Merge pull request #3 from scholastica/sort-rss-feed

add sort_by field

README.md

@@ -33,5 +33,22 @@ Finally, this will produce two separate RSS feeds:
 
 Which is exactly what we need to support MailChimp's [RSS-to-Email](http://mailchimp.com/features/rss-to-email) feature!
 
+
+### Ordering
+
+You can limit and order by fields
+
+In the _config.yml add a `sort_by` key
+
+Example:
+
+    feed:
+      type: atom
+      limit: 0
+      sort_by:
+        field: date
+        direction: desc
+
+
 ### Technical details
 To accomplish this, we forked / hacked the [Hexo-Generator-Category-Feed](https://github.com/wmeints/hexo-generator-feed-per-category) plugin. For more information, including a diff showing exactly what we changed, see https://github.com/scholastica/hexo-generator-feed-per-category/commit/586a0a9e422b2ebdd5c1678535a14b326a87a3dd.

lib/generator.js

@@ -49,6 +49,11 @@ module.exports = function(locals) {
             posts = posts.limit(config.feed.limit);
         }
 
+        if(config.feed.sort_by) {
+          var direction = config.feed.sort_by.direction == 'asc' ? 1 : -1
+          posts = posts.sort(config.feed.sort_by.field, direction)
+        }
+
         var url = config.url;
         if (url[url.length - 1] !== '/') url += '/';