override gettext "_" behaviour to also support interpolation

1 files changed, 37 insertions, 0 deletions

diff --git a/lib/i18n_fixes.rb b/lib/i18n_fixes.rb
new file mode 100644
index 000000000..9d7a999dd
--- /dev/null
+++ b/lib/i18n_fixes.rb
@@ -0,0 +1,37 @@
+# override behaviour in fast_gettext/translation.rb
+# so that we can interpolate our translation strings nicely
+
+def _(key, options = {})
+  translation = FastGettext._(key) || key
+  gettext_interpolate(translation, options)
+end
+
+INTERPOLATION_RESERVED_KEYS = %w(scope default)
+MATCH = /(\\\\)?\{\{([^\}]+)\}\}/
+
+def gettext_interpolate(string, values)
+  return string unless string.is_a?(String)
+  if values.is_a?(Hash)
+    string.gsub(MATCH) do
+      escaped, pattern, key = $1, $2, $2.to_sym
+      
+      if escaped
+        pattern
+      elsif INTERPOLATION_RESERVED_KEYS.include?(pattern)
+        raise ReservedInterpolationKey.new(pattern, string)
+      elsif !values.include?(key)
+        raise MissingInterpolationArgument.new(pattern, string)
+      else
+        values[key].to_s
+      end
+    end
+  else
+    reserved_keys = if defined?(I18n::RESERVED_KEYS) # rails 3+
+                      I18n::RESERVED_KEYS
+                    else
+                      I18n::Backend::Base::RESERVED_KEYS
+                    end
+
+    string % values.except(*reserved_keys)
+  end
+end