def get_attr_value(obj, attr_path):
"""This function gets an attribute value from an object. If the attribute
is a method with no arguments (or arguments with default values) it calls
the method. If the expression string has a path to a child attribute, it
supports.
Examples:
attribute_name = 'name'
attribute_name = 'name.upper'
attribute_name = 'customer.name.lower'
"""
if not attr_path:
raise Exception('Invalid attribute path \'%s\'' % attr_path)
parts = attr_path.split('.')
try:
val = getattr(obj, parts[0])
except AttributeError:
try:
val = obj[parts[0]]
except (KeyError, TypeError):
raise AttributeNotFound(
'There is no attribute nor key "%s" in the object "%s"' %
(parts[0], repr(obj)))
if len(parts) > 1:
val = get_attr_value(val, '.'.join(parts[1:]))
if callable(val):
val = val()
return val
def get_object_value(self, obj=None, attribute_name=None, action=None):
"""Override this method to customize the behaviour of object getting its value."""
try:
return self.parent.get_object_value(obj, attribute_name, action)
except AttributeError:
raise AttributeNotFound()