contrib/penfield/embed.py

   1 from django.contrib.contenttypes import generic
   2 from django.contrib.contenttypes.models import ContentType
   3 from django.core.exceptions import ValidationError
   4 from django.db import models
   5 from django.template import Template, loader, loader_tags
   6 import re
   7 from philo.contrib.penfield.templatetags.embed import EmbedNode
   8
   9
  10 embed_re = re.compile("{% embed (?P<app_label>\w+)\.(?P<model>\w+) (?P<pk>)\w+ %}")
  11
  12
  13 class TemplateField(models.TextField):
  14         def validate(self, value, model_instance):
  15                 """For value (a template), make sure that all included templates exist."""
  16                 super(TemplateField, self).validate(value, model_instance)
  17                 try:
  18                         self.validate_template(self.to_template(value))
  19                 except Exception, e:
  20                         raise ValidationError("Template code invalid. Error was: %s: %s" % (e.__class__.__name__, e))
  21
  22         def validate_template(self, template):
  23                 for node in template.nodelist:
  24                         if isinstance(node, loader_tags.ExtendsNode):
  25                                 extended_template = node.get_parent(Context())
  26                                 self.validate_template(extended_template)
  27                         elif isinstance(node, loader_tags.IncludeNode):
  28                                 included_template = loader.get_template(node.template_name.resolve(Context()))
  29                                 self.validate_template(extended_template)
  30
  31         def to_template(self, value):
  32                 return Template(value)
  33
  34
  35 class EmbedField(TemplateField):
  36         def validate_template(self, template):
  37                 """Check to be sure that the embedded instances and templates all exist."""
  38                 for node in template.nodelist:
  39                         if isinstance(node, loader_tags.ExtendsNode):
  40                                 extended_template = node.get_parent(Context())
  41                                 self.validate_template(extended_template)
  42                         elif isinstance(node, loader_tags.IncludeNode):
  43                                 included_template = loader.get_template(node.template_name.resolve(Context()))
  44                                 self.validate_template(extended_template)
  45                         elif isinstance(node, EmbedNode):
  46                                 if node.template_name is not None:
  47                                         embedded_template = loader.get_template(node.template_name)
  48                                         self.validate_template(embedded_template)
  49                                 elif node.object_pk is not None:
  50                                         embedded_instance = node.model.objects.get(pk=node.object_pk)
  51
  52         def to_template(self, value):
  53                 return Template("{% load embed %}" + value)
  54
  55
  56 class Embed(models.Model):
  57         embedder_embed_field = models.CharField(max_length=255)
  58
  59         embedder_contenttype = models.ForeignKey(ContentType, related_name="embedder_related")
  60         embedder_object_id = models.PositiveIntegerField()
  61         embedder = generic.GenericForeignKey("embedder_contenttype", "embedder_object_id")
  62
  63         embedded_contenttype = models.ForeignKey(ContentType, related_name="embedded_related")
  64         embedded_object_id = models.PositiveIntegerField()
  65         embedded = generic.GenericForeignKey("embedded_contenttype", "embedded_object_id")
  66
  67         def delete(self):
  68                 # Unclear whether this would be called by a cascading deletion.
  69
  70                 super(Embed, self).delete()
  71
  72         class Meta:
  73                 app_label = 'penfield'
  74
  75
  76 class Test(models.Model):
  77         template = TemplateField()
  78         embedder = EmbedField()
  79
  80         class Meta:
  81                 app_label = 'penfield'