def _chapter_next_previous(document, chapter, dir='next'):
'''Returns the next or previous data object from the OPF'''
toc = document.get_toc()
item = toc.find_item_by_id(chapter.idref)
if dir == 'next':
target_item = toc.find_next_item(item)
else:
target_item = toc.find_previous_item(item)
if target_item is None:
return None
object = get_file_by_item(target_item, document)
return object
def view(request, title, key, first=False, resume=False):
'''If we view just a document, we want to either see our last chapter,
or see the first item in the <opf:spine>, as required by the epub specification.'''
log.debug("Looking up title %s, key %s" % (title, key))
document = _get_document(request, title, key)
# If we got 'None' from get_document with an anonymous user, then prompt them
# to login; this is probably just a bookmark with an unauthenticated user
if document is None and request.user.is_anonymous():
return HttpResponseRedirect(reverse('user_signin'))
if not request.user.is_anonymous():
uprofile = request.user.get_profile()
last_chapter_read = document.get_last_chapter_read(request.user)
else:
last_chapter_read = None
uprofile = None
if resume and last_chapter_read is not None:
chapter = last_chapter_read
elif not first and uprofile and uprofile.open_to_last_chapter and last_chapter_read:
chapter = last_chapter_read
else:
try:
toc = document.get_toc()
first_item = toc.first_item()
chapter = get_file_by_item(first_item, document)
except InvalidEpubException:
# We got some kind of catastrophic error while trying to
# parse this document
message = _('There was a problem reading the metadata for this document.')
return view_chapter(request, title, key, None, message=message)
if chapter is None:
log.error('Could not find an item with the id of %s' % first_item)
raise Http404
if first:
log.debug("Forcing first chapter")
# Force an HTTP redirect so we get a clean URL but go to the correct chapter ID
return HttpResponseRedirect(reverse('view_chapter', kwargs={'title':document.safe_title(), 'key': document.id, 'chapter_id':chapter.filename}))
return view_chapter(request, title, key, None, chapter=chapter, document=document)