class Condition(ConditionMixin):
def __init__(self, left_operand, right_operand, operator):
self._validate(left_operand, right_operand, operator)
self._left_operand = Operand(left_operand)
self._right_operand = Operand(right_operand)
self._operator = operator
def to_str(self):
left_operand_str = self._left_operand.to_str()
right_operand_str = self._right_operand.to_str()
return CONDITION_TMPL % (left_operand_str, self._operator.string_repr,
right_operand_str)
def get_data(self, data=None):
if data is None:
data = []
self._add_operand_data(self._left_operand, data)
self._add_operand_data(self._right_operand, data)
return data
@staticmethod
def _add_operand_data(operand, data):
if operand.is_data():
data.append(operand.instance)
elif operand.is_condition():
operand.instance.get_data(data)
def get_models(self):
return self._get_models(Operand(self))
def _get_models(self, operand):
if operand.is_condition():
return self._get_models(operand.instance.left_operand) | \
self._get_models(operand.instance.right_operand)
return {operand.instance.model} if operand.is_field() else set()
@staticmethod
def _validate(left_operand, right_operand, operator):
if operator in [operators.AND, operators.OR] \
and not (isinstance(left_operand, Condition)
and isinstance(right_operand, Condition)):
raise ConditionError(
'The condition can not be constructed. '
'Are you sure that the condition is in parentheses?')
@property
def left_operand(self):
return self._left_operand
@property
def right_operand(self):
return self._right_operand
def test_to_str(self, field_to_str, condition_to_str):
condition_to_str.return_value = 'test_condition'
field_to_str.return_value = 'test_field'
operand = Operand(Condition(TestModel.test_field_one,
TestModel.test_field_two, Operator('=')))
self.assertEqual(operand.to_str(), 'test_condition')
self.assertTrue(condition_to_str.called)
operand = Operand(TestModel.test_field_one)
self.assertEqual(operand.to_str(), 'test_field')
self.assertTrue(field_to_str.called)
operand = Operand(1)
self.assertEqual(operand.to_str(), '%s')
operand = Operand(None)
self.assertEqual(operand.to_str(), '%s')
operand = Operand(EmptyOperand())
self.assertEqual(operand.to_str(), '')