Finalizing URLPath as an MPTT model and generic relations on Articles

wiki/admin.py

+from django.contrib import admin
+from django.contrib.contenttypes.generic import GenericTabularInline
+from mptt.admin import MPTTModelAdmin
+
+import models
+
+class ArticleObjectAdmin(GenericTabularInline):
+    model = models.ArticleForObject
+    extra = 1
+    max_num = 1
+
+class ArticleAdmin(admin.ModelAdmin):
+    pass
+
+class URLPathAdmin(MPTTModelAdmin):
+    inlines = [ArticleObjectAdmin]
+    list_filter = ('site',)
+    list_display = ('slug', 'article')
+
+admin.site.register(models.URLPath, URLPathAdmin)
+admin.site.register(models.Article, ArticleAdmin)
\ No newline at end of file

wiki/migrations/0001_initial.py

@@ -13,17 +13,27 @@ class Migration(SchemaMigration):
             ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
             ('title', self.gf('django.db.models.fields.CharField')(max_length=512)),
             ('current_revision', self.gf('django.db.models.fields.related.ForeignKey')(blank=True, related_name='current_set', null=True, to=orm['wiki.ArticleRevision'])),
+            ('owner', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['auth.User'], null=True, blank=True)),
+            ('group', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['auth.Group'], null=True, blank=True)),
+            ('group_read', self.gf('django.db.models.fields.BooleanField')(default=True)),
+            ('group_write', self.gf('django.db.models.fields.BooleanField')(default=True)),
+            ('other_read', self.gf('django.db.models.fields.BooleanField')(default=True)),
+            ('other_write', self.gf('django.db.models.fields.BooleanField')(default=True)),
         ))
         db.send_create_signal('wiki', ['Article'])
 
-        # Adding model 'ObjectForArticle'
-        db.create_table('wiki_objectforarticle', (
+        # Adding model 'ArticleForObject'
+        db.create_table('wiki_articleforobject', (
             ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
             ('article', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['wiki.Article'])),
-            ('content_type', self.gf('django.db.models.fields.related.ForeignKey')(related_name='content_type_set_for_objectforarticle', to=orm['contenttypes.ContentType'])),
-            ('object_pk', self.gf('django.db.models.fields.TextField')()),
+            ('content_type', self.gf('django.db.models.fields.related.ForeignKey')(related_name='content_type_set_for_articleforobject', to=orm['contenttypes.ContentType'])),
+            ('object_id', self.gf('django.db.models.fields.PositiveIntegerField')()),
+            ('has_parent_method', self.gf('django.db.models.fields.BooleanField')(default=False)),
         ))
-        db.send_create_signal('wiki', ['ObjectForArticle'])
+        db.send_create_signal('wiki', ['ArticleForObject'])
+
+        # Adding unique constraint on 'ArticleForObject', fields ['content_type', 'object_id']
+        db.create_unique('wiki_articleforobject', ['content_type_id', 'object_id'])
 
         # Adding model 'ArticleRevision'
         db.create_table('wiki_articlerevision', (
@@ -35,14 +45,15 @@ class Migration(SchemaMigration):
             ('redirect', self.gf('django.db.models.fields.related.ForeignKey')(blank=True, related_name='redirect_set', null=True, to=orm['wiki.Article'])),
             ('ip_address', self.gf('django.db.models.fields.IPAddressField')(max_length=15, null=True, blank=True)),
             ('user', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['auth.User'], null=True, blank=True)),
+            ('created', self.gf('django.db.models.fields.DateTimeField')(auto_now_add=True, blank=True)),
+            ('modified', self.gf('django.db.models.fields.DateTimeField')(auto_now=True, blank=True)),
         ))
         db.send_create_signal('wiki', ['ArticleRevision'])
 
         # Adding model 'URLPath'
         db.create_table('wiki_urlpath', (
             ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
-            ('article', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['wiki.Article'])),
-            ('slug', self.gf('django.db.models.fields.SlugField')(max_length=50)),
+            ('slug', self.gf('django.db.models.fields.SlugField')(max_length=50, null=True, blank=True)),
             ('site', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['sites.Site'])),
             ('parent', self.gf('mptt.fields.TreeForeignKey')(blank=True, related_name='children', null=True, to=orm['wiki.URLPath'])),
             ('lft', self.gf('django.db.models.fields.PositiveIntegerField')(db_index=True)),
@@ -59,11 +70,14 @@ class Migration(SchemaMigration):
         # Removing unique constraint on 'URLPath', fields ['site', 'parent', 'slug']
         db.delete_unique('wiki_urlpath', ['site_id', 'parent_id', 'slug'])
 
+        # Removing unique constraint on 'ArticleForObject', fields ['content_type', 'object_id']
+        db.delete_unique('wiki_articleforobject', ['content_type_id', 'object_id'])
+
         # Deleting model 'Article'
         db.delete_table('wiki_article')
 
-        # Deleting model 'ObjectForArticle'
-        db.delete_table('wiki_objectforarticle')
+        # Deleting model 'ArticleForObject'
+        db.delete_table('wiki_articleforobject')
 
         # Deleting model 'ArticleRevision'
         db.delete_table('wiki_articlerevision')
@@ -117,37 +131,45 @@ class Migration(SchemaMigration):
         'wiki.article': {
             'Meta': {'object_name': 'Article'},
             'current_revision': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'current_set'", 'null': 'True', 'to': "orm['wiki.ArticleRevision']"}),
+            'group': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.Group']", 'null': 'True', 'blank': 'True'}),
+            'group_read': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'group_write': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
             'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'other_read': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'other_write': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'owner': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']", 'null': 'True', 'blank': 'True'}),
             'title': ('django.db.models.fields.CharField', [], {'max_length': '512'})
         },
+        'wiki.articleforobject': {
+            'Meta': {'unique_together': "(('content_type', 'object_id'),)", 'object_name': 'ArticleForObject'},
+            'article': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['wiki.Article']"}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'content_type_set_for_articleforobject'", 'to': "orm['contenttypes.ContentType']"}),
+            'has_parent_method': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'object_id': ('django.db.models.fields.PositiveIntegerField', [], {})
+        },
         'wiki.articlerevision': {
             'Meta': {'object_name': 'ArticleRevision'},
             'article': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['wiki.Article']"}),
             'content': ('django.db.models.fields.TextField', [], {'blank': 'True'}),
+            'created': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
             'deleted': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
             'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
             'ip_address': ('django.db.models.fields.IPAddressField', [], {'max_length': '15', 'null': 'True', 'blank': 'True'}),
+            'modified': ('django.db.models.fields.DateTimeField', [], {'auto_now': 'True', 'blank': 'True'}),
             'redirect': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'redirect_set'", 'null': 'True', 'to': "orm['wiki.Article']"}),
             'revision_number': ('django.db.models.fields.IntegerField', [], {}),
             'user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']", 'null': 'True', 'blank': 'True'})
         },
-        'wiki.objectforarticle': {
-            'Meta': {'object_name': 'ObjectForArticle'},
-            'article': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['wiki.Article']"}),
-            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'content_type_set_for_objectforarticle'", 'to': "orm['contenttypes.ContentType']"}),
-            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'object_pk': ('django.db.models.fields.TextField', [], {})
-        },
         'wiki.urlpath': {
             'Meta': {'unique_together': "(('site', 'parent', 'slug'),)", 'object_name': 'URLPath'},
-            'article': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['wiki.Article']"}),
             'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
             'level': ('django.db.models.fields.PositiveIntegerField', [], {'db_index': 'True'}),
             'lft': ('django.db.models.fields.PositiveIntegerField', [], {'db_index': 'True'}),
             'parent': ('mptt.fields.TreeForeignKey', [], {'blank': 'True', 'related_name': "'children'", 'null': 'True', 'to': "orm['wiki.URLPath']"}),
             'rght': ('django.db.models.fields.PositiveIntegerField', [], {'db_index': 'True'}),
             'site': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['sites.Site']"}),
-            'slug': ('django.db.models.fields.SlugField', [], {'max_length': '50'}),
+            'slug': ('django.db.models.fields.SlugField', [], {'max_length': '50', 'null': 'True', 'blank': 'True'}),
             'tree_id': ('django.db.models.fields.PositiveIntegerField', [], {'db_index': 'True'})
         }
     }

wiki/models/__init__.py

@@ -4,7 +4,7 @@ from django.conf import settings as django_settings
 from django.core.exceptions import ImproperlyConfigured
 import warnings
 
-from article import Article, ArticleRevision, ObjectForArticle
+from article import Article, ArticleRevision, ArticleForObject
 from urlpath import URLPath
 
 ######################

wiki/models/article.py

@@ -15,15 +15,6 @@ class Article(models.Model):
                                          verbose_name=_(u'current revision'),
                                          blank=True, null=True, related_name='current_set')
     
-    # Permissions. If nothing is set, the article will inherit from
-    # some other parent, whatever the semantics dictate. For instance, using
-    # URLPaths means that the article inherits from its URLPath parent.
-    # Inheriting permissions requires a "get_parent_articles" method to exist on
-    # one of the objects related to the article.
-    
-    # TIP: The related object with a get_parent_articles method should be an 
-    # MPTTModel inheritor for efficiency. See the URLPath model.
-    
     owner = models.ForeignKey(User, verbose_name=_('owner'),
                               blank=True, null=True)
     
@@ -36,10 +27,53 @@ class Article(models.Model):
     other_write = models.BooleanField(default=True)
     
     def can_read(self, user=None, group=None):
-        return True
+        if self.other_read:
+            return True
+        if user == self.owner:
+            return True
+        if self.group_read:
+            if group == self.group:
+                return True
+            if self.group and user and user.groups.filter(group=group):
+                return True
+        return False
     
     def can_write(self, user=None, group=None):
-        return True
+        if self.other_write:
+            return True
+        if user == self.owner:
+            return True
+        if self.group_write:
+            if group == self.group:
+                return True
+            if self.group and user and user.groups.filter(group=group):
+                return True
+        return False
+    
+    def decendant_objects(self):
+        for obj in self.objectforarticle_set.filter(has_parent_field=True):
+            for decendant in obj.get_decendants():
+                yield decendant
+    
+    # All recursive permission methods will use decendant_objects to access
+    # generic relations and check if they are using MPTT and have INHERIT_PERMISSIONS=True
+    def set_permissions_recursive(self):
+        for decendant in self.decendant_objects():
+            if decendant.INHERIT_PERMISSIONS:
+                decendant.group_read = self.group_read
+                decendant.group_write = self.group_write
+                decendant.other_read = self.other_read
+                decendant.other_write = self.other_write
+    
+    def set_group_recursive(self):
+        for decendant in self.decendant_objects():
+            if decendant.INHERIT_PERMISSIONS:
+                decendant.group = self.group
+
+    def set_owner_recursive(self):
+        for decendant in self.decendant_objects():
+            if decendant.INHERIT_PERMISSIONS:
+                decendant.owner = self.owner
 
     def add_revision(self, new_revision, save=True):
         """
@@ -49,6 +83,7 @@ class Article(models.Model):
         assert self.id or save, ('Article.add_revision: Sorry, you cannot add a' 
                                  'revision to an article that has not been saved '
                                  'without using save=True')
+        if not self.id: self.save()
         revisions = self.articlerevision_set.all()
         try:
             new_revision.revision_number = revisions.latest().revision_number + 1
@@ -61,25 +96,40 @@ class Article(models.Model):
     
     def add_object_relation(self, obj):
         content_type = ContentType.objects.get_for_model(obj)
-        rel = ObjectForArticle.objects.get_or_create(article=self,
+        has_parent_field = hasattr(obj, 'parent')
+        rel = ArticleForObject.objects.get_or_create(article=self,
                                                      content_type=content_type,
-                                                     object_pk=obj.pk,)
+                                                     object_pk=obj.pk,
+                                                     has_parent_method=has_parent_field)
         return rel
     
+    @classmethod
+    def get_for_object(cls, obj):
+        return ArticleForObject.objects.get(object_id=obj.id, content_type=ContentType.objects.get_for_model(obj)).article
+    
+    def __unicode__(self):
+        return self.title
+    
     class Meta:
         app_label = settings.APP_LABEL
     
-class ObjectForArticle(models.Model):
+class ArticleForObject(models.Model):
     article = models.ForeignKey('Article')    
     # Same as django.contrib.comments
     content_type   = models.ForeignKey(ContentType,
                                        verbose_name=_('content type'),
                                        related_name="content_type_set_for_%(class)s")
-    object_pk      = models.TextField(_('object ID'))
-    content_object = generic.GenericForeignKey(ct_field="content_type", fk_field="object_pk")
+    object_id      = models.PositiveIntegerField(_('object ID'))
+    content_object = generic.GenericForeignKey(ct_field="content_type", fk_field="object_id")
+    
+    has_parent_method = models.BooleanField(default=False, editable=False)
     
     class Meta:
         app_label = settings.APP_LABEL
+        verbose_name = _(u'Article for object')
+        verbose_name_plural = _(u'Articles for object')
+        # Do not allow several objects
+        unique_together = ('content_type', 'object_id')
     
 class ArticleRevision(models.Model):
     

wiki/models/urlpath.py

 # -*- coding: utf-8 -*-
 from django.db import models
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import ugettext_lazy as _, ugettext
 from django.contrib.sites.models import Site
 from mptt.models import MPTTModel
 from mptt.fields import TreeForeignKey
@@ -8,15 +8,22 @@ from mptt.fields import TreeForeignKey
 from wiki.core.exceptions import NoRootURL, MultipleRootURLs
 from wiki.conf import settings
 
+from article import Article
+from wiki.models.article import ArticleRevision, ArticleForObject
+from django.contrib.contenttypes import generic
+from django.core.exceptions import ValidationError
+
 class URLPath(MPTTModel):
     """
     Strategy: Very few fields go here, as most has to be managed through an
     article's revision. As a side-effect, the URL resolution remains slim and swift.
     """
-    article = models.ForeignKey('wiki.Article',
-                                verbose_name=_(u'article'),
-                                help_text=_(u'Article to be displayed for this path'))
-    slug = models.SlugField(verbose_name=_(u'slug'))
+    # Tells django-wiki that permissions from a URLPath object's article
+    # should be inherited to children's articles
+    INHERIT_PERMISSIONS = True 
+    
+    articles = generic.GenericRelation(ArticleForObject)
+    slug = models.SlugField(verbose_name=_(u'slug'), null=True, blank=True)
     site = models.ForeignKey(Site)
     parent = TreeForeignKey('self', null=True, blank=True, related_name='children')    
     
@@ -24,10 +31,11 @@ class URLPath(MPTTModel):
         "/".join([obj.slug for obj in self.get_ancestors(include_self=True)])
 
     class MPTTMeta:
-        order_insertion_by = ['slug']
+        pass
     
     def __unicode__(self):
-        return self.path
+        path = self.get_path()
+        return path if path else ugettext(u"(root)")
     
     def save(self, *args, **kwargs):
         super(URLPath, self).save(*args, **kwargs)
@@ -37,7 +45,17 @@ class URLPath(MPTTModel):
         verbose_name_plural = _(u'URL paths')
         unique_together = ('site', 'parent', 'slug')
         app_label = settings.APP_LABEL
-        
+    
+    def clean(self, *args, **kwargs):
+        if self.slug and not self.parent:
+            raise ValidationError(_(u'Sorry but you cannot have a root article with a slug.'))
+        if not self.slug and self.parent:
+            raise ValidationError(_(u'A non-root note must always have a slug.'))
+        if not self.parent:
+            if URLPath.objects.root_nodes().filter(site=self.site):
+                raise ValidationError(_(u'There is already a root node on %s') % self.site)
+        super(URLPath, self).clean(*args, **kwargs)
+    
     @classmethod
     def get_by_path(cls, path):
         """
@@ -45,28 +63,44 @@ class URLPath(MPTTModel):
         Accepts paths both starting with and without '/'
         """
         site = Site.objects.get_current()
-        paths = cls.objects.filter(site=site)
-        root_nodes = paths.filter(parent=None)
+        root_nodes = cls.objects.root_nodes().filter(site=site)
         path = path.lstrip("/")
         
+        no_paths = root_nodes.count()
+        if no_paths == 0:
+            raise NoRootURL
+        if no_paths > 1:
+            raise MultipleRootURLs
         # Root page requested
         if not path:
-            no_paths = root_nodes.count()
-            if no_paths == 0:
-                raise NoRootURL
-            if no_paths > 1:
-                raise MultipleRootURLs
             return root_nodes[0]
         
         slugs = path.split('/')
+        level = 1
+        parent = root_nodes[0]
         for slug in slugs:
             if settings.URL_CASE_SENSITIVE:
-                paths = paths.filter(parent__slug=slug)
+                parent = parent.get_children.get(slug=slug)
             else:
-                paths = paths.filter(parent__slug__iexact=slug)
+                parent = parent.get_children.get(slug__iexact=slug)
+            level += 1
         
-        if paths.count() == 0:
-            raise cls.DoesNotExist
-        
-        return paths[0]
-        
+        return parent
+    
+    @classmethod
+    def create_root(cls, site=None):
+        if not site: site = Site.objects.get_current()
\ No newline at end of file
+        if not cls.objects.root_nodes().filter(site=site):
+            # (get_or_create does not work for MPTT models??)
+            root = cls.objects.create(site=site)
+            article = Article()
+            article.add_revision(ArticleRevision(), save=True)
+            article.add_object_relation(root)
+    
+    @property
+    def article(self):
+        try:
+            return self.articles.all()[0]
+        except IndexError:
+            return None
+    
\ No newline at end of file