• Language: en
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  • Documentation version: 1.7

Source code for django.middleware.transaction

import warnings

from django.core.exceptions import MiddlewareNotUsed
from django.db import connection, transaction
from django.utils.deprecation import RemovedInDjango18Warning

[docs]class TransactionMiddleware(object): """ Transaction middleware. If this is enabled, each view function will be run with commit_on_response activated - that way a save() doesn't do a direct commit, the commit is done when a successful response is created. If an exception happens, the database is rolled back. """ def __init__(self): warnings.warn( "TransactionMiddleware is deprecated in favor of ATOMIC_REQUESTS.", RemovedInDjango18Warning, stacklevel=2) if connection.settings_dict['ATOMIC_REQUESTS']: raise MiddlewareNotUsed def process_request(self, request): """Enters transaction management""" transaction.enter_transaction_management() def process_exception(self, request, exception): """Rolls back the database and leaves transaction management""" if transaction.is_dirty(): # This rollback might fail because of network failure for example. # If rollback isn't possible it is impossible to clean the # connection's state. So leave the connection in dirty state and # let request_finished signal deal with cleaning the connection. transaction.rollback() transaction.leave_transaction_management() def process_response(self, request, response): """Commits and leaves transaction management.""" if not transaction.get_autocommit(): if transaction.is_dirty(): # Note: it is possible that the commit fails. If the reason is # closed connection or some similar reason, then there is # little hope to proceed nicely. However, in some cases ( # deferred foreign key checks for exampl) it is still possible # to rollback(). try: transaction.commit() except Exception: # If the rollback fails, the transaction state will be # messed up. It doesn't matter, the connection will be set # to clean state after the request finishes. And, we can't # clean the state here properly even if we wanted to, the # connection is in transaction but we can't rollback... transaction.rollback() transaction.leave_transaction_management() raise transaction.leave_transaction_management() return response
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