from unittest import TestCase import unittest """A pseudo-REST dispatching method in which only the noun comes from the path. The action performed will depend on kwargs. """ class AmbiguousAction(Exception): def __init__(self, actions): Exception.__init__(self, "Supplied action is ambiguous.") self.actions = actions def provide_action(name, value): def provider(func): func._action_desc = (name, value) return func return provider class PrestHandler(object): def __init__(self): object.__init__(self) self.actions = {} for member in (getattr(self, m) for m in dir(self)): if not hasattr(member, '_action_desc'): continue name, value = member._action_desc if name not in self.actions: self.actions[name] = {} self.actions[name][value] = member @classmethod def add_action(klass, name, value, function): if name not in klass.actions: klass.actions[name] = {} klass.actions[name][value] = function def decode(self, path, data=None): """Convert the path into a handler, a resource, data, and extra_path""" if data is None: data = {} if len(path) < 2 or not (hasattr(self, path[1])): if len(path) == 0: resource = None else: resource = self.instantiate(**data) return self, resource, data, path[1:] if len(path) > 2: data[path[1]] = path[2] return getattr(self, path[1]).decode(path[2:], data) def default(self, *args, **kwargs): child, resource, data, extra = self.decode([None,] + list(args)) action = child.get_action(**kwargs) new_args = ([data, resource]+extra) if action is not None: return action(*new_args, **kwargs) else: return child.dispatch(*new_args, **kwargs) def get_action(self, **kwargs): """Return the action requested by kwargs, if any. Raises AmbiguousAction if more than one action matches. """ actions = [] for key in kwargs: if key in self.actions: if kwargs[key] in self.actions[key]: actions.append(self.actions[key][kwargs[key]]) if len(actions) == 0: return None elif len(actions) == 1: return actions[0] else: raise AmbiguousAction(actions) class PrestTester(TestCase): def test_decode(self): class ProjectHandler(PrestHandler): actions = {} def dispatch(self, project_data, project, *args, **kwargs): self.project_id = project_data['project'] self.project_data = project_data self.resource = project self.args = args self.kwargs = kwargs def instantiate(self, project): return [project] @provide_action('action', 'Save') def save(self, project_data, project, *args, **kwargs): self.action = "save" @provide_action('behavior', 'Update') def update(self, project_data, project, *args, **kwargs): self.action = "update" foo = PrestHandler() foo.project = ProjectHandler() handler, resource, data, extra = foo.decode([None, 'project', '83', 'bloop', 'yeah']) assert handler is foo.project self.assertEqual({'project': '83'}, data) self.assertEqual(['bloop', 'yeah'], extra) foo.default(*['project', '27', 'extra'], **{'a':'b', 'b':'97'}) self.assertEqual(foo.project.args, ('extra',)) self.assertEqual(foo.project.kwargs, {'a':'b', 'b':'97'}) self.assertEqual(foo.project.project_data, {'project': '27'}) self.assertEqual(foo.project.resource, ['27']) foo.default(*['project', '27', 'extra'], **{'action':'Save', 'b':'97'}) self.assertEqual(foo.project.action, 'save') foo.default(*['project', '27', 'extra'], **{'behavior':'Update', 'b':'97'}) self.assertEqual(foo.project.action, 'update') self.assertRaises(AmbiguousAction, foo.default, *['project', '27', 'extra'], **{'behavior':'Update', 'action':'Save', 'b':'97'}) class BugHandler(PrestHandler): actions = {} def dispatch(self, bug_data, bug, *args, **kwargs): self.project_id = project_data['project'] self.project_data = project_data self.resource = project self.args = args self.kwargs = kwargs def instantiate(self, project, bug): return [project, bug] @provide_action('action', 'Save') def save(self, project_data, project, *args, **kwargs): self.action = "save" @provide_action('behavior', 'Update') def update(self, project_data, project, *args, **kwargs): self.action = "update" foo.project.bug = BugHandler() handler, resource, data, extra = foo.decode([None, 'project', '83', 'bug', '92']) assert handler is foo.project.bug self.assertEqual(resource[0], '83') self.assertEqual(resource[1], '92') self.assertEqual([], extra) self.assertEqual(data['project'], '83') self.assertEqual(data['bug'], '92') def test(): patchesTestSuite = unittest.makeSuite(PrestTester,'test') runner = unittest.TextTestRunner(verbosity=0) return runner.run(patchesTestSuite) if __name__ == "__main__": test()