app/django/middleware/transaction.py
author Daniel Hans <Daniel.M.Hans@gmail.com>
Tue, 03 Nov 2009 00:50:23 +0100
changeset 3075 1e78db95e38a
parent 54 03e267d67478
permissions -rw-r--r--
getListContentForData function added to lists helper. It allows to manually set a list of entities which is to be displayed on the view. Previously, the only function was getListContent, but it retrived data on its own by a single query. The new function can be useful whenever it is impossible or very awkward to obtain entities in such a way (for example more sophisticated SQL statements). Additionally, the getListContent function is reconstructed so that it collects the data first and then calls getListContentForData.

from django.db import transaction

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 process_request(self, request):
        """Enters transaction management"""
        transaction.enter_transaction_management()
        transaction.managed(True)

    def process_exception(self, request, exception):
        """Rolls back the database and leaves transaction management"""
        if transaction.is_dirty():
            transaction.rollback()
        transaction.leave_transaction_management()

    def process_response(self, request, response):
        """Commits and leaves transaction management."""
        if transaction.is_managed():
            if transaction.is_dirty():
                transaction.commit()
            transaction.leave_transaction_management()
        return response