adds previous and next links in the sidebar

Feature #401 - previous/next navigation on media pages
* media.html includes a new prev_next.html template containing the links
* prev_next.html calls functions added to the media model to retrieve
  the appropriate objects from the database, formatted with urlgen
* a small change to util.py brings ASCENDING into the mix

2 files changed, 46 insertions, 0 deletions

diff --git a/mediagoblin/templates/mediagoblin/user_pages/media.html b/mediagoblin/templates/mediagoblin/user_pages/media.html
index 3cebe2f9..6159a853 100644
--- a/mediagoblin/templates/mediagoblin/user_pages/media.html
+++ b/mediagoblin/templates/mediagoblin/user_pages/media.html
@@ -96,6 +96,7 @@
 
     <div class="grid_4 omega media_sidebar">
       <p>This is a sidebar! Yay!</p>
+      {% include "mediagoblin/utils/prev_next.html" %}
     </div>
   {% else %}
   <p>Sorry, no such media found.<p/>
diff --git a/mediagoblin/templates/mediagoblin/utils/prev_next.html b/mediagoblin/templates/mediagoblin/utils/prev_next.html
new file mode 100644
index 00000000..e054ed23
--- /dev/null
+++ b/mediagoblin/templates/mediagoblin/utils/prev_next.html
@@ -0,0 +1,45 @@
+{#
+# GNU MediaGoblin -- federated, autonomous media hosting
+# Copyright (C) 2011 Free Software Foundation, Inc
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#}
+
+{# Provide navigation links to neighboring media entries, if possible #}
+{% set prev_entry_url = media.url_to_prev(request.urlgen) %}
+{% set next_entry_url = media.url_to_next(request.urlgen) %}
+
+<div>
+  {# There are no previous entries for the very first media entry #}
+  {% if prev_entry_url %}
+    <a href="{{ prev_entry_url }}">
+      {# TODO - insert 'Previous' and 'X' image sources #}
+      Previous 
+    </a>
+  {% else %}
+    {# This is the first entry. display greyed-out 'previous' image #}
+    X 
+  {% endif %}
+
+  {# Likewise, this could be the very last media entry #}
+  {% if next_entry_url %}
+    <a href="{{ next_entry_url }}">
+      {# TODO - insert 'Next' and 'X' image sources #}
+       Next
+    </a>
+  {% else %}
+    {# This is the last entry. display greyed-out 'next' image #}
+     X
+  {% endif %}
+</div>