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