+ def build_epub(self, remove_descendants=True):
+ """ (Re)builds the epub file.
+ If book has a parent, does nothing.
+ Unless remove_descendants is False, descendants' epubs are removed.
+ """
+
+ from StringIO import StringIO
+ from hashlib import sha1
+ from django.core.files.base import ContentFile
+ from librarian import DocProvider
+
+ class BookImportDocProvider(DocProvider):
+ """ used for joined EPUBs """
+
+ def __init__(self, book):
+ self.book = book
+
+ def by_slug(self, slug):
+ if slug == self.book.slug:
+ return self.book.xml_file
+ else:
+ return Book.objects.get(slug=slug).xml_file
+
+ if self.parent:
+ # don't need an epub
+ return
+
+ epub_file = StringIO()
+ try:
+ epub.transform(BookImportDocProvider(self), self.slug, epub_file)
+ self.epub_file.save('%s.epub' % self.slug, ContentFile(epub_file.getvalue()), save=False)
+ FileRecord(slug=self.slug, type='epub', sha1=sha1(epub_file.getvalue()).hexdigest()).save()
+ except NoDublinCore:
+ pass
+
+ if remove_descendants:
+ book_descendants = list(self.children.all())
+ while len(book_descendants) > 0:
+ child_book = book_descendants.pop(0)
+ if child_book.has_epub_file():
+ child_book.epub_file.delete()
+ book_descendants += list(child_book.children.all())
+
+