initial OPDS catalogue support
authorRadek Czajka <radoslaw.czajka@nowoczesnapolska.org.pl>
Mon, 20 Sep 2010 13:08:39 +0000 (15:08 +0200)
committerRadek Czajka <radoslaw.czajka@nowoczesnapolska.org.pl>
Mon, 20 Sep 2010 13:08:39 +0000 (15:08 +0200)
apps/catalogue/feeds.py [new file with mode: 0644]
apps/catalogue/urls.py

diff --git a/apps/catalogue/feeds.py b/apps/catalogue/feeds.py
new file mode 100644 (file)
index 0000000..0d0bf77
--- /dev/null
@@ -0,0 +1,219 @@
+# -*- coding: utf-8 -*-
+# This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
+#
+from base64 import b64encode
+import os.path
+
+from django.contrib.syndication.views import Feed
+from django.core.urlresolvers import reverse
+from django.shortcuts import get_object_or_404
+from django.utils.feedgenerator import Atom1Feed
+from django.conf import settings
+from django.http import Http404
+from django.contrib.sites.models import Site
+
+from catalogue.models import Book, Tag
+
+
+_root_feeds = (
+       {u"category": u"author", u"title": u"Autorzy", u"description": u"Utwory wg autorów"},
+       {u"category": u"kind", u"title": u"Rodzaje", u"description": u"Utwory wg rodzajów"},
+       {u"category": u"genre", u"title": u"Gatunki", u"description": u"Utwory wg gatunków"},
+       {u"category": u"epoch", u"title": u"Epoki", u"description": u"Utwory wg epok"},
+)
+
+
+class OPDSFeed(Atom1Feed):
+    link_rel = u"subsection"
+    link_type = u"application/atom+xml"
+
+    try:
+        with open(os.path.join(settings.STATIC_ROOT, "img/book-par ent.png")) as f:
+            t = f.read()
+            _book_parent_img_size = len(t)
+            _book_parent_img = b64encode(t)
+    except:
+        _book_parent_img = _book_parent_img_size = ''
+
+    try:
+        with open(os.path.join(settings.STATIC_ROOT, "img/bo ok.png")) as f:
+            t = f.read()
+            _book_img_size = len(t)
+            _book_img = b64encode(t)
+    except:
+        _book_img = _book_img_size = ''
+
+    def add_root_elements(self, handler):
+        super(OPDSFeed, self).add_root_elements(handler)
+        handler.addQuickElement(u"link", u"", {u"href": reverse("opds_authors"), u"rel": u"start", u"type": u"application/atom+xml"})
+
+
+    def add_item_elements(self, handler, item):
+        """ modified from Atom1Feed.add_item_elements """
+        handler.addQuickElement(u"title", item['title'])
+
+        # add a OPDS Navigation link if there's no enclosure
+        if item['enclosure'] is None:
+            handler.addQuickElement(u"link", u"", {u"href": item['link'], u"rel": u"subsection", u"type": u"application/atom+xml"})
+            # add a "green book" icon
+            handler.addQuickElement(u"link", '',
+                {u"rel": u"http://opds-spec.org/thumbnail",
+                 u"href": u"data:image/png;base64,%s" % self._book_parent_img,
+                 u"length": unicode(self._book_parent_img_size),
+                 u"type": u"image/png"})
+        if item['pubdate'] is not None:
+            handler.addQuickElement(u"updated", rfc3339_date(item['pubdate']).decode('utf-8'))
+
+        # Author information.
+        if item['author_name'] is not None:
+            handler.startElement(u"author", {})
+            handler.addQuickElement(u"name", item['author_name'])
+            if item['author_email'] is not None:
+                handler.addQuickElement(u"email", item['author_email'])
+            if item['author_link'] is not None:
+                handler.addQuickElement(u"uri", item['author_link'])
+            handler.endElement(u"author")
+
+        # Unique ID.
+        if item['unique_id'] is not None:
+            unique_id = item['unique_id']
+        else:
+            unique_id = get_tag_uri(item['link'], item['pubdate'])
+        handler.addQuickElement(u"id", unique_id)
+
+        # Summary.
+        # OPDS needs type=text
+        if item['description'] is not None:
+            handler.addQuickElement(u"summary", item['description'], {u"type": u"text"})
+
+        # Enclosure as OPDS Acquisition Link
+        if item['enclosure'] is not None:
+            handler.addQuickElement(u"link", '',
+                {u"rel": u"http://opds-spec.org/acquisition",
+                 u"href": item['enclosure'].url,
+                 u"length": item['enclosure'].length,
+                 u"type": item['enclosure'].mime_type})
+            # add a "red book" icon
+            handler.addQuickElement(u"link", '',
+                {u"rel": u"http://opds-spec.org/thumbnail",
+                 u"href": u"data:image/png;base64,%s" % self._book_img,
+                 u"length": unicode(self._book_img_size),
+                 u"type": u"image/png"})
+
+        # Categories.
+        for cat in item['categories']:
+            handler.addQuickElement(u"category", u"", {u"term": cat})
+
+        # Rights.
+        if item['item_copyright'] is not None:
+            handler.addQuickElement(u"rights", item['item_copyright'])
+
+
+class RootFeed(Feed):
+    feed_type = OPDSFeed
+    title = u'Wolne Lektury'
+    link = u'http://www.wolnelektury.pl/'
+    description = u"Spis utworów na stronie http://WolneLektury.pl"
+    author_name = u"Wolne Lektury"
+    author_link = u"http://www.wolnelektury.pl/"
+
+    def items(self):
+        return _root_feeds
+
+    def item_title(self, item):
+        return item['title']
+
+    def item_link(self, item):
+        return reverse(u"opds_by_category", args=[item['category']])
+
+    def item_description(self, item):
+        return item['description']
+
+
+class ByCategoryFeed(Feed):
+    feed_type = OPDSFeed
+    link = u'http://www.wolnelektury.pl/'
+    description = u"Spis utworów na stronie http://WolneLektury.pl"
+    author_name = u"Wolne Lektury"
+    author_link = u"http://www.wolnelektury.pl/"
+
+    def get_object(self, request, category):
+        feed = [feed for feed in _root_feeds if feed['category']==category]
+        if feed:
+            feed = feed[0]
+        else:
+            raise Http404
+
+        return feed
+
+    def title(self, feed):
+        return feed['title']
+
+    def items(self, feed):
+        return (tag for tag in Tag.objects.filter(category=feed['category']) if tag.get_count() > 0)
+
+    def item_title(self, item):
+        return item.name
+
+    def item_link(self, item):
+        return reverse("opds_by_tag", args=[item.category, item.slug])
+
+    def item_description(self):
+        return u''
+
+
+class ByTagFeed(Feed):
+    feed_type = OPDSFeed
+    link = u'http://www.wolnelektury.pl/'
+    item_enclosure_mime_type = "application/epub+zip"
+    author_name = u"Wolne Lektury"
+    author_link = u"http://www.wolnelektury.pl/"
+
+    def link(self, tag):
+        return tag.get_absolute_url()
+
+    def title(self, tag):
+        return tag.name
+
+    def description(self, tag):
+        return u"Spis utworów na stronie http://WolneLektury.pl"
+
+    def get_object(self, request, category, slug):
+        return get_object_or_404(Tag, category=category, slug=slug)
+
+    def items(self, tag):
+        books = Book.tagged.with_any([tag])
+        l_tags = Tag.objects.filter(category='book', slug__in=[book.book_tag_slug() for book in books])
+        descendants_keys = [book.pk for book in Book.tagged.with_any(l_tags)]
+        if descendants_keys:
+            books = books.exclude(pk__in=descendants_keys)
+
+        return books
+
+    def item_title(self, book):
+        return book.title
+
+    def item_description(self):
+        return u''
+
+    def item_link(self, book):
+        return book.get_absolute_url()
+
+    def item_author_name(self, book):
+        try:
+            return book.tags.filter(category='author')[0].name
+        except KeyError:
+            return u''
+
+    def item_author_link(self, book):
+        try:
+            return book.tags.filter(category='author')[0].get_absolute_url()
+        except KeyError:
+            return u''
+
+    def item_enclosure_url(self, book):
+        return "http://%s%s" % (Site.objects.get_current().domain, book.epub_file.url)
+
+    def item_enclosure_length(self, book):
+        return book.epub_file.size
index 70d5fd8..ba9818d 100644 (file)
@@ -3,6 +3,7 @@
 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
 #
 from django.conf.urls.defaults import *
+from catalogue.feeds import RootFeed, ByCategoryFeed, ByTagFeed
 
 
 urlpatterns = patterns('catalogue.views',
@@ -22,6 +23,11 @@ urlpatterns = patterns('catalogue.views',
     # tools
     url(r'^zegar', 'clock', name='clock'),
 
+    # OPDS interface
+    url(r'^opds/$', RootFeed(), name="opds_authors"),
+    url(r'^opds/(?P<category>author|kind|genre|epoch|theme)/$', ByCategoryFeed(), name="opds_by_category"),
+    url(r'^opds/(?P<category>author|kind|genre|epoch|theme)/(?P<slug>[a-zA-Z0-9-]+)/$', ByTagFeed(), name="opds_by_tag"),
+
     # Public interface. Do not change this URLs.
     url(r'^lektura/(?P<slug>[a-zA-Z0-9-]+)\.html$', 'book_text', name='book_text'),
     url(r'^lektura/(?P<slug>[a-zA-Z0-9-]+)/$', 'book_detail', name='book_detail'),