I don't see the field current_dep being added to the view.  If it isn't in the view, you can't use it in the domain.

Python knows the purposes of certain names (ex. built-in functions ). Other names are defined within the program (ex. variables). If Python encounters a name that it doesn't recognize, you'll probably get NameError: global name 'xx' is not defined error. In most cases, this error is triggered when Python sees a variable name (Global or Local) and doesn't know what it's for. These errors can happen if you forget to initialize a variable , if you misspell a variable, or if you misspell a reserved word such as "True". Before you use the global variable in your function for reading, it must be first initialized somewhere: either outside of the function or inside it.

http://net-informations.com/python/iq/global.htm