From 1eef779e00a851a15d69f6530f2d70e80d7d128d Mon Sep 17 00:00:00 2001
From: Fabien Potencier <fabien.potencier@gmail.com>
Date: Fri, 13 Aug 2010 19:15:57 +0200
Subject: [PATCH] added a trans filter (closes #85)

---
 CHANGELOG                                   |    1 +
 doc/02-Twig-for-Template-Designers.markdown |    6 ++++++
 doc/06-Recipes.markdown                     |   20 ++++++++++++++++++++
 lib/Twig/Extension/I18n.php                 |   12 ++++++++++++
 4 files changed, 39 insertions(+), 0 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 295252e..30cea44 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -5,6 +5,7 @@ Backward incompatibilities:
  * the odd and even filters are now tests:
      {{ foo|odd }} must now be written {{ foo is(odd) }}
 
+ * added a "trans" filter
  * added "test" feature (accessible via the "is" operator)
  * removed the debug tag (should be done in an extension)
  * fixed trans tag when no vars are used in plural form
diff --git a/doc/02-Twig-for-Template-Designers.markdown b/doc/02-Twig-for-Template-Designers.markdown
index fa646db..2eefee4 100644
--- a/doc/02-Twig-for-Template-Designers.markdown
+++ b/doc/02-Twig-for-Template-Designers.markdown
@@ -881,6 +881,12 @@ The `plural` tag should provide the `count` used to select the right string.
 Within the translatable string, the special `count` variable always contain
 the count value (here the value of `apple_count`).
 
+Within an expression or in a tag, you can use the `trans` filter to translate
+simple strings or variables:
+
+    [twig]
+    {{ var|default(default_value|trans) }}
+
 Expressions
 -----------
 
diff --git a/doc/06-Recipes.markdown b/doc/06-Recipes.markdown
index e618a1f..1ef180f 100644
--- a/doc/06-Recipes.markdown
+++ b/doc/06-Recipes.markdown
@@ -243,3 +243,23 @@ Use the standard `xgettext` utility as you would have done with plain PHP
 code:
 
     xgettext --default-domain=messages -p ./locale --from-code=UTF-8 -n --omit-header -L PHP /tmp/cache/*.php
+
+Complex Translations within an Expression or Tag
+------------------------------------------------
+
+Translations can be done with both the `trans` tag and the `trans` filter. The
+filter is less powerful as it only works for simple variables or strings. For
+more complex scenario, like pluralization, you can use a two-step strategy:
+
+    [twig]
+    {# assign the translation to a temporary variable #}
+    {% set default_value %}
+        {% trans %}
+          Hey {{ name }}, I have one apple.
+        {% plural apple_count %}
+          Hey {{ name }}, I have {{ count }} apples.
+        {% endtrans %}
+    {% endset %}
+
+    {# use the temporary variable within an expression #}
+    {{ var|default(default_value|trans) }}
diff --git a/lib/Twig/Extension/I18n.php b/lib/Twig/Extension/I18n.php
index 0e22c24..d1d7a10 100644
--- a/lib/Twig/Extension/I18n.php
+++ b/lib/Twig/Extension/I18n.php
@@ -21,6 +21,18 @@ class Twig_Extension_I18n extends Twig_Extension
     }
 
     /**
+     * Returns a list of filters to add to the existing list.
+     *
+     * @return array An array of filters
+     */
+    public function getFilters()
+    {
+        return array(
+            'trans' => new Twig_Filter_Function('gettext'),
+        );
+    }
+
+    /**
      * Returns the name of the extension.
      *
      * @return string The extension name
-- 
1.7.2.5