Ticket #6285: columns_rows_filters.diff

django/template/defaultfilters.py

@@ -633 +633 @@
 unordered_list.is_safe = True
 unordered_list.needs_autoescape = True
 
+def columns(thelist, n):
+    """
+    Breaks a list into ``n`` number of columns, filling up each column to the 
+    maximum equal length possible. This filter will always return ``n`` 
+    columns, even if some are empty.
+
+    Usage::
+
+        {% for item_column in item_list|columns:3 %}
+        <li class="column">
+            <ul>
+                {% for item in item_column %}
+                <li><a href="#">{{ item }}</a></li>
+                {% endfor %}
+            </ul>
+        </li>
+        {% endfor %}
+
+    """
+    try:
+        n = int(n)
+        thelist = list(thelist)
+    except (ValueError, TypeError):
+        return [thelist]
+
+    list_len = len(thelist)
+    split = list_len // n
+
+    if list_len % n != 0:
+        split += 1
+
+    return [thelist[split*i:split*(i+1)] for i in range(n)]
+
+def rows(thelist, n):
+    """
+    Breaks a list into rows with a maximum number of ``n`` elements in each.
+
+    Usage::
+
+        {% for item_row in item_list|rows:4 %}
+        <li class="row">
+            <ul>
+                {% for item in item_row %}
+                <li><a href="#">{{ item }}</a></li>
+                {% endfor %}
+            </ul>
+        </li>
+        {% endfor %}
+
+    """
+    try:
+        n = int(n)
+        thelist = list(thelist)
+    except (ValueError, TypeError):
+        return [thelist]
+
+    newlists = [list() for i in range(int(ceil(len(thelist) / float(n))))]
+
+    for i, val in enumerate(thelist):
+        newlists[i/n].append(val)
+
+    return newlists
+
 ###################
 # INTEGERS        #
 ###################
@@ -896 +959 @@
 register.filter(truncatewords)
 register.filter(truncatewords_html)
 register.filter(unordered_list)
+register.filter(columns)
+register.filter(rows)
 register.filter(upper)
 register.filter(urlencode)
 register.filter(urlize)