apps/catalogue/views.py

   1 # -*- coding: utf-8 -*-
   2 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   3 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   4 #
   5 import tempfile
   6 import zipfile
   7 import sys
   8 import pprint
   9 import traceback
  10 import re
  11 import itertools
  12 from operator import itemgetter
  13
  14 from django.conf import settings
  15 from django.template import RequestContext
  16 from django.shortcuts import render_to_response, get_object_or_404
  17 from django.http import HttpResponse, HttpResponseRedirect, Http404
  18 from django.core.urlresolvers import reverse
  19 from django.db.models import Q
  20 from django.contrib.auth.decorators import login_required, user_passes_test
  21 from django.utils.datastructures import SortedDict
  22 from django.views.decorators.http import require_POST
  23 from django.contrib import auth
  24 from django.contrib.auth.forms import UserCreationForm, AuthenticationForm
  25 from django.utils import simplejson
  26 from django.utils.functional import Promise
  27 from django.utils.encoding import force_unicode
  28 from django.utils.http import urlquote_plus
  29 from django.views.decorators import cache
  30 from django.utils.translation import ugettext as _
  31 from django.views.generic.list_detail import object_list
  32
  33 from catalogue import models
  34 from catalogue import forms
  35 from catalogue.utils import split_tags
  36 from newtagging import views as newtagging_views
  37
  38
  39 staff_required = user_passes_test(lambda user: user.is_staff)
  40
  41
  42 class LazyEncoder(simplejson.JSONEncoder):
  43     def default(self, obj):
  44         if isinstance(obj, Promise):
  45             return force_unicode(obj)
  46         return obj
  47
  48 # shortcut for JSON reponses
  49 class JSONResponse(HttpResponse):
  50     def __init__(self, data={}, callback=None, **kwargs):
  51         # get rid of mimetype
  52         kwargs.pop('mimetype', None)
  53         data = simplejson.dumps(data)
  54         if callback:
  55             data = callback + "(" + data + ");"
  56         super(JSONResponse, self).__init__(data, mimetype="application/json", **kwargs)
  57
  58
  59 def main_page(request):
  60     if request.user.is_authenticated():
  61         shelves = models.Tag.objects.filter(category='set', user=request.user)
  62         new_set_form = forms.NewSetForm()
  63
  64     tags = models.Tag.objects.exclude(category__in=('set', 'book'))
  65     for tag in tags:
  66         tag.count = tag.get_count()
  67     categories = split_tags(tags)
  68     fragment_tags = categories.get('theme', [])
  69
  70     form = forms.SearchForm()
  71     return render_to_response('catalogue/main_page.html', locals(),
  72         context_instance=RequestContext(request))
  73
  74
  75 def book_list(request):
  76     form = forms.SearchForm()
  77
  78     books_by_parent = {}
  79     for book in models.Book.objects.all().order_by('parent_number'):
  80         books_by_parent.setdefault(book.parent, []).append(book)
  81
  82     orphans = []
  83     books_by_author = SortedDict()
  84     books_nav = SortedDict()
  85     for tag in models.Tag.objects.filter(category='author'):
  86         books_by_author[tag] = []
  87         if books_nav.has_key(tag.sort_key[0]):
  88             books_nav[tag.sort_key[0]].append(tag)
  89         else:
  90             books_nav[tag.sort_key[0]] = [tag]
  91
  92     for book in books_by_parent[None]:
  93         authors = list(book.tags.filter(category='author'))
  94         if authors:
  95             for author in authors:
  96                 books_by_author[author].append(book)
  97         else:
  98             orphans.append(book)
  99
 100     return render_to_response('catalogue/book_list.html', locals(),
 101         context_instance=RequestContext(request))
 102
 103
 104 def differentiate_tags(request, tags, ambiguous_slugs):
 105     beginning = '/'.join(tag.url_chunk for tag in tags)
 106     unparsed = '/'.join(ambiguous_slugs[1:])
 107     options = []
 108     for tag in models.Tag.objects.exclude(category='book').filter(slug=ambiguous_slugs[0]):
 109         options.append({
 110             'url_args': '/'.join((beginning, tag.url_chunk, unparsed)).strip('/'),
 111             'tags': [tag]
 112         })
 113     return render_to_response('catalogue/differentiate_tags.html',
 114                 {'tags': tags, 'options': options, 'unparsed': ambiguous_slugs[1:]},
 115                 context_instance=RequestContext(request))
 116
 117
 118 def tagged_object_list(request, tags=''):
 119     try:
 120         tags = models.Tag.get_tag_list(tags)
 121     except models.Tag.DoesNotExist:
 122         raise Http404
 123     except models.Tag.MultipleObjectsReturned, e:
 124         return differentiate_tags(request, e.tags, e.ambiguous_slugs)
 125
 126     try:
 127         if len(tags) > settings.MAX_TAG_LIST:
 128             raise Http404
 129     except AttributeError:
 130         pass
 131
 132     if len([tag for tag in tags if tag.category == 'book']):
 133         raise Http404
 134
 135     theme_is_set = [tag for tag in tags if tag.category == 'theme']
 136     shelf_is_set = [tag for tag in tags if tag.category == 'set']
 137     only_shelf = shelf_is_set and len(tags) == 1
 138     only_my_shelf = only_shelf and request.user.is_authenticated() and request.user == tags[0].user
 139
 140     objects = only_author = pd_counter = None
 141     categories = {}
 142
 143     if theme_is_set:
 144         shelf_tags = [tag for tag in tags if tag.category == 'set']
 145         fragment_tags = [tag for tag in tags if tag.category != 'set']
 146         fragments = models.Fragment.tagged.with_all(fragment_tags)
 147
 148         if shelf_tags:
 149             books = models.Book.tagged.with_all(shelf_tags).order_by()
 150             l_tags = models.Tag.objects.filter(category='book', slug__in=[book.book_tag_slug() for book in books])
 151             fragments = models.Fragment.tagged.with_any(l_tags, fragments)
 152
 153         # newtagging goes crazy if we just try:
 154         #related_tags = models.Tag.objects.usage_for_queryset(fragments, counts=True,
 155         #                    extra={'where': ["catalogue_tag.category != 'book'"]})
 156         fragment_keys = [fragment.pk for fragment in fragments]
 157         if fragment_keys:
 158             related_tags = models.Fragment.tags.usage(counts=True,
 159                                 filters={'pk__in': fragment_keys},
 160                                 extra={'where': ["catalogue_tag.category != 'book'"]})
 161             related_tags = (tag for tag in related_tags if tag not in fragment_tags)
 162             categories = split_tags(related_tags)
 163
 164             objects = fragments
 165     else:
 166         # get relevant books and their tags
 167         objects = models.Book.tagged.with_all(tags)
 168         if not shelf_is_set:
 169             # eliminate descendants
 170             l_tags = models.Tag.objects.filter(category='book', slug__in=[book.book_tag_slug() for book in objects])
 171             descendants_keys = [book.pk for book in models.Book.tagged.with_any(l_tags)]
 172             if descendants_keys:
 173                 objects = objects.exclude(pk__in=descendants_keys)
 174
 175         # get related tags from `tag_counter` and `theme_counter`
 176         related_counts = {}
 177         tags_pks = [tag.pk for tag in tags]
 178         for book in objects:
 179             for tag_pk, value in itertools.chain(book.tag_counter.iteritems(), book.theme_counter.iteritems()):
 180                 if tag_pk in tags_pks:
 181                     continue
 182                 related_counts[tag_pk] = related_counts.get(tag_pk, 0) + value
 183         related_tags = models.Tag.objects.filter(pk__in=related_counts.keys())
 184         related_tags = [tag for tag in related_tags if tag not in tags]
 185         for tag in related_tags:
 186             tag.count = related_counts[tag.pk]
 187
 188         categories = split_tags(related_tags)
 189         del related_tags
 190
 191     if not objects:
 192         only_author = len(tags) == 1 and tags[0].category == 'author'
 193         pd_counter = only_author and tags[0].goes_to_pd()
 194         objects = models.Book.objects.none()
 195
 196     return object_list(
 197         request,
 198         objects,
 199         template_name='catalogue/tagged_object_list.html',
 200         extra_context={
 201             'categories': categories,
 202             'only_shelf': only_shelf,
 203             'only_author': only_author,
 204             'pd_counter': pd_counter,
 205             'only_my_shelf': only_my_shelf,
 206             'formats_form': forms.DownloadFormatsForm(),
 207
 208             'tags': tags,
 209         }
 210     )
 211
 212
 213 def book_fragments(request, book_slug, theme_slug):
 214     book = get_object_or_404(models.Book, slug=book_slug)
 215     book_tag = get_object_or_404(models.Tag, slug='l-' + book_slug, category='book')
 216     theme = get_object_or_404(models.Tag, slug=theme_slug, category='theme')
 217     fragments = models.Fragment.tagged.with_all([book_tag, theme])
 218
 219     form = forms.SearchForm()
 220     return render_to_response('catalogue/book_fragments.html', locals(),
 221         context_instance=RequestContext(request))
 222
 223
 224 def book_detail(request, slug):
 225     try:
 226         book = models.Book.objects.get(slug=slug)
 227     except models.Book.DoesNotExist:
 228         return book_stub_detail(request, slug)
 229
 230     book_tag = book.book_tag()
 231     tags = list(book.tags.filter(~Q(category='set')))
 232     categories = split_tags(tags)
 233     book_children = book.children.all().order_by('parent_number')
 234
 235     _book = book
 236     parents = []
 237     while _book.parent:
 238         parents.append(_book.parent)
 239         _book = _book.parent
 240     parents = reversed(parents)
 241
 242     theme_counter = book.theme_counter
 243     book_themes = models.Tag.objects.filter(pk__in=theme_counter.keys())
 244     for tag in book_themes:
 245         tag.count = theme_counter[tag.pk]
 246
 247     extra_info = book.get_extra_info_value()
 248
 249     form = forms.SearchForm()
 250     return render_to_response('catalogue/book_detail.html', locals(),
 251         context_instance=RequestContext(request))
 252
 253
 254 def book_stub_detail(request, slug):
 255     book = get_object_or_404(models.BookStub, slug=slug)
 256     pd_counter = book.pd
 257     form = forms.SearchForm()
 258
 259     return render_to_response('catalogue/book_stub_detail.html', locals(),
 260         context_instance=RequestContext(request))
 261
 262
 263 def book_text(request, slug):
 264     book = get_object_or_404(models.Book, slug=slug)
 265     if not book.has_html_file():
 266         raise Http404
 267     book_themes = {}
 268     for fragment in book.fragments.all():
 269         for theme in fragment.tags.filter(category='theme'):
 270             book_themes.setdefault(theme, []).append(fragment)
 271
 272     book_themes = book_themes.items()
 273     book_themes.sort(key=lambda s: s[0].sort_key)
 274     return render_to_response('catalogue/book_text.html', locals(),
 275         context_instance=RequestContext(request))
 276
 277
 278 # ==========
 279 # = Search =
 280 # ==========
 281
 282 def _no_diacritics_regexp(query):
 283     """ returns a regexp for searching for a query without diacritics
 284
 285     should be locale-aware """
 286     names = {
 287         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',
 288         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'
 289         }
 290     def repl(m):
 291         l = m.group()
 292         return u"(%s)" % '|'.join(names[l])
 293     return re.sub(u'[%s]' % (u''.join(names.keys())), repl, query)
 294
 295 def unicode_re_escape(query):
 296     """ Unicode-friendly version of re.escape """
 297     return re.sub('(?u)(\W)', r'\\\1', query)
 298
 299 def _word_starts_with(name, prefix):
 300     """returns a Q object getting models having `name` contain a word
 301     starting with `prefix`
 302
 303     We define word characters as alphanumeric and underscore, like in JS.
 304
 305     Works for MySQL, PostgreSQL, Oracle.
 306     For SQLite, _sqlite* version is substituted for this.
 307     """
 308     kwargs = {}
 309
 310     prefix = _no_diacritics_regexp(unicode_re_escape(prefix))
 311     # can't use [[:<:]] (word start),
 312     # but we want both `xy` and `(xy` to catch `(xyz)`
 313     kwargs['%s__iregex' % name] = u"(^|[^[:alnum:]_])%s" % prefix
 314
 315     return Q(**kwargs)
 316
 317
 318 def _sqlite_word_starts_with(name, prefix):
 319     """ version of _word_starts_with for SQLite
 320
 321     SQLite in Django uses Python re module
 322     """
 323     kwargs = {}
 324     prefix = _no_diacritics_regexp(unicode_re_escape(prefix))
 325     kwargs['%s__iregex' % name] = ur"(^|(?<=[^\wąćęłńóśźżĄĆĘŁŃÓŚŹŻ]))%s" % prefix
 326     return Q(**kwargs)
 327
 328
 329 if settings.DATABASE_ENGINE == 'sqlite3':
 330     _word_starts_with = _sqlite_word_starts_with
 331
 332
 333 def _tags_starting_with(prefix, user=None):
 334     prefix = prefix.lower()
 335     book_stubs = models.BookStub.objects.filter(_word_starts_with('title', prefix))
 336     books = models.Book.objects.filter(_word_starts_with('title', prefix))
 337     book_stubs = filter(lambda x: x not in books, book_stubs)
 338     tags = models.Tag.objects.filter(_word_starts_with('name', prefix))
 339     if user and user.is_authenticated():
 340         tags = tags.filter(~Q(category='book') & (~Q(category='set') | Q(user=user)))
 341     else:
 342         tags = tags.filter(~Q(category='book') & ~Q(category='set'))
 343     return list(books) + list(tags) + list(book_stubs)
 344
 345
 346 def _get_result_link(match, tag_list):
 347     if isinstance(match, models.Book) or isinstance(match, models.BookStub):
 348         return match.get_absolute_url()
 349     else:
 350         return reverse('catalogue.views.tagged_object_list',
 351             kwargs={'tags': '/'.join(tag.url_chunk for tag in tag_list + [match])}
 352         )
 353
 354 def _get_result_type(match):
 355     if isinstance(match, models.Book) or isinstance(match, models.BookStub):
 356         type = 'book'
 357     else:
 358         type = match.category
 359     return type
 360
 361
 362
 363 def find_best_matches(query, user=None):
 364     """ Finds a Book, Tag or Bookstub best matching a query.
 365
 366     Returns a with:
 367       - zero elements when nothing is found,
 368       - one element when a best result is found,
 369       - more then one element on multiple exact matches
 370
 371     Raises a ValueError on too short a query.
 372     """
 373
 374     query = query.lower()
 375     if len(query) < 2:
 376         raise ValueError("query must have at least two characters")
 377
 378     result = tuple(_tags_starting_with(query, user))
 379     exact_matches = tuple(res for res in result if res.name.lower() == query)
 380     if exact_matches:
 381         return exact_matches
 382     else:
 383         return result[:1]
 384
 385
 386 def search(request):
 387     tags = request.GET.get('tags', '')
 388     prefix = request.GET.get('q', '')
 389
 390     try:
 391         tag_list = models.Tag.get_tag_list(tags)
 392     except:
 393         tag_list = []
 394
 395     try:
 396         result = find_best_matches(prefix, request.user)
 397     except ValueError:
 398         return render_to_response('catalogue/search_too_short.html', {'tags':tag_list, 'prefix':prefix},
 399             context_instance=RequestContext(request))
 400
 401     if len(result) == 1:
 402         return HttpResponseRedirect(_get_result_link(result[0], tag_list))
 403     elif len(result) > 1:
 404         return render_to_response('catalogue/search_multiple_hits.html',
 405             {'tags':tag_list, 'prefix':prefix, 'results':((x, _get_result_link(x, tag_list), _get_result_type(x)) for x in result)},
 406             context_instance=RequestContext(request))
 407     else:
 408         return render_to_response('catalogue/search_no_hits.html', {'tags':tag_list, 'prefix':prefix},
 409             context_instance=RequestContext(request))
 410
 411
 412 def tags_starting_with(request):
 413     prefix = request.GET.get('q', '')
 414     # Prefix must have at least 2 characters
 415     if len(prefix) < 2:
 416         return HttpResponse('')
 417     tags_list = []
 418     result = ""
 419     for tag in _tags_starting_with(prefix, request.user):
 420         if not tag.name in tags_list:
 421             result += "\n" + tag.name
 422             tags_list.append(tag.name)
 423     return HttpResponse(result)
 424
 425 def json_tags_starting_with(request, callback=None):
 426     # Callback for JSONP
 427     prefix = request.GET.get('q', '')
 428     callback = request.GET.get('callback', '')
 429     # Prefix must have at least 2 characters
 430     if len(prefix) < 2:
 431         return HttpResponse('')
 432     tags_list = []
 433     result = ""
 434     for tag in _tags_starting_with(prefix, request.user):
 435         if not tag.name in tags_list:
 436             result += "\n" + tag.name
 437             tags_list.append(tag.name)
 438     dict_result = {"matches": tags_list}
 439     return JSONResponse(dict_result, callback)
 440
 441 # ====================
 442 # = Shelf management =
 443 # ====================
 444 @login_required
 445 @cache.never_cache
 446 def user_shelves(request):
 447     shelves = models.Tag.objects.filter(category='set', user=request.user)
 448     new_set_form = forms.NewSetForm()
 449     return render_to_response('catalogue/user_shelves.html', locals(),
 450             context_instance=RequestContext(request))
 451
 452 @cache.never_cache
 453 def book_sets(request, slug):
 454     book = get_object_or_404(models.Book, slug=slug)
 455     user_sets = models.Tag.objects.filter(category='set', user=request.user)
 456     book_sets = book.tags.filter(category='set', user=request.user)
 457
 458     if not request.user.is_authenticated():
 459         return HttpResponse(_('<p>To maintain your shelves you need to be logged in.</p>'))
 460
 461     if request.method == 'POST':
 462         form = forms.ObjectSetsForm(book, request.user, request.POST)
 463         if form.is_valid():
 464             old_shelves = list(book.tags.filter(category='set'))
 465             new_shelves = [models.Tag.objects.get(pk=id) for id in form.cleaned_data['set_ids']]
 466
 467             for shelf in [shelf for shelf in old_shelves if shelf not in new_shelves]:
 468                 shelf.book_count = None
 469                 shelf.save()
 470
 471             for shelf in [shelf for shelf in new_shelves if shelf not in old_shelves]:
 472                 shelf.book_count = None
 473                 shelf.save()
 474
 475             book.tags = new_shelves + list(book.tags.filter(~Q(category='set') | ~Q(user=request.user)))
 476             if request.is_ajax():
 477                 return HttpResponse(_('<p>Shelves were sucessfully saved.</p>'))
 478             else:
 479                 return HttpResponseRedirect('/')
 480     else:
 481         form = forms.ObjectSetsForm(book, request.user)
 482         new_set_form = forms.NewSetForm()
 483
 484     return render_to_response('catalogue/book_sets.html', locals(),
 485         context_instance=RequestContext(request))
 486
 487
 488 @login_required
 489 @require_POST
 490 @cache.never_cache
 491 def remove_from_shelf(request, shelf, book):
 492     book = get_object_or_404(models.Book, slug=book)
 493     shelf = get_object_or_404(models.Tag, slug=shelf, category='set', user=request.user)
 494
 495     if shelf in book.tags:
 496         models.Tag.objects.remove_tag(book, shelf)
 497
 498         shelf.book_count = None
 499         shelf.save()
 500
 501         return HttpResponse(_('Book was successfully removed from the shelf'))
 502     else:
 503         return HttpResponse(_('This book is not on the shelf'))
 504
 505
 506 def collect_books(books):
 507     """
 508     Returns all real books in collection.
 509     """
 510     result = []
 511     for book in books:
 512         if len(book.children.all()) == 0:
 513             result.append(book)
 514         else:
 515             result += collect_books(book.children.all())
 516     return result
 517
 518
 519 @cache.never_cache
 520 def download_shelf(request, slug):
 521     """"
 522     Create a ZIP archive on disk and transmit it in chunks of 8KB,
 523     without loading the whole file into memory. A similar approach can
 524     be used for large dynamic PDF files.
 525     """
 526     shelf = get_object_or_404(models.Tag, slug=slug, category='set')
 527
 528     formats = []
 529     form = forms.DownloadFormatsForm(request.GET)
 530     if form.is_valid():
 531         formats = form.cleaned_data['formats']
 532     if len(formats) == 0:
 533         formats = ['pdf', 'epub', 'odt', 'txt', 'mp3', 'ogg']
 534
 535     # Create a ZIP archive
 536     temp = tempfile.TemporaryFile()
 537     archive = zipfile.ZipFile(temp, 'w')
 538
 539     already = set()
 540     for book in collect_books(models.Book.tagged.with_all(shelf)):
 541         if 'pdf' in formats and book.pdf_file:
 542             filename = book.pdf_file.path
 543             archive.write(filename, str('%s.pdf' % book.slug))
 544         if book.root_ancestor not in already and 'epub' in formats and book.root_ancestor.epub_file:
 545             filename = book.root_ancestor.epub_file.path
 546             archive.write(filename, str('%s.epub' % book.root_ancestor.slug))
 547             already.add(book.root_ancestor)
 548         if 'odt' in formats and book.odt_file:
 549             filename = book.odt_file.path
 550             archive.write(filename, str('%s.odt' % book.slug))
 551         if 'txt' in formats and book.txt_file:
 552             filename = book.txt_file.path
 553             archive.write(filename, str('%s.txt' % book.slug))
 554         if 'mp3' in formats and book.mp3_file:
 555             filename = book.mp3_file.path
 556             archive.write(filename, str('%s.mp3' % book.slug))
 557         if 'ogg' in formats and book.ogg_file:
 558             filename = book.ogg_file.path
 559             archive.write(filename, str('%s.ogg' % book.slug))
 560     archive.close()
 561
 562     response = HttpResponse(content_type='application/zip', mimetype='application/x-zip-compressed')
 563     response['Content-Disposition'] = 'attachment; filename=%s.zip' % shelf.sort_key
 564     response['Content-Length'] = temp.tell()
 565
 566     temp.seek(0)
 567     response.write(temp.read())
 568     return response
 569
 570
 571 @cache.never_cache
 572 def shelf_book_formats(request, shelf):
 573     """"
 574     Returns a list of formats of books in shelf.
 575     """
 576     shelf = get_object_or_404(models.Tag, slug=shelf, category='set')
 577
 578     formats = {'pdf': False, 'epub': False, 'odt': False, 'txt': False, 'mp3': False, 'ogg': False}
 579
 580     for book in collect_books(models.Book.tagged.with_all(shelf)):
 581         if book.pdf_file:
 582             formats['pdf'] = True
 583         if book.root_ancestor.epub_file:
 584             formats['epub'] = True
 585         if book.odt_file:
 586             formats['odt'] = True
 587         if book.txt_file:
 588             formats['txt'] = True
 589         if book.mp3_file:
 590             formats['mp3'] = True
 591         if book.ogg_file:
 592             formats['ogg'] = True
 593
 594     return HttpResponse(LazyEncoder().encode(formats))
 595
 596
 597 @login_required
 598 @require_POST
 599 @cache.never_cache
 600 def new_set(request):
 601     new_set_form = forms.NewSetForm(request.POST)
 602     if new_set_form.is_valid():
 603         new_set = new_set_form.save(request.user)
 604
 605         if request.is_ajax():
 606             return HttpResponse(_('<p>Shelf <strong>%s</strong> was successfully created</p>') % new_set)
 607         else:
 608             return HttpResponseRedirect('/')
 609
 610     return HttpResponseRedirect('/')
 611
 612
 613 @login_required
 614 @require_POST
 615 @cache.never_cache
 616 def delete_shelf(request, slug):
 617     user_set = get_object_or_404(models.Tag, slug=slug, category='set', user=request.user)
 618     user_set.delete()
 619
 620     if request.is_ajax():
 621         return HttpResponse(_('<p>Shelf <strong>%s</strong> was successfully removed</p>') % user_set.name)
 622     else:
 623         return HttpResponseRedirect('/')
 624
 625
 626 # ==================
 627 # = Authentication =
 628 # ==================
 629 @require_POST
 630 @cache.never_cache
 631 def login(request):
 632     form = AuthenticationForm(data=request.POST, prefix='login')
 633     if form.is_valid():
 634         auth.login(request, form.get_user())
 635         response_data = {'success': True, 'errors': {}}
 636     else:
 637         response_data = {'success': False, 'errors': form.errors}
 638     return HttpResponse(LazyEncoder(ensure_ascii=False).encode(response_data))
 639
 640
 641 @require_POST
 642 @cache.never_cache
 643 def register(request):
 644     registration_form = UserCreationForm(request.POST, prefix='registration')
 645     if registration_form.is_valid():
 646         user = registration_form.save()
 647         user = auth.authenticate(
 648             username=registration_form.cleaned_data['username'],
 649             password=registration_form.cleaned_data['password1']
 650         )
 651         auth.login(request, user)
 652         response_data = {'success': True, 'errors': {}}
 653     else:
 654         response_data = {'success': False, 'errors': registration_form.errors}
 655     return HttpResponse(LazyEncoder(ensure_ascii=False).encode(response_data))
 656
 657
 658 @cache.never_cache
 659 def logout_then_redirect(request):
 660     auth.logout(request)
 661     return HttpResponseRedirect(urlquote_plus(request.GET.get('next', '/'), safe='/?='))
 662
 663
 664
 665 # =========
 666 # = Admin =
 667 # =========
 668 @login_required
 669 @staff_required
 670 def import_book(request):
 671     """docstring for import_book"""
 672     book_import_form = forms.BookImportForm(request.POST, request.FILES)
 673     if book_import_form.is_valid():
 674         try:
 675             book_import_form.save()
 676         except:
 677             info = sys.exc_info()
 678             exception = pprint.pformat(info[1])
 679             tb = '\n'.join(traceback.format_tb(info[2]))
 680             return HttpResponse(_("An error occurred: %(exception)s\n\n%(tb)s") % {'exception':exception, 'tb':tb}, mimetype='text/plain')
 681         return HttpResponse(_("Book imported successfully"))
 682     else:
 683         return HttpResponse(_("Error importing file: %r") % book_import_form.errors)
 684
 685
 686
 687 def clock(request):
 688     """ Provides server time for jquery.countdown,
 689     in a format suitable for Date.parse()
 690     """
 691     from datetime import datetime
 692     return HttpResponse(datetime.now().strftime('%Y/%m/%d %H:%M:%S'))