1 files changed, 50 insertions, 0 deletions
diff --git a/grc/core/params/template_arg.py b/grc/core/params/template_arg.py
new file mode 100644
index 0000000000..5c8c610b4f
--- /dev/null
+++ b/grc/core/params/template_arg.py
@@ -0,0 +1,50 @@
+# Copyright 2008-2017 Free Software Foundation, Inc.
+# This file is part of GNU Radio
+#
+# GNU Radio Companion is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# GNU Radio Companion 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+
+from __future__ import absolute_import
+
+
+class TemplateArg(str):
+    """
+    A cheetah template argument created from a param.
+    The str of this class evaluates to the param's to code method.
+    The use of this class as a dictionary (enum only) will reveal the enum opts.
+    The __call__ or () method can return the param evaluated to a raw python data type.
+    """
+
+    def __new__(cls, param):
+        value = param.to_code()
+        instance = str.__new__(cls, value)
+        setattr(instance, '_param', param)
+        return instance
+
+    def __getitem__(self, item):
+        return str(self._param.get_opt(item)) if self._param.is_enum() else NotImplemented
+
+    def __getattr__(self, item):
+        if not self._param.is_enum():
+            raise AttributeError()
+        try:
+            return str(self._param.get_opt(item))
+        except KeyError:
+            raise AttributeError()
+
+    def __str__(self):
+        return str(self._param.to_code())
+
+    def __call__(self):
+        return self._param.get_evaluated()