Add a setting to limit feeds to a max number of items.

This adds FEED_MAX_ITEMS, which dictates the maximum number of items allowed in a feed.

pelican/settings.py

@@ -15,6 +15,7 @@ _DEFAULT_CONFIG = {'PATH': None,
                    'FEED': 'feeds/all.atom.xml',
                    'CATEGORY_FEED': 'feeds/%s.atom.xml',
                    'TRANSLATION_FEED': 'feeds/all-%s.atom.xml',
+                   'FEED_MAX_ITEMS': '',
                    'SITENAME': 'A Pelican Blog',
                    'DISPLAY_PAGES_ON_MENU': True,
                    'PDF_GENERATOR': False,

pelican/writers.py

@@ -58,8 +58,11 @@ class Writer(object):
 
             feed = self._create_new_feed(feed_type, context)
 
-            for item in elements:
-                self._add_item_to_the_feed(feed, item)
+            max_items = len(elements)
+            if self.settings['FEED_MAX_ITEMS']:
+                max_items = min(self.settings['FEED_MAX_ITEMS'], max_items)
+            for i in xrange(max_items):
+                self._add_item_to_the_feed(feed, elements[i])
 
             if filename:
                 complete_path = os.path.join(self.output_path, filename)