Added plugin for handling general-purpose session variables across tasks.

Supported methods: variable.get, variable.set, variable.unset

platypush/plugins/variable.py

@@ -0,0 +1,31 @@
+from platypush.message.response import Response
+from platypush.plugins import Plugin
+
+
+class VariablePlugin(Plugin):
+    """
+    This plugin allows you to manipulate context variables that can be
+    accessed across your tasks.
+    """
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._variables = {}
+
+    def get(self, name, default_value=None):
+        return Response(output={name: self._variables.get(name, default_value)})
+
+    def set(self, name, value):
+        self._variables[name] = value
+        return Response(output={'status':'ok'})
+
+    def unset(self, name):
+        if name in self._variables:
+            del self._variables[name]
+            return Response(output={'status':'ok'})
+        else:
+            return Response(output={'status':'not_found'})
+
+
+# vim:sw=4:ts=4:et:
+