From ec97bc7919a2416fca64a8137806616016a882b8 Mon Sep 17 00:00:00 2001
From: Martin Trigaux <mat@odoo.com>
Date: Tue, 10 Nov 2015 10:38:53 +0100
Subject: [PATCH] Language switcher

---
 _extensions/odoo/layout.html |  8 ++++----
 conf.py                      | 31 +++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/_extensions/odoo/layout.html b/_extensions/odoo/layout.html
index 1460506ab..39e8ec004 100644
--- a/_extensions/odoo/layout.html
+++ b/_extensions/odoo/layout.html
@@ -83,14 +83,14 @@
       </div>
 
       <nav class="collapse navbar-collapse navbar-main navbar-right" role="navigation">
-        {% if versions %}
+        {% if languages %}
           <ul class="navbar-nav navbar-right nav">
-            <li class="versions">
+            <li class="languages">
               <a class="dropdown-toggle" data-toggle="dropdown">
-                {{ version }} <span class="caret"></span>
+                {{ language }} <span class="caret"></span>
               </a>
               <ul class="dropdown-menu" role="menu">
-                {% for name, url in versions %}
+                {% for name, url in languages %}
                   <li><a href="{{ url }}">{{ name }}</a></li>
                 {% endfor %}
               </ul>
diff --git a/conf.py b/conf.py
index a1d4c58d9..1ad6d3fb7 100644
--- a/conf.py
+++ b/conf.py
@@ -286,9 +286,14 @@ def setup(app):
     app.add_javascript('inventory.js');
     app.add_javascript('coa-valuation.js')
 
+    app.add_config_value('canonical_root', None, 'env')
+
     app.connect('html-page-context', analytics)
     app.add_config_value('google_analytics_key', '', 'env')
 
+    app.connect('html-page-context', localize)
+    app.add_config_value('languages', '', 'env')
+
     app.connect('doctree-resolved', tag_toctrees)
 
 def analytics(app, pagename, templatename, context, doctree):
@@ -314,3 +319,29 @@ def tag_toctrees(app, doctree, docname):
         return
 
     app.env.metadata[docname]['has-toc'] = True
+
+
+def localize(app, pagename, templatename, context, doctree):
+    """ Adds a language switcher below the menu, requires ``canonical_root``
+    and ``languages`` (an ordered, space-separated lists of all possible
+    languages).
+    """
+    if not (app.config.canonical_root and app.config.languages):
+        return
+
+    current_lang = app.config.language or 'en'
+    context['language'] = current_lang.upper()
+    context['languages'] = [
+        (la.upper(), _build_url(app.config.canonical_root, la, pagename))
+        for la in app.config.languages.split(',')
+        if la != current_lang
+    ]
+
+
+def _build_url(root, branch, pagename):
+    return "{canonical_url}{canonical_branch}/{canonical_page}".format(
+        canonical_url=root,
+        canonical_branch=branch,
+        canonical_page=(pagename + '.html').replace('index.html', '')
+                                           .replace('index/', ''),
+    )