from django.contrib.contenttypes.models import ContentType
from django.core.exceptions import ValidationError
from django.db import models
-from django.template import Template, loader, loader_tags
+from django.template import loader, loader_tags, Parser, Lexer, Template
import re
+from philo.models.fields import TemplateField
from philo.contrib.penfield.templatetags.embed import EmbedNode
+from philo.utils import nodelist_crawl
embed_re = re.compile("{% embed (?P<app_label>\w+)\.(?P<model>\w+) (?P<pk>)\w+ %}")
-class TemplateField(models.TextField):
- def validate(self, value, model_instance):
- """For value (a template), make sure that all included templates exist."""
- super(TemplateField, self).validate(value, model_instance)
- try:
- self.validate_template(self.to_template(value))
- except Exception, e:
- raise ValidationError("Template code invalid. Error was: %s: %s" % (e.__class__.__name__, e))
-
- def validate_template(self, template):
- for node in template.nodelist:
- if isinstance(node, loader_tags.ExtendsNode):
- extended_template = node.get_parent(Context())
- self.validate_template(extended_template)
- elif isinstance(node, loader_tags.IncludeNode):
- included_template = loader.get_template(node.template_name.resolve(Context()))
- self.validate_template(extended_template)
-
- def to_template(self, value):
- return Template(value)
-
-
-class EmbedField(TemplateField):
- def validate_template(self, template):
- """Check to be sure that the embedded instances and templates all exist."""
- for node in template.nodelist:
- if isinstance(node, loader_tags.ExtendsNode):
- extended_template = node.get_parent(Context())
- self.validate_template(extended_template)
- elif isinstance(node, loader_tags.IncludeNode):
- included_template = loader.get_template(node.template_name.resolve(Context()))
- self.validate_template(extended_template)
- elif isinstance(node, EmbedNode):
- if node.template_name is not None:
- embedded_template = loader.get_template(node.template_name)
- self.validate_template(embedded_template)
- elif node.object_pk is not None:
- embedded_instance = node.model.objects.get(pk=node.object_pk)
-
- def to_template(self, value):
- return Template("{% load embed %}" + value)
-
-
class Embed(models.Model):
- embedder_embed_field = models.CharField(max_length=255)
-
- embedder_contenttype = models.ForeignKey(ContentType, related_name="embedder_related")
+ embedder_content_type = models.ForeignKey(ContentType, related_name="embedder_related")
embedder_object_id = models.PositiveIntegerField()
- embedder = generic.GenericForeignKey("embedder_contenttype", "embedder_object_id")
+ embedder = generic.GenericForeignKey("embedder_content_type", "embedder_object_id")
- embedded_contenttype = models.ForeignKey(ContentType, related_name="embedded_related")
+ embedded_content_type = models.ForeignKey(ContentType, related_name="embedded_related")
embedded_object_id = models.PositiveIntegerField()
- embedded = generic.GenericForeignKey("embedded_contenttype", "embedded_object_id")
+ embedded = generic.GenericForeignKey("embedded_content_type", "embedded_object_id")
def delete(self):
- # Unclear whether this would be called by a cascading deletion.
-
+ # This needs to be called manually.
super(Embed, self).delete()
+
+ # Cycle through all the fields in the embedder and remove all references
+ # to the embedded object.
+ embedder = self.embedder
+ for field in embedder._meta.fields:
+ if isinstance(field, EmbedField):
+ attr = getattr(embedder, field.attname)
+ setattr(embedder, field.attname, attr.replace(self.get_embed_tag(), ''))
+
+ embedder.save()
+
+ def get_embed_tag(self):
+ """Convenience function to construct the embed tag that would create this instance."""
+ ct = self.embedded_content_type
+ return "{%% embed %s.%s %s %%}" % (ct.app_label, ct.model, self.embedded_object_id)
class Meta:
app_label = 'penfield'
-class Test(models.Model):
- template = TemplateField()
- embedder = EmbedField()
+def sync_embedded_instances(model_instance, embedded_instances):
+ model_instance_ct = ContentType.objects.get_for_model(model_instance)
- class Meta:
- app_label = 'penfield'
\ No newline at end of file
+ # Cycle through all the embedded instances and make sure that they are linked to
+ # the model instance. Track their pks.
+ new_embed_pks = []
+ for embedded_instance in embedded_instances:
+ embedded_instance_ct = ContentType.objects.get_for_model(embedded_instance)
+ new_embed = Embed.objects.get_or_create(embedder_content_type=model_instance_ct, embedder_object_id=model_instance.id, embedded_content_type=embedded_instance_ct, embedded_object_id=embedded_instance.id)[0]
+ new_embed_pks.append(new_embed.pk)
+
+ # Then, delete all embed objects related to this model instance which do not relate
+ # to one of the newly embedded instances.
+ Embed.objects.filter(embedder_content_type=model_instance_ct, embedder_object_id=model_instance.id).exclude(pk__in=new_embed_pks).delete()
+
+
+class EmbedField(TemplateField):
+ def process_node(self, node, results):
+ if isinstance(node, EmbedNode) and node.instance is not None:
+ if not node.instance:
+ raise ValidationError("Instance with content type %s.%s and id %s does not exist." % (node.content_type.app_label, node.content_type.model, node.object_pk))
+
+ results.append(node.instance)
+
+ def clean(self, value, model_instance):
+ value = super(EmbedField, self).clean(value, model_instance)
+
+ if not hasattr(model_instance, '_embedded_instances'):
+ model_instance._embedded_instances = set()
+
+ model_instance._embedded_instances |= set(nodelist_crawl(Template(value).nodelist, self.process_node))
+
+ return value
+
+
+try:
+ from south.modelsinspector import add_introspection_rules
+except ImportError:
+ pass
+else:
+ add_introspection_rules([], ["^philo\.contrib\.penfield\.embed\.EmbedField"])
+
+
+# Add a post-save signal function to run the syncer.
+def post_save_embed_sync(sender, instance, **kwargs):
+ if hasattr(instance, '_embedded_instances') and instance._embedded_instances:
+ sync_embedded_instances(instance, instance._embedded_instances)
+models.signals.post_save.connect(post_save_embed_sync)
+
+
+# Deletions can't cascade automatically without a GenericRelation - but there's no good way of
+# knowing what models should have one. Anything can be embedded! Also, cascading would probably
+# bypass the Embed model's delete method.
+def post_delete_cascade(sender, instance, **kwargs):
+ ct = ContentType.objects.get_for_model(sender)
+ embeds = Embed.objects.filter(embedded_content_type=ct, embedded_object_id=instance.id)
+ for embed in embeds:
+ embed.delete()
+ Embed.objects.filter(embedder_content_type=ct, embedder_object_id=instance.id).delete()
+models.signals.post_delete.connect(post_delete_cascade)
\ No newline at end of file
git.ithinksw.org / philo.git / blobdiff