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.exceptions import ViewDoesNotExist
   7 from django.core.servers.basehttp import FileWrapper
   8 from django.core.urlresolvers import resolve, clear_url_caches, reverse, NoReverseMatch
   9 from django.template import add_to_builtins as register_templatetags
  10 from inspect import getargspec
  11 from philo.exceptions import MIDDLEWARE_NOT_CONFIGURED
  12 from philo.models.base import TreeEntity, Entity, QuerySetMapper, register_value_model
  13 from philo.utils import ContentTypeSubclassLimiter
  14 from philo.validators import RedirectValidator
  15 from philo.exceptions import ViewCanNotProvideSubpath, ViewDoesNotProvideSubpaths, AncestorDoesNotExist
  16 from philo.signals import view_about_to_render, view_finished_rendering
  17
  18
  19 _view_content_type_limiter = ContentTypeSubclassLimiter(None)
  20
  21
  22 class Node(TreeEntity):
  23         view_content_type = models.ForeignKey(ContentType, related_name='node_view_set', limit_choices_to=_view_content_type_limiter)
  24         view_object_id = models.PositiveIntegerField()
  25         view = generic.GenericForeignKey('view_content_type', 'view_object_id')
  26
  27         @property
  28         def accepts_subpath(self):
  29                 if self.view:
  30                         return self.view.accepts_subpath
  31                 return False
  32
  33         def render_to_response(self, request, extra_context=None):
  34                 return self.view.render_to_response(request, extra_context)
  35
  36         def get_absolute_url(self):
  37                 try:
  38                         root = Site.objects.get_current().root_node
  39                 except Site.DoesNotExist:
  40                         root = None
  41
  42                 try:
  43                         path = self.get_path(root=root)
  44                         if path:
  45                                 path += '/'
  46                         root_url = reverse('philo-root')
  47                         return '%s%s' % (root_url, path)
  48                 except AncestorDoesNotExist, ViewDoesNotExist:
  49                         return None
  50
  51         class Meta:
  52                 app_label = 'philo'
  53
  54
  55 # the following line enables the selection of a node as the root for a given django.contrib.sites Site object
  56 models.ForeignKey(Node, related_name='sites', null=True, blank=True).contribute_to_class(Site, 'root_node')
  57
  58
  59 class View(Entity):
  60         nodes = generic.GenericRelation(Node, content_type_field='view_content_type', object_id_field='view_object_id')
  61
  62         accepts_subpath = False
  63
  64         def get_subpath(self, obj):
  65                 if not self.accepts_subpath:
  66                         raise ViewDoesNotProvideSubpaths
  67
  68                 view_name, args, kwargs = self.get_reverse_params(obj)
  69                 try:
  70                         return reverse(view_name, args=args, kwargs=kwargs, urlconf=self)
  71                 except NoReverseMatch:
  72                         raise ViewCanNotProvideSubpath
  73
  74         def get_reverse_params(self, obj):
  75                 """This method should return a view_name, args, kwargs tuple suitable for reversing a url for the given obj using self as the urlconf."""
  76                 raise NotImplementedError("View subclasses must implement get_reverse_params to support subpaths.")
  77
  78         def attributes_with_node(self, node):
  79                 return QuerySetMapper(self.attribute_set, passthrough=node.attributes)
  80
  81         def render_to_response(self, request, extra_context=None):
  82                 if not hasattr(request, 'node'):
  83                         raise MIDDLEWARE_NOT_CONFIGURED
  84
  85                 extra_context = extra_context or {}
  86                 view_about_to_render.send(sender=self, request=request, extra_context=extra_context)
  87                 response = self.actually_render_to_response(request, extra_context)
  88                 view_finished_rendering.send(sender=self, response=response)
  89                 return response
  90
  91         def actually_render_to_response(self, request, extra_context=None):
  92                 raise NotImplementedError('View subclasses must implement render_to_response.')
  93
  94         class Meta:
  95                 abstract = True
  96
  97
  98 _view_content_type_limiter.cls = View
  99
 100
 101 class MultiView(View):
 102         accepts_subpath = True
 103
 104         @property
 105         def urlpatterns(self, obj):
 106                 raise NotImplementedError("MultiView subclasses must implement urlpatterns.")
 107
 108         def actually_render_to_response(self, request, extra_context=None):
 109                 clear_url_caches()
 110                 subpath = request.node.subpath
 111                 if not subpath:
 112                         subpath = ""
 113                 subpath = "/" + subpath
 114                 view, args, kwargs = resolve(subpath, urlconf=self)
 115                 view_args = getargspec(view)
 116                 if extra_context is not None and ('extra_context' in view_args[0] or view_args[2] is not None):
 117                         if 'extra_context' in kwargs:
 118                                 extra_context.update(kwargs['extra_context'])
 119                         kwargs['extra_context'] = extra_context
 120                 return view(request, *args, **kwargs)
 121
 122         class Meta:
 123                 abstract = True
 124
 125
 126 class Redirect(View):
 127         STATUS_CODES = (
 128                 (302, 'Temporary'),
 129                 (301, 'Permanent'),
 130         )
 131         target = models.CharField(max_length=200, validators=[RedirectValidator()])
 132         status_code = models.IntegerField(choices=STATUS_CODES, default=302, verbose_name='redirect type')
 133
 134         def actually_render_to_response(self, request, extra_context=None):
 135                 response = HttpResponseRedirect(self.target)
 136                 response.status_code = self.status_code
 137                 return response
 138
 139         class Meta:
 140                 app_label = 'philo'
 141
 142
 143 # Why does this exist?
 144 class File(View):
 145         """ For storing arbitrary files """
 146
 147         mimetype = models.CharField(max_length=255)
 148         file = models.FileField(upload_to='philo/files/%Y/%m/%d')
 149
 150         def actually_render_to_response(self, request, extra_context=None):
 151                 wrapper = FileWrapper(self.file)
 152                 response = HttpResponse(wrapper, content_type=self.mimetype)
 153                 response['Content-Length'] = self.file.size
 154                 return response
 155
 156         class Meta:
 157                 app_label = 'philo'
 158
 159         def __unicode__(self):
 160                 return self.file.name
 161
 162
 163 register_templatetags('philo.templatetags.nodes')
 164 register_value_model(Node)