1 from django.db import transaction

     2 

     3 class TransactionMiddleware(object):

     4     """

     5     Transaction middleware. If this is enabled, each view function will be run

     6     with commit_on_response activated - that way a save() doesn't do a direct

     7     commit, the commit is done when a successful response is created. If an

     8     exception happens, the database is rolled back.

     9     """

    10     def process_request(self, request):

    11         """Enters transaction management"""

    12         transaction.enter_transaction_management()

    13         transaction.managed(True)

    14 

    15     def process_exception(self, request, exception):

    16         """Rolls back the database and leaves transaction management"""

    17         if transaction.is_dirty():

    18             transaction.rollback()

    19         transaction.leave_transaction_management()

    20 

    21     def process_response(self, request, response):

    22         """Commits and leaves transaction management."""

    23         if transaction.is_managed():

    24             if transaction.is_dirty():

    25                 transaction.commit()

    26             transaction.leave_transaction_management()

    27         return response