"""Module implementing error-catching version of send (sendRobust)"""

from django.dispatch.dispatcher import Any, Anonymous, liveReceivers, getAllReceivers

from django.dispatch.robustapply import robustApply

def sendRobust(

    signal=Any, 

    sender=Anonymous, 

    *arguments, **named

):

    """Send signal from sender to all connected receivers catching errors

    signal -- (hashable) signal value, see connect for details

    sender -- the sender of the signal

        if Any, only receivers registered for Any will receive

        the message.

        if Anonymous, only receivers registered to receive

        messages from Anonymous or Any will receive the message

        Otherwise can be any python object (normally one

        registered with a connect if you actually want

        something to occur).

    arguments -- positional arguments which will be passed to

        *all* receivers. Note that this may raise TypeErrors

        if the receivers do not allow the particular arguments.

        Note also that arguments are applied before named

        arguments, so they should be used with care.

    named -- named arguments which will be filtered according

        to the parameters of the receivers to only provide those

        acceptable to the receiver.

    Return a list of tuple pairs [(receiver, response), ... ]

    if any receiver raises an error (specifically any subclass of Exception),

    the error instance is returned as the result for that receiver.

    """

    # Call each receiver with whatever arguments it can accept.

    # Return a list of tuple pairs [(receiver, response), ... ].

    responses = []

    for receiver in liveReceivers(getAllReceivers(sender, signal)):

        try:

            response = robustApply(

                receiver,

                signal=signal,

                sender=sender,

                *arguments,

                **named

            )

        except Exception, err:

            responses.append((receiver, err))

        else:

            responses.append((receiver, response))

    return responses