def __init__(self, app_namespace, flow_namespace, position, state,
state_store, url_args, url_kwargs):
self._app_namespace = app_namespace
self._flow_namespace = flow_namespace
self._position = position
self._state = state
self._flow_components = []
self.state_store = state_store
self._url_args = url_args or []
self._url_kwargs = url_kwargs or {}
for flow_component_class in self._position.flow_component_classes:
flow_component = flow_component_class()
flow_component._flow_position_instance = self
flow_component.set_url_args(*self._url_args, **self._url_kwargs)
flow_component.state = state
flow_component.task_id = self.task_id
flow_component.app_namespace = self._app_namespace
flow_component.flow_namespace = self._flow_namespace
self._flow_components.append(flow_component)
self._history = FlowHistory(self)
self._validate()
def __init__(self, app_namespace, flow_namespace, position, state, state_store, url_args, url_kwargs):
self._app_namespace = app_namespace
self._flow_namespace = flow_namespace
self._position = position
self._state = state
self._flow_components = []
self.state_store = state_store
self._url_args = url_args or []
self._url_kwargs = url_kwargs or {}
for flow_component_class in self._position.flow_component_classes:
flow_component = flow_component_class()
flow_component._flow_position_instance = self
flow_component.set_url_args(*self._url_args, **self._url_kwargs)
flow_component.state = state
flow_component.task_id = self.task_id
flow_component.app_namespace = self._app_namespace
flow_component.flow_namespace = self._flow_namespace
self._flow_components.append( flow_component )
self._history = FlowHistory(self)
self._validate()
class FlowPositionInstance(object):
"""
A FlowPositionInstance represents a concrete instance of a PossibleFlowPosition -
that is, a user is currently performing an action as part of a flow
"""
def __init__(self, app_namespace, flow_namespace, position, state,
state_store, url_args, url_kwargs):
self._app_namespace = app_namespace
self._flow_namespace = flow_namespace
self._position = position
self._state = state
self._flow_components = []
self.state_store = state_store
self._url_args = url_args or []
self._url_kwargs = url_kwargs or {}
for flow_component_class in self._position.flow_component_classes:
flow_component = flow_component_class()
flow_component._flow_position_instance = self
flow_component.set_url_args(*self._url_args, **self._url_kwargs)
flow_component.state = state
flow_component.task_id = self.task_id
flow_component.app_namespace = self._app_namespace
flow_component.flow_namespace = self._flow_namespace
self._flow_components.append(flow_component)
self._history = FlowHistory(self)
self._validate()
def _validate(self):
pass
# TODO: assert that only the last element is an Action and that the
# rest are Scaffolds
@property
def task_id(self):
return self._state['_id']
def get_root_component(self):
return self._flow_components[0]
def get_action(self):
return self._flow_components[-1]
def get_back_url(self):
return self._history.get_back_url()
def get_absolute_url(self, include_flow_id=True):
args = []
kwargs = {}
for flow_component in self._flow_components:
flow_args, flow_kwargs = flow_component.get_url_args()
args += flow_args
kwargs.update(flow_kwargs)
url_name = self._position.url_name
url = reverse(url_name, args=args, kwargs=kwargs)
if include_flow_id:
separator = '&' if '?' in url else '?'
return '%(root)s%(url)s%(separator)s%(task_id_param_name)s=%(task_id)s' % {
'root': config.FLOWS_SITE_ROOT,
'url': url,
'separator': separator,
'task_id_param_name': config.FLOWS_TASK_ID_PARAM,
'task_id': self.task_id
}
else:
return '%(root)s%(url)s' % {
'root': config.FLOWS_SITE_ROOT,
'url': url
}
def position_instance_for(self, component_class_or_name):
# figure out where we're being sent to
FC = get_by_class_or_name(component_class_or_name)
# it should be a sibling of one of the current items
# for example, if we are in position [A,B,E]:
#
# A
# / | \
# B C D
# / \ | \
# E F G H
#
# E can send to F (its own sibling) or C (sibling of its parent)
for fci in self._flow_components[
-2::-1]: # go backwards but skip the last element (the action)
if FC in fci.action_set:
# we found the relevant action set, which means we know the root
# part of the tree, and now we can construct the rest
idx = self._flow_components.index(fci)
break
else:
raise ValueError('Could not figure out how to redirect to %s' % FC)
# so the new tree is from the root to the parent of the one we just found,
# coupled with the initial subtree from the component we're tring to redirect
# to
tree_root = self._position.flow_component_classes[:idx + 1]
# figure out the action tree for the new first component - either
# we have been given an action, in which case it's just one single
# item, or we have been given a scaffold, in which case there could
# be a list of [scaffold, scaffold..., action]
new_subtree = FC.get_initial_action_tree()
# we use our current tree and replace the current leaf with this new
# subtree to get the new position
new_position = PossibleFlowPosition(self._app_namespace,
self._flow_namespace,
tree_root + new_subtree)
# now create an instance of the position with the current state
return new_position.create_instance(self._state, self.state_store,
self._url_args, self._url_kwargs)
def handle(self, request, *args, **kwargs):
# first validate that we can actually run by checking for
# required state, for example
response = None
for flow_component in self._flow_components:
response = flow_component.check_preconditions(request)
if response is not None:
break
if response is None:
# now call each of the prepare methods for the components
for flow_component in self._flow_components:
# TODO: passing in *args and **kwargs to prepare is deprecated
response = flow_component.prepare(request, *args, **kwargs)
if response is not None:
# we allow prepare methods to give out responses if they
# want to, eg, redirect
break
if response is None:
# FIXME: mjtamlyn promises to fix this in Django 1.7, but right now we need
# to set up the magic attributes usually set up by a closure in View.as_view
# so we can call dispatch on Django>1.5
action = self.get_action()
if hasattr(action, 'request'):
raise Exception('Action re-use?')
action.request = request
action.args = args
action.kwargs = kwargs
# now that everything is set up, we can handle the request
response = self.get_action().dispatch(request, *args, **kwargs)
# if this is a GET request, then we displayed something to the user, so
# we should record this in the history, unless the request returned a
# redirect, in which case we haven't displayed anything
if request.method == 'GET' and not isinstance(
response, HttpResponseRedirect):
self._history.add_to_history(self)
# now we have a response, we need to decide what to do with it
for flow_component in self._flow_components[::
-1]: # go from leaf to root, ie, backwards
response = flow_component.handle_response(response)
# now we have some kind of response, figure out what it is exactly
if response == COMPLETE:
# this means that the entire flow finished - we should redirect
# to the on_complete url if we have one, or get upset if we don't
next_url = self._state.get('_on_complete', None)
if next_url is None:
# oh, we don't know where to go...
raise ImproperlyConfigured(
'Flow completed without an _on_complete URL or an explicit redirect - %s'
% self.__repr__())
else:
response = redirect(next_url)
# if we are done, then we should remove the task state
self.state_store.delete_state(self.task_id)
else:
# update the state if necessary
self.state_store.put_state(self.task_id, self._state)
if inspect.isclass(response):
# we got given a class, which implies the code should redirect
# to this new (presumably Action) class
response = redirect(
self.position_instance_for(response).get_absolute_url())
elif isinstance(response, Action):
# this is a new action for the user, so redirect to it
absurl = response.get_absolute_url()
response = redirect(absurl)
elif isinstance(response, basestring):
# this is a string which should be the name of an action
# which couldn't be referenced as a class for some reason
flow_component = get_by_class_or_name(response)
response = redirect(flow_component.get_absolute_url())
return response
def __repr__(self):
return 'Instance of %s' % self._position.__repr__()
class FlowPositionInstance(object):
"""
A FlowPositionInstance represents a concrete instance of a PossibleFlowPosition -
that is, a user is currently performing an action as part of a flow
"""
def __init__(self, app_namespace, flow_namespace, position, state, state_store, url_args, url_kwargs):
self._app_namespace = app_namespace
self._flow_namespace = flow_namespace
self._position = position
self._state = state
self._flow_components = []
self.state_store = state_store
self._url_args = url_args or []
self._url_kwargs = url_kwargs or {}
for flow_component_class in self._position.flow_component_classes:
flow_component = flow_component_class()
flow_component._flow_position_instance = self
flow_component.set_url_args(*self._url_args, **self._url_kwargs)
flow_component.state = state
flow_component.task_id = self.task_id
flow_component.app_namespace = self._app_namespace
flow_component.flow_namespace = self._flow_namespace
self._flow_components.append( flow_component )
self._history = FlowHistory(self)
self._validate()
def _validate(self):
pass
# TODO: assert that only the last element is an Action and that the
# rest are Scaffolds
@property
def task_id(self):
return self._state['_id']
def get_root_component(self):
return self._flow_components[0]
def get_action(self):
return self._flow_components[-1]
def get_back_url(self):
return self._history.get_back_url()
def get_absolute_url(self, include_flow_id=True):
args = []
kwargs = {}
for flow_component in self._flow_components:
flow_args, flow_kwargs = flow_component.get_url_args()
args += flow_args
kwargs.update(flow_kwargs)
url_name = self._position.url_name
url = reverse(url_name, args=args, kwargs=kwargs)
if include_flow_id:
separator = '&' if '?' in url else '?'
return '%(root)s%(url)s%(separator)s%(task_id_param_name)s=%(task_id)s' % {
'root': config.FLOWS_SITE_ROOT,
'url': url, 'separator': separator,
'task_id_param_name': config.FLOWS_TASK_ID_PARAM,
'task_id': self.task_id }
else:
return '%(root)s%(url)s' % { 'root': config.FLOWS_SITE_ROOT, 'url': url }
def position_instance_for(self, component_class_or_name):
# figure out where we're being sent to
FC = get_by_class_or_name(component_class_or_name)
# it should be a sibling of one of the current items
# for example, if we are in position [A,B,E]:
#
# A
# / | \
# B C D
# / \ | \
# E F G H
#
# E can send to F (its own sibling) or C (sibling of its parent)
for fci in self._flow_components[-2::-1]: # go backwards but skip the last element (the action)
if FC in fci.action_set:
# we found the relevant action set, which means we know the root
# part of the tree, and now we can construct the rest
idx = self._flow_components.index(fci)
break
else:
raise ValueError('Could not figure out how to redirect to %s' % FC)
# so the new tree is from the root to the parent of the one we just found,
# coupled with the initial subtree from the component we're tring to redirect
# to
tree_root = self._position.flow_component_classes[:idx+1]
# figure out the action tree for the new first component - either
# we have been given an action, in which case it's just one single
# item, or we have been given a scaffold, in which case there could
# be a list of [scaffold, scaffold..., action]
new_subtree = FC.get_initial_action_tree()
# we use our current tree and replace the current leaf with this new
# subtree to get the new position
new_position = PossibleFlowPosition(self._app_namespace, self._flow_namespace, tree_root + new_subtree)
# now create an instance of the position with the current state
return new_position.create_instance(self._state, self.state_store, self._url_args, self._url_kwargs)
def handle(self, request, *args, **kwargs):
# first validate that we can actually run by checking for
# required state, for example
response = None
for flow_component in self._flow_components:
response = flow_component.check_preconditions(request)
if response is not None:
break
if response is None:
# now call each of the prepare methods for the components
for flow_component in self._flow_components:
# TODO: passing in *args and **kwargs to prepare is deprecated
response = flow_component.prepare(request, *args, **kwargs)
if response is not None:
# we allow prepare methods to give out responses if they
# want to, eg, redirect
break
if response is None:
# FIXME: mjtamlyn promises to fix this in Django 1.7, but right now we need
# to set up the magic attributes usually set up by a closure in View.as_view
# so we can call dispatch on Django>1.5
action = self.get_action()
if hasattr(action, 'request'):
raise Exception('Action re-use?')
action.request = request
action.args = args
action.kwargs = kwargs
# now that everything is set up, we can handle the request
response = self.get_action().dispatch(request, *args, **kwargs)
# if this is a GET request, then we displayed something to the user, so
# we should record this in the history, unless the request returned a
# redirect, in which case we haven't displayed anything
if request.method == 'GET' and not isinstance(response, HttpResponseRedirect):
self._history.add_to_history(self)
# now we have a response, we need to decide what to do with it
for flow_component in self._flow_components[::-1]: # go from leaf to root, ie, backwards
response = flow_component.handle_response(response)
# now we have some kind of response, figure out what it is exactly
if response == COMPLETE:
# this means that the entire flow finished - we should redirect
# to the on_complete url if we have one, or get upset if we don't
next_url = self._state.get('_on_complete', None)
if next_url is None:
# oh, we don't know where to go...
raise ImproperlyConfigured('Flow completed without an _on_complete URL or an explicit redirect - %s' % self.__repr__())
else:
response = redirect(next_url)
# if we are done, then we should remove the task state
self.state_store.delete_state(self.task_id)
else:
# update the state if necessary
self.state_store.put_state(self.task_id, self._state)
if inspect.isclass(response):
# we got given a class, which implies the code should redirect
# to this new (presumably Action) class
response = redirect(self.position_instance_for(response).get_absolute_url())
elif isinstance(response, Action):
# this is a new action for the user, so redirect to it
absurl = response.get_absolute_url()
response = redirect(absurl)
elif isinstance(response, basestring):
# this is a string which should be the name of an action
# which couldn't be referenced as a class for some reason
flow_component = get_by_class_or_name(response)
response = redirect(flow_component.get_absolute_url())
return response
def __repr__(self):
return 'Instance of %s' % self._position.__repr__()
