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.models.fields import JSONField
  14 from philo.utils import ContentTypeSubclassLimiter
  15 from philo.validators import RedirectValidator
  16 from philo.exceptions import ViewCanNotProvideSubpath, ViewDoesNotProvideSubpaths, AncestorDoesNotExist
  17 from philo.signals import view_about_to_render, view_finished_rendering
  18 from mptt.templatetags.mptt_tags import cache_tree_children
  19
  20
  21 _view_content_type_limiter = ContentTypeSubclassLimiter(None)
  22 DEFAULT_NAVIGATION_DEPTH = 3
  23
  24
  25 class Node(TreeEntity):
  26         view_content_type = models.ForeignKey(ContentType, related_name='node_view_set', limit_choices_to=_view_content_type_limiter)
  27         view_object_id = models.PositiveIntegerField()
  28         view = generic.GenericForeignKey('view_content_type', 'view_object_id')
  29
  30         @property
  31         def accepts_subpath(self):
  32                 if self.view:
  33                         return self.view.accepts_subpath
  34                 return False
  35
  36         def render_to_response(self, request, extra_context=None):
  37                 return self.view.render_to_response(request, extra_context)
  38
  39         def get_absolute_url(self):
  40                 try:
  41                         root = Site.objects.get_current().root_node
  42                 except Site.DoesNotExist:
  43                         root = None
  44
  45                 try:
  46                         path = self.get_path(root=root)
  47                         if path:
  48                                 path += '/'
  49                         root_url = reverse('philo-root')
  50                         return '%s%s' % (root_url, path)
  51                 except AncestorDoesNotExist, ViewDoesNotExist:
  52                         return None
  53
  54         def get_navigation(self, depth=DEFAULT_NAVIGATION_DEPTH):
  55                 max_depth = depth + self.get_level()
  56                 tree = cache_tree_children(self.get_descendants(include_self=True).filter(level__lte=max_depth))
  57
  58                 def get_nav(parent, nodes):
  59                         node_overrides = dict([(override.child.pk, override) for override in NodeNavigationOverride.objects.filter(parent=parent, child__in=nodes).select_related('child')])
  60
  61                         navigation_list = []
  62
  63                         for node in nodes:
  64                                 node._override = node_overrides.get(node.pk, None)
  65
  66                                 if node._override:
  67                                         if node._override.hide:
  68                                                 continue
  69                                         navigation = node._override.get_navigation(node, max_depth)
  70                                 else:
  71                                         navigation = node.view.get_navigation(node, max_depth)
  72
  73                                 if not node.is_leaf_node() and node.get_level() < max_depth:
  74                                         children = navigation.get('children', [])
  75                                         children += get_nav(node, node.get_children())
  76                                         navigation['children'] = children
  77
  78                                 if 'children' in navigation:
  79                                         navigation['children'].sort(cmp=lambda x,y: cmp(x['order'], y['order']))
  80
  81                                 navigation_list.append(navigation)
  82
  83                         return navigation_list
  84
  85                 return get_nav(self.parent, tree)
  86
  87         def save(self):
  88                 super(Node, self).save()
  89
  90
  91         class Meta:
  92                 app_label = 'philo'
  93
  94
  95 # the following line enables the selection of a node as the root for a given django.contrib.sites Site object
  96 models.ForeignKey(Node, related_name='sites', null=True, blank=True).contribute_to_class(Site, 'root_node')
  97
  98
  99 class NodeNavigationOverride(Entity):
 100         parent = models.ForeignKey(Node, related_name="child_navigation_overrides", blank=True, null=True)
 101         child = models.ForeignKey(Node, related_name="navigation_overrides")
 102
 103         title = models.CharField(max_length=100, blank=True)
 104         url = models.CharField(max_length=200, validators=[RedirectValidator()], blank=True)
 105         order = models.PositiveSmallIntegerField(blank=True, null=True)
 106         child_navigation = JSONField()
 107         hide = models.BooleanField()
 108
 109         def get_navigation(self, node, depth, current_depth):
 110                 if self.child_navigation:
 111                         depth = current_depth
 112                 default = node.view.get_navigation(depth, current_depth)
 113                 if self.url:
 114                         default['url'] = self.url
 115                 if self.title:
 116                         default['title'] = self.title
 117                 if self.order:
 118                         default['order'] = self.order
 119                 if isinstance(self.child_navigation, list):
 120                         if 'children' in default:
 121                                 default['children'] += self.child_navigation
 122                         else:
 123                                 default['children'] = self.child_navigation
 124                 return default
 125
 126         class Meta:
 127                 ordering = ['order']
 128                 unique_together = ('parent', 'child',)
 129                 app_label = 'philo'
 130
 131
 132 class View(Entity):
 133         nodes = generic.GenericRelation(Node, content_type_field='view_content_type', object_id_field='view_object_id')
 134
 135         accepts_subpath = False
 136
 137         def get_subpath(self, obj):
 138                 if not self.accepts_subpath:
 139                         raise ViewDoesNotProvideSubpaths
 140
 141                 view_name, args, kwargs = self.get_reverse_params(obj)
 142                 try:
 143                         return reverse(view_name, args=args, kwargs=kwargs, urlconf=self)
 144                 except NoReverseMatch:
 145                         raise ViewCanNotProvideSubpath
 146
 147         def get_reverse_params(self, obj):
 148                 """This method should return a view_name, args, kwargs tuple suitable for reversing a url for the given obj using self as the urlconf."""
 149                 raise NotImplementedError("View subclasses must implement get_reverse_params to support subpaths.")
 150
 151         def attributes_with_node(self, node):
 152                 return QuerySetMapper(self.attribute_set, passthrough=node.attributes)
 153
 154         def render_to_response(self, request, extra_context=None):
 155                 if not hasattr(request, 'node'):
 156                         raise MIDDLEWARE_NOT_CONFIGURED
 157
 158                 extra_context = extra_context or {}
 159                 view_about_to_render.send(sender=self, request=request, extra_context=extra_context)
 160                 response = self.actually_render_to_response(request, extra_context)
 161                 view_finished_rendering.send(sender=self, response=response)
 162                 return response
 163
 164         def actually_render_to_response(self, request, extra_context=None):
 165                 raise NotImplementedError('View subclasses must implement render_to_response.')
 166
 167         def get_navigation(self, node, max_depth):
 168                 """
 169                 Subclasses should implement get_navigation to support auto-generated navigation.
 170                 max_depth is the deepest `level` that should be generated; node is the node that
 171                 is asking for the navigation. This method should return a dictionary of the form:
 172                         {
 173                                 'url': url,
 174                                 'title': title,
 175                                 'order': order, # None for no ordering.
 176                                 'children': [ # Optional
 177                                         <similar child navigation dictionaries>
 178                                 ]
 179                         }
 180                 """
 181                 raise NotImplementedError('View subclasses must implement get_navigation.')
 182
 183         class Meta:
 184                 abstract = True
 185
 186
 187 _view_content_type_limiter.cls = View
 188
 189
 190 class MultiView(View):
 191         accepts_subpath = True
 192
 193         @property
 194         def urlpatterns(self, obj):
 195                 raise NotImplementedError("MultiView subclasses must implement urlpatterns.")
 196
 197         def actually_render_to_response(self, request, extra_context=None):
 198                 clear_url_caches()
 199                 subpath = request.node.subpath
 200                 if not subpath:
 201                         subpath = ""
 202                 subpath = "/" + subpath
 203                 view, args, kwargs = resolve(subpath, urlconf=self)
 204                 view_args = getargspec(view)
 205                 if extra_context is not None and ('extra_context' in view_args[0] or view_args[2] is not None):
 206                         if 'extra_context' in kwargs:
 207                                 extra_context.update(kwargs['extra_context'])
 208                         kwargs['extra_context'] = extra_context
 209                 return view(request, *args, **kwargs)
 210
 211         class Meta:
 212                 abstract = True
 213
 214
 215 class Redirect(View):
 216         STATUS_CODES = (
 217                 (302, 'Temporary'),
 218                 (301, 'Permanent'),
 219         )
 220         target = models.CharField(max_length=200, validators=[RedirectValidator()])
 221         status_code = models.IntegerField(choices=STATUS_CODES, default=302, verbose_name='redirect type')
 222
 223         def actually_render_to_response(self, request, extra_context=None):
 224                 response = HttpResponseRedirect(self.target)
 225                 response.status_code = self.status_code
 226                 return response
 227
 228         class Meta:
 229                 app_label = 'philo'
 230
 231
 232 # Why does this exist?
 233 class File(View):
 234         """ For storing arbitrary files """
 235
 236         mimetype = models.CharField(max_length=255)
 237         file = models.FileField(upload_to='philo/files/%Y/%m/%d')
 238
 239         def actually_render_to_response(self, request, extra_context=None):
 240                 wrapper = FileWrapper(self.file)
 241                 response = HttpResponse(wrapper, content_type=self.mimetype)
 242                 response['Content-Length'] = self.file.size
 243                 return response
 244
 245         class Meta:
 246                 app_label = 'philo'
 247
 248         def __unicode__(self):
 249                 return self.file.name
 250
 251
 252 register_templatetags('philo.templatetags.nodes')
 253 register_value_model(Node)