"""
Setup pubsub for the *arg1* message protocol. In a default pubsub installation
the default protocol is *kargs*.

This module must be imported before the first ``from pubsub import pub``
statement in the application. Once :mod:pub has been imported, the messaging 
protocol cannot be changed (i.e., importing it after the first 
``from pubsub import pub`` statement has undefined behavior). 
::

    from .. import setuparg1
    from .. import pub

The *arg1* protocol is identical to the legacy messaging protocol from 
first version of pubsub (when it was still part of wxPython) and 
is *deprecated*. This module is therefore *deprecated*. 
"""

"""
:copyright: Copyright since 2006 by Oliver Schoenborn, all rights reserved.
:license: BSD, see LICENSE_BSD_Simple.txt for details.
"""

from . import policies
policies.msgDataProtocol = 'arg1'


def enforceArgName(commonName):
    """This will configure pubsub to require that all listeners use 
    the same argument name (*commonName*) as first parameter. This  
    is a ueful first step in migrating an application that has been 
    using *arg1* protocol to the more powerful *kwargs* protocol. """
    policies.setMsgDataArgName(1, commonName)