'''
Recieving methods for signals go here.
'''
import logging
from django.db.models.signals import pre_save, post_save, m2m_changed
from django.db import IntegrityError
from django.utils.translation import gettext_lazy as _
from django.template.defaultfilters import truncatewords, truncatechars
from django.dispatch import receiver
from .models import Outline, StoryElementNode, ArcElementNode, CharacterInstance, LocationInstance
from .models import STORY_NODE_ELEMENT_DEFINITIONS, ArcIntegrityError
from .signals import tree_manipulation
logger = logging.getLogger(name='Signals')
# Model-based signal logic appears below here.
[docs]@receiver(pre_save, sender=ArcElementNode)
def generate_headline_from_description(sender, instance, *args, **kwargs):
'''
Auto generate the headline of the node from the first lines of the description.
'''
lines = instance.description.split('\n')
headline = truncatewords(lines[0], 20)
if headline[:-1] == '…':
headline = truncatechars(headline.replace(' …', ''), 250) # Just in case the words exceed char limit.
else:
headline = truncatechars(headline, 250)
instance.headline = headline
[docs]@receiver(post_save, sender=Outline)
def story_root_for_new_outline(sender, instance, created, *args, **kwargs):
'''
If a new instance of a Outline is created, also create
the root node of the story tree.
'''
if created and isinstance(instance, Outline):
streeroot = StoryElementNode.add_root(outline=instance, story_element_type='root')
streeroot.save()
instance.refresh_from_db()
[docs]@receiver(m2m_changed, sender=ArcElementNode.assoc_characters.through)
@receiver(m2m_changed, sender=ArcElementNode.assoc_locations.through)
def arc_node_edit_add_missing_characters_and_locations_to_related_story_node(
sender,
instance,
action,
reverse,
pk_set,
*args,
**kwargs
):
'''
If an arc_element is modified and it's characters/locations are not already in the story node, add them.
We don't assume that removing the arc element would change the characters or locations as of yet.
This takes up a little more space in the database, but the additional flexibility for users is
worth it.
'''
if action == 'post_add':
logger.debug("Updating nodes after character or location change.")
if reverse:
logger.debug("Searching backwards from character or location to arc node")
# We are going to need to be querying the arc element node.
for arcnode in instance.arcelementnode_set.all().select_related('story_element_node'):
logger.debug("Scanning arc node...")
if arcnode.story_element_node:
logger.debug("Found story node to update...")
story_node = arcnode.story_element_node
if isinstance(instance, CharacterInstance):
logger.debug("Updating characters...")
story_node.assoc_characters.add(instance)
if isinstance(instance, LocationInstance):
logger.debug("updating locations...")
story_node.assoc_locations.add(instance)
else:
# We already have the arc_element_node
logger.debug('Scanning arcnode instance...')
if instance.story_element_node:
logger.debug("found story node to update...")
story_node = instance.story_element_node
if sender == ArcElementNode.assoc_characters.through:
logger.debug('Adding character')
story_node.assoc_characters.add(*pk_set)
if sender == ArcElementNode.assoc_locations.through:
logger.debug('Adding locations')
story_node.assoc_locations.add(*pk_set)
[docs]@receiver(post_save, sender=ArcElementNode)
def story_node_add_arc_element_update_characters_locations(sender, instance, created, *args, **kwargs):
'''
If an arc element is added to a story element node, add any missing elements or locations.
'''
arc_node = ArcElementNode.objects.get(pk=instance.pk)
logger.debug('Scanning arc_node %s' % arc_node)
if arc_node.arc_element_type == 'root':
logger.debug("root node. skipping...")
else:
logger.debug('Checking arc node for story element relationship...')
if arc_node.story_element_node:
logger.debug('Found a story element node for arc element...')
# This change was initiated by the arc element node as opposed to the story node.
story_node = arc_node.story_element_node
if arc_node.assoc_characters.count() > 0:
logger.debug('Found %d characters to add...' % arc_node.assoc_characters.count())
for character in arc_node.assoc_characters.all():
story_node.assoc_characters.add(character)
if arc_node.assoc_locations.count() > 0:
logger.debug('Found %d locations to add...' % arc_node.assoc_locations.count())
for location in arc_node.assoc_locations.all():
story_node.assoc_locations.add(location)
[docs]@receiver(pre_save, sender=ArcElementNode)
def validate_arc_links_same_outline(sender, instance, *args, **kwargs):
'''
Evaluates attempts to link an arc to a story node from another outline.
'''
if instance.story_element_node:
if instance.story_element_node.outline != instance.parent_outline:
raise IntegrityError(_('An arc cannot be associated with an story element from another outline.'))
[docs]@receiver(m2m_changed, sender=ArcElementNode.assoc_characters.through)
def validate_character_instance_valid_for_arc(sender, instance, action, reverse, pk_set, *args, **kwargs):
'''
Evaluate attempts to assign a character instance to ensure it is from same
outline.
'''
if action == 'pre_add':
if reverse:
# Fetch arc definition through link.
for apk in pk_set:
arc_node = ArcElementNode.objects.get(pk=apk)
if arc_node.parent_outline != instance.outline:
raise IntegrityError(_('Character Instance and Arc Element must be from same outline.'))
else:
for cpk in pk_set:
char_instance = CharacterInstance.objects.get(pk=cpk)
if char_instance.outline != instance.parent_outline:
raise IntegrityError(_('Character Instance and Arc Element must be from the same outline.'))
[docs]@receiver(m2m_changed, sender=ArcElementNode.assoc_locations.through)
def validate_location_instance_valid_for_arc(sender, instance, action, reverse, pk_set, *args, **kwargs):
'''
Evaluates attempts to add location instances to arc, ensuring they are from same outline.
'''
if action == 'pre_add':
if reverse:
# Fetch arc definition through link.
for apk in pk_set:
arc_node = ArcElementNode.objects.get(pk=apk)
if arc_node.parent_outline != instance.outline:
raise IntegrityError(_('Location instance must be from same outline as arc element.'))
else:
for lpk in pk_set:
loc_instance = LocationInstance.objects.get(pk=lpk)
if loc_instance.outline != instance.parent_outline:
raise IntegrityError(_('Location Instance must be from the same outline as arc element.'))
[docs]@receiver(m2m_changed, sender=StoryElementNode.assoc_characters.through)
def validate_character_for_story_element(sender, instance, action, reverse, pk_set, *args, **kwargs):
'''
Validates that character is from the same outline as the story node.
'''
if action == 'pre_add':
if reverse:
for spk in pk_set:
story_node = StoryElementNode.objects.get(pk=spk)
if instance.outline != story_node.outline:
raise IntegrityError(_('Character Instance must be from the same outline as story node.'))
else:
for cpk in pk_set:
char_instance = CharacterInstance.objects.get(pk=cpk)
if char_instance.outline != instance.outline:
raise IntegrityError(_('Character Instance must be from the same outline as story node.'))
[docs]@receiver(m2m_changed, sender=StoryElementNode.assoc_locations.through)
def validate_location_for_story_element(sender, instance, action, reverse, pk_set, *args, **kwargs):
'''
Validates that location is from same outline as story node.
'''
if action == 'pre_add':
if reverse:
for spk in pk_set:
story_node = StoryElementNode.objects.get(pk=spk)
if instance.outline != story_node.outline:
raise IntegrityError(_('Location must be from same outline as story node.'))
else:
for lpk in pk_set:
loc_instance = LocationInstance.objects.get(pk=lpk)
if instance.outline != loc_instance.outline:
raise IntegrityError(_('Location must be from the same outline as story node.'))
[docs]@receiver(tree_manipulation, sender=StoryElementNode)
def validate_generations_for_story_elements(
sender,
instance,
action,
target_node_type=None,
target_node=None,
pos=None,
*args,
**kwargs
):
'''
Unlike arc nodes, for which we just warn about structure, the story tree
allowed parent/child rules must be strictly enforced.
'''
if action == 'add_child':
if instance.story_element_type not in STORY_NODE_ELEMENT_DEFINITIONS[target_node_type]['allowed_parents']:
raise IntegrityError(_('%s is not an allowed child of %s' % (target_node_type,
instance.story_element_type)))
if action == 'update':
parent = instance.get_parent()
children = instance.get_children()
if parent.story_element_type not in STORY_NODE_ELEMENT_DEFINITIONS[target_node_type]['allowed_parents']:
raise IntegrityError(_('%s is not an allowed child of %s' % (target_node_type, parent.story_element_type)))
if children:
for child in children:
if target_node_type not in STORY_NODE_ELEMENT_DEFINITIONS[child.story_element_type]['allowed_parents']:
raise IntegrityError(_('%s is not permitted to be a parent of %s' % (
target_node_type, child.story_element_type)))
if action == 'add_sibling':
parent = instance.get_parent()
if parent.story_element_type not in STORY_NODE_ELEMENT_DEFINITIONS[target_node_type]['allowed_parents']:
raise IntegrityError(_('%s is not an allowed child of %s' % (target_node_type, parent.story_element_type)))
if action == 'move':
if not pos or 'sibling' in pos or 'right' in pos or 'left' in pos:
parent = target_node.get_parent()
if (parent.story_element_type not in
STORY_NODE_ELEMENT_DEFINITIONS[instance.story_element_type]['allowed_parents']):
raise IntegrityError(_('%s is not an allowed child of %s' % (
instance.story_element_type,
parent.story_element_type
)))
if 'child' in pos:
if (target_node.story_element_type not in
STORY_NODE_ELEMENT_DEFINITIONS[instance.story_element_type]['allowed_parents']):
raise IntegrityError(_('%s is not an allowed child of %s' % (
instance.story_element_type,
target_node.story_element_type
)))
[docs]@receiver(tree_manipulation, sender=ArcElementNode)
def validate_against_prohibited_actions(
sender,
instance,
action,
target_node_type=None,
target_node=None,
pos=None,
*args,
**kwargs):
if action == 'update' and 'mile' in target_node_type:
milestones = ArcElementNode.objects.filter(
arc=instance.arc,
arc_element_type=instance.arc_element_type
).exclude(pk=instance.pk).count()
if milestones:
raise ArcIntegrityError(_("You cannot have two of the same milestone within the same arc."))