 396         super(ResponseInstead, self).__init__()
 397         self.response = response
 398
 399
 400 def analyse_tags(request, tag_str):
 401     try:
 402         tags = Tag.get_tag_list(tag_str)
 403     except Tag.DoesNotExist:
 404         # Perhaps the user is asking about an author in Public Domain
 405         # counter (they are not represented in tags)
 406         chunks = tag_str.split('/')
 407         if len(chunks) == 2 and chunks[0] == 'autor':
 408             raise ResponseInstead(pdcounter_views.author_detail(request, chunks[1]))
 409         raise Http404
 410     except Tag.MultipleObjectsReturned as e:
 411         # Ask the user to disambiguate
 412         raise ResponseInstead(differentiate_tags(request, e.tags, e.ambiguous_slugs))
 413     except Tag.UrlDeprecationWarning as e:
 414         raise ResponseInstead(HttpResponsePermanentRedirect(
 415             reverse('tagged_object_list', args=['/'.join(tag.url_chunk for tag in e.tags)])))
 416
 417     if not tags:
 418         raise Http404
 419     try:
 420         if len(tags) > settings.MAX_TAG_LIST:
 421             raise Http404
 422     except AttributeError:
 423         pass
 424
 425     return tags
 426
 427
 428 def theme_list(request, tags, list_type):
 429     shelf_tags = [tag for tag in tags if tag.category == 'set']
 430     fragment_tags = [tag for tag in tags if tag.category != 'set']
 431     if list_type == 'gallery':
 432         fragments = PictureArea.tagged.with_all(fragment_tags)
 433     else:
 434         fragments = Fragment.tagged.with_all(fragment_tags)
 435
 436     if shelf_tags:
 437         # TODO: Pictures on shelves not supported yet.
 438         books = Book.tagged.with_all(shelf_tags).order_by()
 439         fragments = fragments.filter(Q(book__in=books) | Q(book__ancestor__in=books))
 440     elif list_type == 'books':
 441         fragments = fragments.filter(book__findable=True)
 442
 443     if not fragments and len(tags) == 1 and list_type == 'books':
 444         if PictureArea.tagged.with_any(tags).exists() or Picture.tagged.with_any(tags).exists():
 445             return redirect('tagged_object_list_gallery', '/'.join(tag.url_chunk for tag in tags))
 446
 447     return object_list(request, fragments, tags=tags, list_type=list_type, extra={
 448         'theme_is_set': True,
 449         'active_menu_item': 'theme',
 450     })
 451
 452
 453 def tagged_object_list(request, tags, list_type):
 454     if list_type in ('books', 'audiobooks'):
 455         return TaggedObjectList.as_view()(request, tags=tags)
 456
 457     try:
 458         tags = analyse_tags(request, tags)
 459     except ResponseInstead as e:
 460         return e.response
 461
 462     if list_type == 'gallery' and any(tag.category == 'set' for tag in tags):
 463         raise Http404
 464
 465     if any(tag.category in ('theme', 'thing') for tag in tags):
 466         return theme_list(request, tags, list_type=list_type)
 467
 468     if list_type == 'books':
 469         books = Book.tagged.with_all(tags)
 470
 471         if any(tag.category == 'set' for tag in tags):
 472             params = {'objects': books}
 473         else:
 474             books = books.filter(findable=True)
 475             params = {
 476                 'objects': Book.tagged_top_level(tags).filter(findable=True),
 477                 'fragments': Fragment.objects.filter(book__in=books),
 478                 'related_tags': get_top_level_related_tags(tags),
 479             }
 480     elif list_type == 'gallery':
 481         params = {'objects': Picture.tagged.with_all(tags)}
 482     elif list_type == 'audiobooks':
 483         audiobooks = Book.objects.filter(findable=True, media__type__in=('mp3', 'ogg')).distinct()
 484         params = {
 485             'objects': Book.tagged.with_all(tags, audiobooks),
 486             'extra': {
 487                 'daisy': Book.tagged.with_all(
 488                     tags, audiobooks.filter(media__type='daisy').distinct()
 489                 ),
 490             }
 491         }
 492     else:
 493         raise Http404
 494
 495     return object_list(request, tags=tags, list_type=list_type, **params)
 496
 497
 498 def book_fragments(request, slug, theme_slug):
 499     book = get_object_or_404(Book, slug=slug)
 500     theme = get_object_or_404(Tag, slug=theme_slug, category='theme')
 501     fragments = Fragment.tagged.with_all([theme]).filter(
 502         Q(book=book) | Q(book__ancestor=book))
 503
 504     template_name = 'catalogue/book_fragments.html'
 505     return render(
 506         request,
 507         template_name,
 508         {
 509             'book': book,
 510             'theme': theme,
 511             'fragments': fragments,
 512             'active_menu_item': 'books',
 513         })
 514
 515
 516 @never_cache
 517 def book_detail(request, slug):
 518     try:
 519         book = Book.objects.get(slug=slug)
 520     except Book.DoesNotExist:
 521         return pdcounter_views.book_stub_detail(request, slug)
 522
 523     return render(
 524         request,
 525         'catalogue/book_detail.html',
 526         {
 527             'book': book,
 528             'accessible': book.is_accessible_to(request.user),
 529             'book_children': book.children.all().order_by('parent_number', 'sort_key'),
 530             'active_menu_item': 'books',
 531             'club': Club.objects.first() if book.preview else None,
 532             'donation_form': DonationStep1Form(),
 533         })
 534
 535
 536 def book_text(request, slug):
 537     book = get_object_or_404(Book, slug=slug)
 538
 539     if not book.is_accessible_to(request.user):
 540         return HttpResponseRedirect(book.get_absolute_url())
 541
 542     if not book.has_html_file():
 543         raise Http404
 544     with book.html_file.open('r') as f:
 545         book_text = f.read()
 546
 547     return render(request, 'catalogue/book_text.html', {
 548         'book': book,
 549         'book_text': book_text,
 550         'inserts': DynamicTextInsert.get_all(request)
 551     })
 552
 553
 554 # =========
 555 # = Admin =
 556 # =========
 557 @login_required
 558 @staff_required
 559 def import_book(request):
 560     """docstring for import_book"""
 561     book_import_form = forms.BookImportForm(request.POST, request.FILES)
 562     if book_import_form.is_valid():
 563         try:
 564             book_import_form.save()
 565         except:
 566             import sys
 567             import pprint
 568             import traceback
 569             info = sys.exc_info()
 570             exception = pprint.pformat(info[1])
 571             tb = '\n'.join(traceback.format_tb(info[2]))
 572             return HttpResponse(
 573                 "Błąd: %(exception)s\n\n%(tb)s" % {
 574                     'exception': exception, 'tb': tb
 575                 },
 576                 content_type='text/plain'
 577             )
 578         return HttpResponse("Książka zaimportowana")
 579     return HttpResponse("Błąd podczas importowania pliku: %r" % book_import_form.errors)
 580
 581
 582 # info views for API
 583
 584 def book_info(request, book_id, lang='pl'):
 585     book = get_object_or_404(Book, id=book_id)
 586     # set language by hand
 587     translation.activate(lang)
 588     return render(request, 'catalogue/book_info.html', {'book': book})
 589
 590
 591 def tag_info(request, tag_id):
 592     tag = get_object_or_404(Tag, id=tag_id)
 593     return HttpResponse(tag.description)
 594
 595
 596 @never_cache
 597 def embargo_link(request, key, format_, slug):
 598     book = get_object_or_404(Book, slug=slug)
 599     if format_ not in Book.formats:
 600         raise Http404
 601     if key != book.preview_key:
 602         raise Http404
 603     media_file = book.get_media(format_)
 604     if not book.preview:
 605         return HttpResponseRedirect(media_file.url)
 606     return HttpResponse(media_file, content_type=constants.EBOOK_CONTENT_TYPES[format_])
 607
 608
 609 def download_zip(request, file_format=None, media_format=None, slug=None):
 610     if file_format:
 611         url = Book.zip_format(file_format)
 612     elif media_format and slug is not None:
 613         book = get_object_or_404(Book, slug=slug)
 614         url = book.zip_audiobooks(media_format)
 615     else:
 616         raise Http404('No format specified for zip package')
 617     return HttpResponseRedirect(quote_plus(settings.MEDIA_URL + url, safe='/?='))
 618
 619
 620 class CustomPDFFormView(AjaxableFormView):
 621     form_class = forms.CustomPDFForm
 622     title = gettext_lazy('Stwórz własny PDF')
 623     submit = gettext_lazy('Pobierz')
 624     template = 'catalogue/custom_pdf_form.html'
 625     honeypot = True
 626
 627     def __call__(self, *args, **kwargs):
 628         if settings.NO_CUSTOM_PDF:
 629             raise Http404('Custom PDF is disabled')
 630         return super(CustomPDFFormView, self).__call__(*args, **kwargs)
 631
 632     def form_args(self, request, obj):
 633         """Override to parse view args and give additional args to the form."""
 634         return (obj,), {}
 635
 636     def validate_object(self, obj, request):
 637         book = obj
 638         if not book.is_accessible_to(request.user):
 639             return HttpResponseRedirect(book.get_absolute_url())
 640         return super(CustomPDFFormView, self).validate_object(obj, request)
 641
 642     def get_object(self, request, slug, *args, **kwargs):
 643         book = get_object_or_404(Book, slug=slug)
 644         return book
 645
 646     def context_description(self, request, obj):
 647         return obj.pretty_title()
 648
 649
 650 def tag_catalogue(request, category):
 651     if category == 'theme':
 652         tags = Tag.objects.usage_for_model(
 653             Fragment, counts=True).filter(category='theme')
 654     else:
 655         tags = list(get_top_level_related_tags((), categories=(category,)))
 656
 657     described_tags = [tag for tag in tags if tag.description]
 658
 659     if len(described_tags) > 4:
 660         best = random.sample(described_tags, 4)
 661     else:
 662         best = described_tags
 663
 664     template_name = 'catalogue/tag_catalogue.html'
 665     return render(request, template_name, {
 666         'tags': tags,
 667         'best': best,
 668         'title': constants.CATEGORIES_NAME_PLURAL[category],
 669         'whole_category': constants.WHOLE_CATEGORY[category],
 670         'active_menu_item': 'theme' if category == 'theme' else None,
 671     })
 672
 673
 674 def collections(request):
 675     objects = Collection.objects.filter(listed=True)
 676
 677     if len(objects) > 3:
 678         best = random.sample(list(objects), 4)
 679     else:
 680         best = objects
 681
 682     template_name = 'catalogue/collections.html'
 683     return render(request, template_name, {
 684         'objects': objects,
 685         'best': best,
 686         'active_menu_item': 'collections'
 687     })
 688
 689
 690 def ridero_cover(request, slug):
 691     from librarian.cover import make_cover
 692     wldoc = Book.objects.get(slug=slug).wldocument()
 693     cover = make_cover(wldoc.book_info, width=980, bleed=20, format='PNG')
 694     response = HttpResponse(content_type="image/png")
 695     cover.save(response)
 696     return response
 697
 698
 699 def get_isbn(request, book_format, slug):
 700     book = Book.objects.get(slug=slug)
 701     return HttpResponse(book.get_extra_info_json().get('isbn_%s' % book_format))