generation of rss feed

1 files changed, 50 insertions, 0 deletions

diff --git a/watchnews/rss.py b/watchnews/rss.py
new file mode 100644
index 0000000..30510c2
--- /dev/null
+++ b/watchnews/rss.py
@@ -0,0 +1,50 @@
+from . import data
+from .web import Difftable
+
+
+from ll.xist import xsc, parse
+from ll.xist.ns import xml, rss20
+
+
+def rss():
+    versions = data.Version.raw("""\
+SELECT * 
+FROM version v
+WHERE EXISTS (SELECT 1 
+              FROM version v2
+              WHERE v2.id != v.id 
+                AND v2.item_id == v.item_id
+                AND v2.created_date < v.created_date)
+ORDER BY v.created_date DESC
+LIMIT 30""")
+
+    items = []
+    for to_version in versions:
+        from_version = data.Version.select() \
+            .where((data.Version.id != to_version.id) &
+                   (data.Version.item == to_version.item) &
+                   (data.Version.created_date < to_version.created_date)) \
+            .order_by(data.Version.created_date.desc()) \
+            .first()
+
+        difftable = Difftable(to_version, from_version,
+                              inline_style=True).string("utf-8")
+        items.append(rss20.item(
+            rss20.title(
+                "{} - {}".format(to_version.item.feed.title, to_version.title)),
+            rss20.author(to_version.authors),
+            rss20.pubDate(to_version.created_date.strftime(
+                "%a, %d %b %Y %T %z")),
+            rss20.guid("from={},to={}".format(from_version.id, to_version.id)),
+            rss20.link(to_version.url),
+            rss20.description(
+                xsc.Text(difftable)
+            )
+        ))
+    return xsc.Frag(xml.XML(), rss20.rss(
+        rss20.channel(
+            rss20.title("Watchnews change report"),
+            *items
+        )
+    )
+    ).string("utf-8")