Merge pull request #4 from avaris/master

Add Neighbor Articles plugin

pelicanext/neighbors/README.rst

@@ -0,0 +1,44 @@
+Neighbor Articles Plugin for Pelican
+====================================
+
+This plugin adds ``next_article`` (newer) and ``prev_article`` (older) 
+variables to the article's context
+
+Installation
+------------
+To enable, ensure that ``neighbors.py`` is in somewhere you can ``import``.
+Then use the following in your `settings`::
+
+    PLUGINS = ["neighbors"]
+
+Or you can put the plugin in ``plugins`` folder in pelican installation. You 
+can find the location by typing::
+
+    python -c 'import pelican.plugins as p, os; print os.path.dirname(p.__file__)'
+
+Once you get the folder, copy the ``neighbors.py`` there and use the following
+in your settings::
+
+    PLUGINS = ["pelican.plugins.neighbors"]
+
+Usage
+-----
+
+.. code-block:: html+jinja
+
+    <ul>
+    {% if article.prev_article %}
+        <li>
+            <a href="{{ SITEURL }}/{{ article.prev_article.url}}">
+                {{ article.prev_article.title }}
+            </a>
+        </li>
+    {% endif %}
+    {% if article.next_article %}
+        <li>
+            <a href="{{ SITEURL }}/{{ article.next_article.url}}">
+                {{ article.next_article.title }}
+            </a>
+        </li>
+    {% endif %}
+    </ul>

pelicanext/neighbors/neighbors.py

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+# -*- coding: utf-8 -*-
+"""
+Neighbor Articles Plugin for Pelican
+====================================
+
+This plugin adds ``next_article`` (newer) and ``prev_article`` (older) 
+variables to the article's context
+"""
+
+from pelican import signals
+
+def iter3(seq):
+    it = iter(seq)
+    nxt = None
+    cur = next(it)
+    for prv in it:
+        yield nxt, cur, prv
+        nxt, cur = cur, prv
+    yield nxt, cur, None
+
+def neighbors(generator):
+    for nxt, cur, prv in iter3(generator.articles):
+        cur.next_article = nxt
+        cur.prev_article = prv
+
+def register():
+    signals.article_generator_finalized.connect(neighbors)