Merge pull request #893 from ubyssey/peter/888-duplicate-head

Peter/888 duplicate head

dispatch/api/fields.py

@@ -4,15 +4,28 @@
 from rest_framework.exceptions import ValidationError
 
 class JSONField(Field):
-
     def to_internal_value(self, data):
         return data
 
     def to_representation(self, value):
         return value
 
-class PrimaryKeyField(Field):
+class NullBooleanField(Field):
+    """Forces a Django NullBooleanField to always return False for null values."""
+
+    def get_attribute(self, instance):
+        """Overrides the default get_attribute method to convert None values to False."""
 
+        attr = super(NullBooleanField, self).get_attribute(instance)
+        return True if attr else False
+
+    def to_internal_value(self, data):
+        return True if data else None
+
+    def to_representation(self, value):
+        return True if value else False
+
+class PrimaryKeyField(Field):
     def __init__(self, serializer, *args, **kwargs):
         super(PrimaryKeyField, self).__init__(*args, **kwargs)
 

dispatch/api/serializers.py

@@ -18,7 +18,7 @@
 from dispatch.api.validators import (
     FilenameValidator, ImageGalleryValidator, PasswordValidator,
     SlugValidator, AuthorValidator, TemplateValidator)
-from dispatch.api.fields import JSONField, PrimaryKeyField, ForeignKeyField
+from dispatch.api.fields import JSONField, NullBooleanField, PrimaryKeyField, ForeignKeyField
 
 class PersonSerializer(DispatchModelSerializer):
     """Serializes the Person model."""
@@ -608,6 +608,8 @@ class ArticleSerializer(DispatchModelSerializer, DispatchPublishableSerializer):
     id = serializers.ReadOnlyField(source='parent_id')
     slug = serializers.SlugField(validators=[SlugValidator()])
 
+    is_published = NullBooleanField(read_only=True)
+
     section = SectionSerializer(read_only=True)
     section_id = serializers.IntegerField(write_only=True)
 
@@ -770,6 +772,8 @@ class PageSerializer(DispatchModelSerializer, DispatchPublishableSerializer):
     id = serializers.ReadOnlyField(source='parent_id')
     slug = serializers.SlugField(validators=[SlugValidator()])
 
+    is_published = NullBooleanField(read_only=True)
+
     featured_image = ImageAttachmentSerializer(required=False, allow_null=True)
     featured_video = VideoAttachmentSerializer(required=False, allow_null=True)
 

dispatch/migrations/0022_publishable_constraints.py

@@ -0,0 +1,93 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11 on 2018-10-30 18:59
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+from dispatch.models import Article, Page
+
+def fix_latest_head(model, item):
+    latest = model.objects. \
+        filter(parent=item.parent). \
+        order_by('-id')[0]
+
+    model.objects. \
+        filter(parent=item.parent). \
+        update(head=None)
+
+    latest.head = True
+    latest.save(revision=False)
+
+    duplicates = model.objects. \
+        filter(slug=item.slug). \
+        exclude(parent=item.parent). \
+        delete()
+
+def fix_latest_published(model, item):
+    latest_items = model.objects. \
+        filter(parent_id=item.parent_id, is_published=True). \
+        order_by('-id')
+
+    if not latest_items:
+        return
+
+    model.objects. \
+        filter(parent=item.parent). \
+        update(is_published=None)
+
+    latest = latest_items[0]
+    latest.is_published = True
+    latest.save(revision=False)
+
+def fix_items(model):
+    seen = set()
+    for item in model.objects.order_by('-id'):
+        if item.slug in seen:
+            continue
+
+        fix_latest_head(model, item)
+        fix_latest_published(model, item)
+
+        seen.add(item.slug)
+
+def remove_duplicates(apps, schema_editor):
+    fix_items(Article)
+    fix_items(Page)
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dispatch', '0021_podcast_fields'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='article',
+            name='head',
+            field=models.NullBooleanField(db_index=True, default=False),
+        ),
+        migrations.AlterField(
+            model_name='article',
+            name='is_published',
+            field=models.NullBooleanField(db_index=True, default=False),
+        ),
+        migrations.AlterField(
+            model_name='page',
+            name='head',
+            field=models.NullBooleanField(db_index=True, default=False),
+        ),
+        migrations.AlterField(
+            model_name='page',
+            name='is_published',
+            field=models.NullBooleanField(db_index=True, default=False),
+        ),
+        migrations.RunPython(remove_duplicates),
+        migrations.AlterUniqueTogether(
+            name='article',
+            unique_together=set([('parent', 'slug', 'is_published'), ('slug', 'head'), ('parent', 'slug', 'head')]),
+        ),
+        migrations.AlterUniqueTogether(
+            name='page',
+            unique_together=set([('parent', 'slug', 'is_published'), ('slug', 'head'), ('parent', 'slug', 'head')]),
+        ),
+    ]

dispatch/modules/content/models.py

@@ -12,8 +12,8 @@
 
 from django.db.models import (
     Model, DateTimeField, CharField, TextField, PositiveIntegerField,
-    ImageField, FileField, BooleanField, UUIDField, ForeignKey,
-    ManyToManyField, SlugField, SET_NULL, CASCADE, F)
+    ImageField, FileField, BooleanField, NullBooleanField, UUIDField, 
+    ForeignKey, ManyToManyField, SlugField, SET_NULL, CASCADE, F)
 from django.conf import settings
 from django.core.validators import MaxValueValidator
 from django.utils import timezone
@@ -70,10 +70,10 @@ class Publishable(Model):
 
     preview_id = UUIDField(default=uuid.uuid4)
     revision_id = PositiveIntegerField(default=0, db_index=True)
-    head = BooleanField(default=False, db_index=True)
+    head = NullBooleanField(default=None, db_index=True, null=True)
 
-    is_published = BooleanField(default=False, db_index=True)
-    is_active = BooleanField(default=True)
+    is_published = NullBooleanField(default=None, db_index=True)
+    is_active = NullBooleanField(default=True)
 
     published_version = PositiveIntegerField(null=True)
     latest_version = PositiveIntegerField(null=True)
@@ -143,7 +143,7 @@ def is_parent(self):
 
     def publish(self):
         # Unpublish last published version
-        type(self).objects.filter(parent=self.parent, is_published=True).update(is_published=False, published_at=None)
+        type(self).objects.filter(parent=self.parent, is_published=True).update(is_published=None, published_at=None)
         self.is_published = True
         if self.published_at is None:
             self.published_at = timezone.now()
@@ -156,8 +156,8 @@ def publish(self):
         return self
 
     def unpublish(self):
-        type(self).objects.filter(parent=self.parent, is_published=True).update(is_published=False, published_at=None)
-        self.is_published = False
+        type(self).objects.filter(parent=self.parent, is_published=True).update(is_published=None, published_at=None)
+        self.is_published = None
 
         # Unset published version for all articles
         type(self).objects.filter(parent=self.parent).update(published_version=None)
@@ -184,19 +184,17 @@ def save(self, revision=True, *args, **kwargs):
 
             if not self.is_parent():
                 # If this is a revision, delete the old head of the list.
-                type(self).objects.filter(parent=self.parent, head=True).update(head=False)
+                type(self).objects \
+                    .filter(parent=self.parent, head=True) \
+                    .update(head=None)
 
                 # Clear the instance id to force Django to save a new instance.
                 # Both fields (pk, id) required for this to work -- something to do with model inheritance
                 self.pk = None
                 self.id = None
 
                 # New version is unpublished by default
-                self.is_published = False
-
-        # Raise integrity error if instance with given slug already exists.
-        if type(self).objects.filter(slug=self.slug).exclude(parent=self.parent).exists():
-            raise IntegrityError("%s with slug '%s' already exists." % (type(self).__name__, self.slug))
+                self.is_published = None
 
         # Set created_at to current time, but only for first version
         if not self.created_at:
@@ -206,14 +204,6 @@ def save(self, revision=True, *args, **kwargs):
         if revision:
             self.updated_at = timezone.now()
 
-        # Check that there is only one 'head'
-        if self.is_conflicting_head():
-            raise IntegrityError("%s with head=True already exists." % (type(self).__name__,))
-
-        # Check that there is only one version with this revision_id
-        if self.is_conflicting_revision_id():
-            raise IntegrityError("%s with revision_id=%s already exists." % (self.revision_id, type(self).__name__))
-
         super(Publishable, self).save(*args, **kwargs)
 
         # Update the parent foreign key
@@ -223,7 +213,10 @@ def save(self, revision=True, *args, **kwargs):
 
         if revision:
             # Set latest version for all articles
-            type(self).objects.filter(parent=self.parent).update(latest_version=self.revision_id)
+            type(self).objects \
+                .filter(parent=self.parent) \
+                .update(latest_version=self.revision_id)
+
             self.latest_version = self.revision_id
 
         return self
@@ -232,14 +225,9 @@ def save(self, revision=True, *args, **kwargs):
     def delete(self, *args, **kwargs):
         if self.parent == self:
             return super(Publishable, self).delete(*args, **kwargs)
+
         return self.parent.delete()
 
-    def is_conflicting_head(self):
-        return self.head is True and type(self).objects.filter(parent=self.parent, head=True).exclude(id=self.id).exists()
-
-    def is_conflicting_revision_id(self):
-        return type(self).objects.filter(parent=self.parent, id=self.id).count() > 1
-
     def save_featured_image(self, data):
         """
         Handles saving the featured image.
@@ -321,7 +309,9 @@ def get_previous_revision(self):
         if self.parent == self:
             return self
         try:
-            revision = type(self).objects.filter(parent=self.parent).order_by('-pk')[1]
+            revision = type(self).objects \
+                .filter(parent=self.parent) \
+                .order_by('-pk')[1]
             return revision
         except:
             return self
@@ -330,7 +320,6 @@ class Meta:
         abstract = True
 
 class Article(Publishable, AuthorMixin):
-
     parent = ForeignKey('Article', related_name='article_parent', blank=True, null=True)
 
     headline = CharField(max_length=255)
@@ -356,6 +345,13 @@ class Article(Publishable, AuthorMixin):
 
     reading_time = CharField(max_length=100, choices=READING_CHOICES, default='anytime')
 
+    class Meta:
+        unique_together = (
+            ('slug', 'head'),
+            ('parent', 'slug', 'head'),
+            ('parent', 'slug', 'is_published'),
+        )
+
     AuthorModel = Author
 
     @property
@@ -433,14 +429,21 @@ def get_published_articles(self):
         return Article.objects.filter(subsection=self, is_published=True).order_by('-published_at')
 
     def get_absolute_url(self):
-        """ Returns the subsection URL. """
+        """Returns the subsection URL."""
         return "%s%s/" % (settings.BASE_URL, self.slug)
 
 class Page(Publishable):
     parent = ForeignKey('Page', related_name='page_parent', blank=True, null=True)
     parent_page = ForeignKey('Page', related_name='parent_page_fk', null=True)
     title = CharField(max_length=255)
 
+    class Meta:
+        unique_together = (
+            ('slug', 'head'),
+            ('parent', 'slug', 'head'),
+            ('parent', 'slug', 'is_published'),
+        )
+
     def get_author_string(self):
         return None