models/nodes.py

   1 from django.db import models
   2 from django.contrib.contenttypes.models import ContentType
   3 from django.contrib.contenttypes import generic
   4 from django.contrib.sites.models import Site
   5 from django.http import HttpResponse, HttpResponseServerError, HttpResponseRedirect
   6 from django.core.servers.basehttp import FileWrapper
   7 from django.core.urlresolvers import resolve, clear_url_caches
   8 from django.template import add_to_builtins as register_templatetags
   9 from inspect import getargspec
  10 from philo.models.base import TreeEntity, Entity, QuerySetMapper, register_value_model
  11 from philo.utils import ContentTypeSubclassLimiter
  12 from philo.validators import RedirectValidator
  13 from philo.exceptions import ViewDoesNotProvideSubpaths, AncestorDoesNotExist
  14 from philo.signals import view_about_to_render, view_finished_rendering
  15
  16
  17 _view_content_type_limiter = ContentTypeSubclassLimiter(None)
  18
  19
  20 class Node(TreeEntity):
  21         view_content_type = models.ForeignKey(ContentType, related_name='node_view_set', limit_choices_to=_view_content_type_limiter)
  22         view_object_id = models.PositiveIntegerField()
  23         view = generic.GenericForeignKey('view_content_type', 'view_object_id')
  24
  25         @property
  26         def accepts_subpath(self):
  27                 if self.view:
  28                         return self.view.accepts_subpath
  29                 return False
  30
  31         def render_to_response(self, request, path=None, subpath=None, extra_context=None):
  32                 return self.view.render_to_response(self, request, path, subpath, extra_context)
  33
  34         def get_absolute_url(self):
  35                 root = Site.objects.get_current().root_node
  36                 try:
  37                         return '/%s' % self.get_path(root=root)
  38                 except AncestorDoesNotExist:
  39                         return None
  40
  41         class Meta:
  42                 app_label = 'philo'
  43
  44
  45 # the following line enables the selection of a node as the root for a given django.contrib.sites Site object
  46 models.ForeignKey(Node, related_name='sites', null=True, blank=True).contribute_to_class(Site, 'root_node')
  47
  48
  49 class View(Entity):
  50         nodes = generic.GenericRelation(Node, content_type_field='view_content_type', object_id_field='view_object_id')
  51
  52         accepts_subpath = False
  53
  54         def get_subpath(self, obj):
  55                 raise ViewDoesNotProvideSubpaths
  56
  57         def attributes_with_node(self, node):
  58                 return QuerySetMapper(self.attribute_set, passthrough=node.attributes)
  59
  60         def relationships_with_node(self, node):
  61                 return QuerySetMapper(self.relationship_set, passthrough=node.relationships)
  62
  63         def render_to_response(self, node, request, path=None, subpath=None, extra_context=None):
  64                 extra_context = extra_context or {}
  65                 view_about_to_render.send(sender=self, node=node, request=request, path=path, subpath=subpath, extra_context=extra_context)
  66                 response = self.actually_render_to_response(node, request, path, subpath, extra_context)
  67                 view_finished_rendering.send(sender=self, response=response)
  68                 return response
  69
  70         def actually_render_to_response(self, node, request, path=None, subpath=None, extra_context=None):
  71                 raise NotImplementedError('View subclasses must implement render_to_response.')
  72
  73         class Meta:
  74                 abstract = True
  75
  76
  77 _view_content_type_limiter.cls = View
  78
  79
  80 class MultiView(View):
  81         accepts_subpath = True
  82
  83         urlpatterns = []
  84
  85         def actually_render_to_response(self, node, request, path=None, subpath=None, extra_context=None):
  86                 clear_url_caches()
  87                 if not subpath:
  88                         subpath = ""
  89                 subpath = "/" + subpath
  90                 view, args, kwargs = resolve(subpath, urlconf=self)
  91                 view_args = getargspec(view)
  92                 if extra_context is not None and ('extra_context' in view_args[0] or view_args[2] is not None):
  93                         if 'extra_context' in kwargs:
  94                                 extra_context.update(kwargs['extra_context'])
  95                         kwargs['extra_context'] = extra_context
  96                 if 'node' in view_args[0] or view_args[2] is not None:
  97                         kwargs['node'] = node
  98                 return view(request, *args, **kwargs)
  99
 100         class Meta:
 101                 abstract = True
 102
 103
 104 class Redirect(View):
 105         STATUS_CODES = (
 106                 (302, 'Temporary'),
 107                 (301, 'Permanent'),
 108         )
 109         target = models.CharField(max_length=200, validators=[RedirectValidator()])
 110         status_code = models.IntegerField(choices=STATUS_CODES, default=302, verbose_name='redirect type')
 111
 112         def actually_render_to_response(self, node, request, path=None, subpath=None, extra_context=None):
 113                 response = HttpResponseRedirect(self.target)
 114                 response.status_code = self.status_code
 115                 return response
 116
 117         class Meta:
 118                 app_label = 'philo'
 119
 120
 121 class File(View):
 122         """ For storing arbitrary files """
 123
 124         mimetype = models.CharField(max_length=255)
 125         file = models.FileField(upload_to='philo/files/%Y/%m/%d')
 126
 127         def actually_render_to_response(self, node, request, path=None, subpath=None, extra_context=None):
 128                 wrapper = FileWrapper(self.file)
 129                 response = HttpResponse(wrapper, content_type=self.mimetype)
 130                 response['Content-Length'] = self.file.size
 131                 return response
 132
 133         class Meta:
 134                 app_label = 'philo'
 135
 136         def __unicode__(self):
 137                 return self.file.name
 138
 139
 140 register_templatetags('philo.templatetags.nodes')
 141 register_value_model(Node)