Merge pull request #1348 from vjousse/davidmarble-page-order-by

Support ordering pages and articles when iterating in templates.

pelican/utils.py

@@ -440,7 +440,7 @@ def truncate_html_words(s, num, end_text='...'):
     return out
 
 
-def process_translations(content_list):
+def process_translations(content_list, order_by=None):
     """ Finds translation and returns them.
 
     Returns a tuple with two lists (index, translations).  Index list includes
@@ -450,6 +450,14 @@ def process_translations(content_list):
     the same slug have that metadata.
 
     For each content_list item, sets the 'translations' attribute.
+
+    order_by can be a string of an attribute or sorting function. If order_by
+    is defined, content will be ordered by that attribute or sorting function.
+    By default, content is ordered by slug.
+
+    Different content types can have default order_by attributes defined
+    in settings, e.g. PAGES_ORDER_BY='sort-order', in which case `sort-order`
+    should be a defined metadata attribute in each page.
     """
     content_list.sort(key=attrgetter('slug'))
     grouped_by_slugs = groupby(content_list, attrgetter('slug'))
@@ -495,6 +503,23 @@ def process_translations(content_list):
         translations.extend([x for x in items if x not in default_lang_items])
         for a in items:
             a.translations = [x for x in items if x != a]
+
+    if order_by:
+        if callable(order_by):
+            try:
+                index.sort(key=order_by)
+            except Exception:
+                logger.error('Error sorting with function {}'.format(order_by))
+        elif order_by == 'basename':
+            index.sort(key=lambda x: os.path.basename(x.source_path or ''))
+        elif order_by != 'slug':
+            try:
+                index.sort(key=attrgetter(order_by))
+            except AttributeError:
+                error_msg = ('There is no "{}" attribute in the item metadata.'
+                             'Defaulting to slug order.')
+                logger.warning(error_msg.format(order_by))
+
     return index, translations