def _transaction_ctx_for_context(context):
by_thread = _transaction_contexts_by_thread(context)
try:
return by_thread.current
except AttributeError:
raise exception.NoEngineContextEstablished(
"No TransactionContext is established for "
"this %s object within the current thread. " % context)
def _property_for_context(context):
try:
transaction_context = context.transaction_ctx
except exception.NoEngineContextEstablished:
raise exception.NoEngineContextEstablished(
"No TransactionContext is established for "
"this %s object within the current thread; "
"the %r attribute is unavailable." % (context, attr))
else:
result = getter(transaction_context)
if result is None:
raise exception.ContextNotRequestedError(
"The '%s' context attribute was requested but "
"it has not been established for this context." % attr)
return result
