Fix deprecation warnings for Django 1.11 and Django 2.0.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/acls/models.py

@@ -30,7 +30,7 @@ class AccessControlList(models.Model):
     in the Setup menu.
     """
     content_type = models.ForeignKey(
-        ContentType,
+        ContentType, on_delete=models.CASCADE,
         related_name='object_content_type'
     )
     object_id = models.PositiveIntegerField()
@@ -43,7 +43,10 @@ class AccessControlList(models.Model):
         StoredPermission, blank=True, related_name='acls',
         verbose_name=_('Permissions')
     )
-    role = models.ForeignKey(Role, related_name='acls', verbose_name=_('Role'))
+    role = models.ForeignKey(
+        Role, on_delete=models.CASCADE, related_name='acls',
+        verbose_name=_('Role')
+    )
 
     objects = AccessControlListManager()
 

mayan/apps/acls/tests/test_api.py

@@ -2,8 +2,8 @@ from __future__ import absolute_import, unicode_literals
 
 from django.contrib.auth import get_user_model
 from django.contrib.contenttypes.models import ContentType
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from rest_framework.test import APITestCase
 

mayan/apps/acls/tests/test_links.py

@@ -1,7 +1,7 @@
 from __future__ import unicode_literals
 
 from django.contrib.contenttypes.models import ContentType
-from django.core.urlresolvers import reverse
+from django.urls import resolve, reverse
 
 from documents.tests.test_views import GenericDocumentViewTestCase
 from user_management.tests.literals import (

mayan/apps/acls/views.py

@@ -4,9 +4,9 @@ import itertools
 import logging
 
 from django.contrib.contenttypes.models import ContentType
-from django.core.urlresolvers import reverse
 from django.http import Http404, HttpResponseRedirect
 from django.shortcuts import get_object_or_404
+from django.urls import reverse
 from django.utils.encoding import force_text
 from django.utils.translation import ugettext_lazy as _
 

mayan/apps/authentication/tests/test_views.py

@@ -3,8 +3,8 @@ from __future__ import absolute_import, unicode_literals
 from django.conf import settings
 from django.contrib.auth import get_user_model
 from django.core import mail
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from common.tests import BaseTestCase
 from smart_settings.classes import Namespace

mayan/apps/authentication/views.py

@@ -6,10 +6,11 @@ from django.contrib.auth.views import (
     login, password_change, password_reset, password_reset_confirm,
     password_reset_complete, password_reset_done
 )
-from django.core.urlresolvers import reverse
 from django.http import HttpResponseRedirect
 from django.shortcuts import redirect
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
+
 from stronghold.decorators import public
 
 from .forms import EmailAuthenticationForm, UsernameAuthenticationForm
@@ -29,7 +30,7 @@ def login_view(request):
     else:
         kwargs['authentication_form'] = UsernameAuthenticationForm
 
-    if not request.user.is_authenticated():
+    if not request.user.is_authenticated:
         extra_context = {'appearance_type': 'plain'}
 
         result = login(request, extra_context=extra_context, **kwargs)

mayan/apps/cabinets/models.py

@@ -1,8 +1,8 @@
 from __future__ import absolute_import, unicode_literals
 
 from django.core.exceptions import NON_FIELD_ERRORS, ValidationError
-from django.core.urlresolvers import reverse
 from django.db import models, transaction
+from django.urls import reverse
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 
@@ -19,7 +19,8 @@ from .search import cabinet_search  # NOQA
 @python_2_unicode_compatible
 class Cabinet(MPTTModel):
     parent = TreeForeignKey(
-        'self', blank=True, db_index=True, null=True, related_name='children'
+        'self', blank=True, db_index=True, null=True,
+        on_delete=models.CASCADE, related_name='children'
     )
     label = models.CharField(max_length=128, verbose_name=_('Label'))
     documents = models.ManyToManyField(

mayan/apps/cabinets/tests/test_api.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 from django.utils.encoding import force_text
 
 from rest_framework.test import APITestCase

mayan/apps/cabinets/views.py

@@ -3,8 +3,8 @@ from __future__ import absolute_import, unicode_literals
 import logging
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse_lazy
 from django.shortcuts import get_object_or_404
+from django.urls import reverse_lazy
 from django.utils.translation import ugettext_lazy as _, ungettext
 
 from acls.models import AccessControlList

mayan/apps/checkouts/apps.py

@@ -5,8 +5,8 @@ from datetime import timedelta
 from kombu import Exchange, Queue
 
 from django.apps import apps
-from django.core.urlresolvers import reverse_lazy
 from django.db.models.signals import pre_save
+from django.urls import reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
 from acls import ModelPermission

mayan/apps/checkouts/models.py

@@ -4,8 +4,8 @@ import logging
 
 from django.conf import settings
 from django.core.exceptions import ValidationError
-from django.core.urlresolvers import reverse
 from django.db import models
+from django.urls import reverse
 from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.timezone import now
 from django.utils.translation import ugettext_lazy as _
@@ -24,7 +24,9 @@ class DocumentCheckout(models.Model):
     """
     Model to store the state and information of a document checkout
     """
-    document = models.OneToOneField(Document, verbose_name=_('Document'))
+    document = models.OneToOneField(
+        Document, on_delete=models.CASCADE, verbose_name=_('Document')
+    )
     checkout_datetime = models.DateTimeField(
         auto_now_add=True, verbose_name=_('Check out date and time')
     )
@@ -34,7 +36,10 @@ class DocumentCheckout(models.Model):
         ),
         verbose_name=_('Check out expiration date and time')
     )
-    user = models.ForeignKey(settings.AUTH_USER_MODEL, verbose_name=_('User'))
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL, on_delete=models.CASCADE,
+        verbose_name=_('User')
+    )
     block_new_version = models.BooleanField(
         default=True,
         help_text=_(
@@ -89,7 +94,9 @@ class DocumentCheckout(models.Model):
 
 
 class NewVersionBlock(models.Model):
-    document = models.ForeignKey(Document, verbose_name=_('Document'))
+    document = models.ForeignKey(
+        Document, on_delete=models.CASCADE, verbose_name=_('Document')
+    )
 
     objects = NewVersionBlockManager()
 

mayan/apps/checkouts/views.py

@@ -1,9 +1,9 @@
 from __future__ import absolute_import, unicode_literals
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 
 from documents.models import Document

mayan/apps/common/classes.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.apps import apps
-from django.core.urlresolvers import reverse
 from django.db import models
+from django.urls import reverse
 from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.translation import ugettext
 

mayan/apps/common/mixins.py

@@ -3,9 +3,9 @@ from __future__ import unicode_literals
 from django.conf import settings
 from django.contrib import messages
 from django.core.exceptions import PermissionDenied
-from django.core.urlresolvers import reverse
 from django.db.models.query import QuerySet
 from django.http import HttpResponseRedirect
+from django.urls import reverse
 from django.utils.translation import ungettext, ugettext_lazy as _
 
 from permissions import Permission

mayan/apps/common/models.py

@@ -49,8 +49,8 @@ class SharedUploadedFile(models.Model):
 @python_2_unicode_compatible
 class UserLocaleProfile(models.Model):
     user = models.OneToOneField(
-        settings.AUTH_USER_MODEL, related_name='locale_profile',
-        verbose_name=_('User')
+        settings.AUTH_USER_MODEL, on_delete=models.CASCADE,
+        related_name='locale_profile', verbose_name=_('User')
     )
     timezone = models.CharField(
         choices=zip(common_timezones, common_timezones), max_length=48,

mayan/apps/common/templatetags/common_tags.py

@@ -24,12 +24,12 @@ except sh.CommandNotFound:
     DATE = None
 
 
-@register.assignment_tag
+@register.simple_tag
 def get_collections():
     return Collection.get_all()
 
 
-@register.assignment_tag
+@register.simple_tag
 def get_dashboard_widgets():
     return DashboardWidget.get_all()
 
@@ -52,7 +52,7 @@ def project_copyright():
     return settings.PROJECT_COPYRIGHT
 
 
-@register.assignment_tag
+@register.simple_tag
 def project_description():
     return getattr(settings, 'PROJECT_DESCRIPTION', mayan.__description__)
 
@@ -77,7 +77,7 @@ def project_version():
     return mayan.__version__
 
 
-@register.assignment_tag(takes_context=True)
+@register.simple_tag(takes_context=True)
 def render_subtemplate(context, template_name, template_context):
     """
     Renders the specified template with the mixed parent and
@@ -89,7 +89,7 @@ def render_subtemplate(context, template_name, template_context):
     return get_template(template_name).render(new_context)
 
 
-@register.assignment_tag
+@register.simple_tag
 def build():
     if BUILD:
         try:

mayan/apps/common/tests/test_api.py

@@ -1,6 +1,6 @@
 from __future__ import unicode_literals
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from rest_api.tests import BaseAPITestCase
 

mayan/apps/common/tests/test_views.py

@@ -3,9 +3,9 @@ from __future__ import absolute_import, unicode_literals
 from django.conf.urls import url
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group
-from django.core.urlresolvers import clear_url_caches, reverse
 from django.http import HttpResponse
 from django.template import Context, Template
+from django.urls import clear_url_caches, reverse
 
 from acls.models import AccessControlList
 from permissions.models import Role
@@ -91,7 +91,7 @@ class GenericViewTestCase(BaseTestCase):
         user = get_user_model().objects.get(username=username)
 
         self.assertTrue(logged_in)
-        self.assertTrue(user.is_authenticated())
+        self.assertTrue(user.is_authenticated)
 
     def login_user(self):
         self.login(username=TEST_USER_USERNAME, password=TEST_USER_PASSWORD)

mayan/apps/common/utils.py

@@ -8,7 +8,7 @@ import types
 import xmlrpclib
 
 from django.conf import settings
-from django.core.urlresolvers import resolve as django_resolve
+from django.urls import resolve as django_resolve
 from django.urls.base import get_script_prefix
 from django.utils.datastructures import MultiValueDict
 from django.utils.encoding import force_text

mayan/apps/common/views.py

@@ -4,9 +4,9 @@ from json import dumps
 
 from django.conf import settings
 from django.contrib import messages
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.http import Http404, HttpResponseRedirect
 from django.template import RequestContext
+from django.urls import reverse, reverse_lazy
 from django.utils import timezone, translation
 from django.utils.http import urlencode
 from django.utils.translation import ugettext_lazy as _, ugettext

mayan/apps/converter/models.py

@@ -29,7 +29,7 @@ class Transformation(models.Model):
     transformation argument. Example: if a page is rotated with the Rotation
     transformation, this field will show by how many degrees it was rotated.
     """
-    content_type = models.ForeignKey(ContentType)
+    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
     object_id = models.PositiveIntegerField()
     content_object = GenericForeignKey('content_type', 'object_id')
 

mayan/apps/converter/views.py

@@ -3,9 +3,9 @@ from __future__ import absolute_import, unicode_literals
 import logging
 
 from django.contrib.contenttypes.models import ContentType
-from django.core.urlresolvers import reverse
 from django.http import Http404
 from django.shortcuts import get_object_or_404
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 
 from acls.models import AccessControlList

mayan/apps/django_gpg/models.py

@@ -4,8 +4,8 @@ from datetime import date
 import logging
 
 from django.core.exceptions import ValidationError
-from django.core.urlresolvers import reverse
 from django.db import models
+from django.urls import reverse
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 

mayan/apps/django_gpg/tests/test_api.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from rest_api.tests import BaseAPITestCase
 from user_management.tests.literals import (

mayan/apps/django_gpg/views.py

@@ -4,7 +4,7 @@ import logging
 
 from django.contrib import messages
 from django.core.files.base import ContentFile
-from django.core.urlresolvers import reverse, reverse_lazy
+from django.urls import reverse, reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
 from common.generics import (

mayan/apps/document_comments/models.py

@@ -19,12 +19,12 @@ logger = logging.getLogger(__name__)
 @python_2_unicode_compatible
 class Comment(models.Model):
     document = models.ForeignKey(
-        Document, db_index=True, related_name='comments',
-        verbose_name=_('Document')
+        Document, db_index=True, on_delete=models.CASCADE,
+        related_name='comments', verbose_name=_('Document')
     )
     user = models.ForeignKey(
-        settings.AUTH_USER_MODEL, editable=False, related_name='comments',
-        verbose_name=_('User'),
+        settings.AUTH_USER_MODEL, editable=False, on_delete=models.CASCADE,
+        related_name='comments', verbose_name=_('User'),
     )
     # Translators: Comment here is a noun and refers to the actual text stored
     comment = models.TextField(verbose_name=_('Comment'))

mayan/apps/document_comments/tests/test_api.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from rest_framework.test import APITestCase
 

mayan/apps/document_comments/views.py

@@ -1,7 +1,7 @@
 from __future__ import absolute_import, unicode_literals
 
-from django.core.urlresolvers import reverse
 from django.shortcuts import get_object_or_404
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 
 from acls.models import AccessControlList

mayan/apps/document_indexing/models.py

@@ -2,9 +2,9 @@ from __future__ import absolute_import, unicode_literals
 
 import logging
 
-from django.core.urlresolvers import reverse
 from django.db import models, transaction
 from django.template import Context, Template
+from django.urls import reverse
 from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.translation import ugettext, ugettext_lazy as _
 
@@ -145,9 +145,12 @@ class IndexTemplateNode(MPTTModel):
     hierarchy of levels. Each level can contain further levels or a list of
     documents but not both.
     """
-    parent = TreeForeignKey('self', blank=True, null=True)
+    parent = TreeForeignKey(
+        'self', blank=True, null=True, on_delete=models.CASCADE
+    )
     index = models.ForeignKey(
-        Index, related_name='node_templates', verbose_name=_('Index')
+        Index, on_delete=models.CASCADE, related_name='node_templates',
+        verbose_name=_('Index')
     )
     expression = models.TextField(
         help_text=_(
@@ -272,9 +275,12 @@ class IndexTemplateNode(MPTTModel):
 
 @python_2_unicode_compatible
 class IndexInstanceNode(MPTTModel):
-    parent = TreeForeignKey('self', null=True, blank=True)
+    parent = TreeForeignKey(
+        'self', blank=True, null=True, on_delete=models.CASCADE
+    )
     index_template_node = models.ForeignKey(
-        IndexTemplateNode, related_name='index_instance_nodes',
+        IndexTemplateNode, on_delete=models.CASCADE,
+        related_name='index_instance_nodes',
         verbose_name=_('Index template node')
     )
     value = models.CharField(

mayan/apps/document_indexing/views.py

@@ -1,8 +1,8 @@
 from __future__ import absolute_import, unicode_literals
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.shortcuts import get_object_or_404
+from django.urls import reverse, reverse_lazy
 from django.utils.html import mark_safe
 from django.utils.translation import ugettext_lazy as _
 

mayan/apps/document_signatures/models.py

@@ -3,8 +3,8 @@ from __future__ import unicode_literals
 import logging
 import uuid
 
-from django.core.urlresolvers import reverse
 from django.db import models
+from django.urls import reverse
 from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 
@@ -37,8 +37,8 @@ class SignatureBaseModel(models.Model):
     """
 
     document_version = models.ForeignKey(
-        DocumentVersion, editable=False, related_name='signatures',
-        verbose_name=_('Document version')
+        DocumentVersion, editable=False, on_delete=models.CASCADE,
+        related_name='signatures', verbose_name=_('Document version')
     )
     # Basic fields
     date = models.DateField(

mayan/apps/document_signatures/tests/test_links.py

@@ -1,7 +1,7 @@
 from __future__ import unicode_literals
 
 from django.core.files import File
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from documents.tests.literals import TEST_DOCUMENT_PATH
 from documents.tests.test_views import GenericDocumentViewTestCase

mayan/apps/document_signatures/views.py

@@ -4,9 +4,9 @@ import logging
 
 from django.contrib import messages
 from django.core.files import File
-from django.core.urlresolvers import reverse
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404
+from django.urls import reverse
 from django.utils.encoding import force_text
 from django.utils.translation import ugettext_lazy as _
 

mayan/apps/document_states/models.py

@@ -4,9 +4,9 @@ import logging
 
 from django.conf import settings
 from django.core.exceptions import PermissionDenied, ValidationError
-from django.core.urlresolvers import reverse
 from django.db import IntegrityError, models
 from django.db.models import F, Max, Q
+from django.urls import reverse
 from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 
@@ -90,7 +90,8 @@ class WorkflowState(models.Model):
     the Completion Amount will show 66%.
     """
     workflow = models.ForeignKey(
-        Workflow, related_name='states', verbose_name=_('Workflow')
+        Workflow, on_delete=models.CASCADE, related_name='states',
+        verbose_name=_('Workflow')
     )
     label = models.CharField(max_length=255, verbose_name=_('Label'))
     initial = models.BooleanField(
@@ -150,16 +151,18 @@ class WorkflowState(models.Model):
 @python_2_unicode_compatible
 class WorkflowTransition(models.Model):
     workflow = models.ForeignKey(
-        Workflow, related_name='transitions', verbose_name=_('Workflow')
+        Workflow, on_delete=models.CASCADE, related_name='transitions',
+        verbose_name=_('Workflow')
     )
     label = models.CharField(max_length=255, verbose_name=_('Label'))
 
     origin_state = models.ForeignKey(
-        WorkflowState, related_name='origin_transitions',
-        verbose_name=_('Origin state')
+        WorkflowState, on_delete=models.CASCADE,
+        related_name='origin_transitions', verbose_name=_('Origin state')
     )
     destination_state = models.ForeignKey(
-        WorkflowState, related_name='destination_transitions',
+        WorkflowState, on_delete=models.CASCADE,
+        related_name='destination_transitions',
         verbose_name=_('Destination state')
     )
 
@@ -178,10 +181,12 @@ class WorkflowTransition(models.Model):
 @python_2_unicode_compatible
 class WorkflowInstance(models.Model):
     workflow = models.ForeignKey(
-        Workflow, related_name='instances', verbose_name=_('Workflow')
+        Workflow, on_delete=models.CASCADE, related_name='instances',
+        verbose_name=_('Workflow')
     )
     document = models.ForeignKey(
-        Document, related_name='workflows', verbose_name=_('Document')
+        Document, on_delete=models.CASCADE, related_name='workflows',
+        verbose_name=_('Document')
     )
 
     def __str__(self):
@@ -290,16 +295,20 @@ class WorkflowInstanceLogEntry(models.Model):
     the document state to the Actual state.
     """
     workflow_instance = models.ForeignKey(
-        WorkflowInstance, related_name='log_entries',
-        verbose_name=_('Workflow instance')
+        WorkflowInstance, on_delete=models.CASCADE,
+        related_name='log_entries', verbose_name=_('Workflow instance')
     )
     datetime = models.DateTimeField(
         auto_now_add=True, db_index=True, verbose_name=_('Datetime')
     )
     transition = models.ForeignKey(
-        WorkflowTransition, verbose_name=_('Transition')
+        WorkflowTransition, on_delete=models.CASCADE,
+        verbose_name=_('Transition')
+    )
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL, on_delete=models.CASCADE,
+        verbose_name=_('User')
     )
-    user = models.ForeignKey(settings.AUTH_USER_MODEL, verbose_name=_('User'))
     comment = models.TextField(blank=True, verbose_name=_('Comment'))
 
     def __str__(self):

mayan/apps/document_states/tests/test_api.py

@@ -2,8 +2,8 @@ from __future__ import absolute_import, unicode_literals
 
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from rest_framework.test import APITestCase
 

mayan/apps/document_states/views.py

@@ -1,10 +1,10 @@
 from __future__ import absolute_import, unicode_literals
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.db.utils import IntegrityError
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404
+from django.urls import reverse, reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
 from acls.models import AccessControlList

mayan/apps/documents/apps.py

@@ -4,7 +4,7 @@ from datetime import timedelta
 
 from kombu import Exchange, Queue
 
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
 from acls import ModelPermission

mayan/apps/documents/managers.py

@@ -144,7 +144,7 @@ class PassthroughManager(models.Manager):
 
 class RecentDocumentManager(models.Manager):
     def add_document_for_user(self, user, document):
-        if user.is_authenticated():
+        if user.is_authenticated:
             new_recent, created = self.model.objects.get_or_create(
                 user=user, document=document
             )
@@ -160,7 +160,7 @@ class RecentDocumentManager(models.Manager):
     def get_for_user(self, user):
         document_model = apps.get_model('documents', 'document')
 
-        if user.is_authenticated():
+        if user.is_authenticated:
             return document_model.objects.filter(
                 recentdocument__user=user
             ).order_by('-recentdocument__datetime_accessed')

mayan/apps/documents/models.py

@@ -6,8 +6,8 @@ import uuid
 
 from django.conf import settings
 from django.core.files import File
-from django.core.urlresolvers import reverse
 from django.db import models, transaction
+from django.urls import reverse
 from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.timezone import now
 from django.utils.translation import ugettext, ugettext_lazy as _
@@ -150,7 +150,7 @@ class Document(models.Model):
 
     uuid = models.UUIDField(default=uuid.uuid4, editable=False)
     document_type = models.ForeignKey(
-        DocumentType, related_name='documents',
+        DocumentType, on_delete=models.CASCADE, related_name='documents',
         verbose_name=_('Document type')
     )
     label = models.CharField(
@@ -363,7 +363,8 @@ class DocumentVersion(models.Model):
         cls._post_save_hooks[order] = func
 
     document = models.ForeignKey(
-        Document, related_name='versions', verbose_name=_('Document')
+        Document, on_delete=models.CASCADE, related_name='versions',
+        verbose_name=_('Document')
     )
     timestamp = models.DateTimeField(
         auto_now_add=True, db_index=True, verbose_name=_('Timestamp')
@@ -648,7 +649,7 @@ class DocumentTypeFilename(models.Model):
     quick rename functionality
     """
     document_type = models.ForeignKey(
-        DocumentType, related_name='filenames',
+        DocumentType, on_delete=models.CASCADE, related_name='filenames',
         verbose_name=_('Document type')
     )
     filename = models.CharField(
@@ -672,7 +673,7 @@ class DocumentPage(models.Model):
     Model that describes a document version page
     """
     document_version = models.ForeignKey(
-        DocumentVersion, related_name='pages',
+        DocumentVersion, on_delete=models.CASCADE, related_name='pages',
         verbose_name=_('Document version')
     )
     page_number = models.PositiveIntegerField(
@@ -845,7 +846,7 @@ class DocumentPage(models.Model):
 
 class DocumentPageCachedImage(models.Model):
     document_page = models.ForeignKey(
-        DocumentPage, related_name='cached_images',
+        DocumentPage, on_delete=models.CASCADE, related_name='cached_images',
         verbose_name=_('Document page')
     )
     filename = models.CharField(max_length=128, verbose_name=_('Filename'))
@@ -874,10 +875,12 @@ class RecentDocument(models.Model):
     a given user
     """
     user = models.ForeignKey(
-        settings.AUTH_USER_MODEL, db_index=True, editable=False, verbose_name=_('User')
+        settings.AUTH_USER_MODEL, db_index=True, editable=False,
+        on_delete=models.CASCADE, verbose_name=_('User')
     )
     document = models.ForeignKey(
-        Document, editable=False, verbose_name=_('Document')
+        Document, editable=False, on_delete=models.CASCADE,
+        verbose_name=_('Document')
     )
     datetime_accessed = models.DateTimeField(
         auto_now=True, db_index=True, verbose_name=_('Accessed')
@@ -901,7 +904,8 @@ class RecentDocument(models.Model):
 @python_2_unicode_compatible
 class DuplicatedDocument(models.Model):
     document = models.ForeignKey(
-        Document, related_name='duplicates', verbose_name=_('Document')
+        Document, on_delete=models.CASCADE, related_name='duplicates',
+        verbose_name=_('Document')
     )
     documents = models.ManyToManyField(
         Document, verbose_name=_('Duplicated documents')

mayan/apps/documents/tests/test_api.py

@@ -7,8 +7,8 @@ import time
 from json import loads
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 from django.utils.encoding import force_text
 
 from django_downloadview import assert_download_response

mayan/apps/documents/tests/test_links.py

@@ -4,7 +4,7 @@ from __future__ import unicode_literals
 
 import time
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from acls.models import AccessControlList
 from user_management.tests.literals import (

mayan/apps/documents/views/document_page_views.py

@@ -5,8 +5,8 @@ import urlparse
 
 from django.conf import settings
 from django.contrib import messages
-from django.core.urlresolvers import reverse
 from django.shortcuts import get_object_or_404
+from django.urls import reverse
 from django.utils.http import urlencode
 from django.utils.translation import ugettext_lazy as _
 from django.views.generic import RedirectView

mayan/apps/documents/views/document_type_views.py

@@ -2,8 +2,8 @@ from __future__ import absolute_import, unicode_literals
 
 import logging
 
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.shortcuts import get_object_or_404
+from django.urls import reverse, reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
 from acls.models import AccessControlList

mayan/apps/documents/views/document_views.py

@@ -4,9 +4,9 @@ import logging
 
 from django.contrib import messages
 from django.core.exceptions import PermissionDenied
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404
+from django.urls import reverse, reverse_lazy
 from django.utils.encoding import force_text
 from django.utils.http import urlencode
 from django.utils.translation import ugettext_lazy as _, ungettext

mayan/apps/documents/widgets.py

@@ -1,7 +1,7 @@
 from __future__ import unicode_literals
 
 from django import forms
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.utils.encoding import force_text
 from django.utils.html import strip_tags
 from django.utils.http import urlencode

mayan/apps/dynamic_search/tests/test_api.py

@@ -3,8 +3,8 @@ from __future__ import unicode_literals
 from json import loads
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from documents.models import DocumentType
 from documents.search import document_search

mayan/apps/dynamic_search/views.py

@@ -2,7 +2,7 @@ from __future__ import unicode_literals
 
 import logging
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 from django.views.generic.base import RedirectView
 

mayan/apps/events/tests/test_api.py

@@ -1,6 +1,6 @@
 from __future__ import unicode_literals
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from rest_api.tests import BaseAPITestCase
 

mayan/apps/events/widgets.py

@@ -1,6 +1,6 @@
 from __future__ import unicode_literals
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.utils.safestring import mark_safe
 
 from .classes import Event

mayan/apps/folders/models.py

@@ -1,7 +1,7 @@
 from __future__ import absolute_import, unicode_literals
 
-from django.core.urlresolvers import reverse
 from django.db import models
+from django.urls import reverse
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 

mayan/apps/folders/tests/test_api.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from documents.models import DocumentType
 from documents.tests import TEST_DOCUMENT_TYPE, TEST_SMALL_DOCUMENT_PATH

mayan/apps/folders/views.py

@@ -3,8 +3,8 @@ from __future__ import absolute_import, unicode_literals
 import logging
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse_lazy
 from django.shortcuts import get_object_or_404
+from django.urls import reverse_lazy
 from django.utils.translation import ugettext_lazy as _, ungettext
 
 from acls.models import AccessControlList

mayan/apps/linking/models.py

@@ -102,7 +102,8 @@ class ResolvedSmartLink(SmartLink):
 @python_2_unicode_compatible
 class SmartLinkCondition(models.Model):
     smart_link = models.ForeignKey(
-        SmartLink, related_name='conditions', verbose_name=_('Smart link')
+        SmartLink, on_delete=models.CASCADE, related_name='conditions',
+        verbose_name=_('Smart link')
     )
     inclusion = models.CharField(
         choices=INCLUSION_CHOICES, default=INCLUSION_AND,

mayan/apps/linking/tests/test_api.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from documents.models import DocumentType
 from documents.tests.literals import (

mayan/apps/linking/views.py

@@ -3,8 +3,8 @@ from __future__ import absolute_import, unicode_literals
 import logging
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.shortcuts import get_object_or_404
+from django.urls import reverse, reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
 from acls.models import AccessControlList

mayan/apps/mailer/models.py

@@ -111,7 +111,8 @@ class UserMailer(models.Model):
 
 class UserMailerLogEntry(models.Model):
     user_mailer = models.ForeignKey(
-        UserMailer, related_name='error_log', verbose_name=_('User mailer')
+        UserMailer, on_delete=models.CASCADE, related_name='error_log',
+        verbose_name=_('User mailer')
     )
     datetime = models.DateTimeField(
         auto_now_add=True, editable=False, verbose_name=_('Date time')

mayan/apps/mailer/views.py

@@ -1,10 +1,10 @@
 from __future__ import absolute_import, unicode_literals
 
 from django.contrib.sites.models import Site
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.http import Http404, HttpResponseRedirect
 from django.shortcuts import get_object_or_404
 from django.template import Context, Template
+from django.urls import reverse, reverse_lazy
 from django.utils.html import strip_tags
 from django.utils.translation import ungettext, ugettext_lazy as _
 

mayan/apps/metadata/models.py

@@ -151,9 +151,12 @@ class DocumentMetadata(models.Model):
     """
 
     document = models.ForeignKey(
-        Document, related_name='metadata', verbose_name=_('Document')
+        Document, on_delete=models.CASCADE, related_name='metadata',
+        verbose_name=_('Document')
+    )
+    metadata_type = models.ForeignKey(
+        MetadataType, on_delete=models.CASCADE, verbose_name=_('Type')
     )
-    metadata_type = models.ForeignKey(MetadataType, verbose_name=_('Type'))
     value = models.CharField(
         blank=True, db_index=True, max_length=255, null=True,
         verbose_name=_('Value')
@@ -200,11 +203,12 @@ class DocumentMetadata(models.Model):
 @python_2_unicode_compatible
 class DocumentTypeMetadataType(models.Model):
     document_type = models.ForeignKey(
-        DocumentType, related_name='metadata',
+        DocumentType, on_delete=models.CASCADE, related_name='metadata',
         verbose_name=_('Document type')
     )
     metadata_type = models.ForeignKey(
-        MetadataType, verbose_name=_('Metadata type')
+        MetadataType, on_delete=models.CASCADE,
+        verbose_name=_('Metadata type')
     )
     required = models.BooleanField(default=False, verbose_name=_('Required'))
 

mayan/apps/metadata/tests/test_api.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from documents.models import DocumentType
 from documents.tests import TEST_DOCUMENT_TYPE_LABEL, TEST_SMALL_DOCUMENT_PATH

mayan/apps/metadata/views.py

@@ -3,9 +3,9 @@ from __future__ import absolute_import, unicode_literals
 from django.conf import settings
 from django.contrib import messages
 from django.core.exceptions import ValidationError
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404
+from django.urls import reverse, reverse_lazy
 from django.utils.encoding import force_text
 from django.utils.http import urlencode
 from django.utils.translation import ugettext_lazy as _, ungettext

mayan/apps/motd/tests/test_api.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 
 from rest_api.tests import BaseAPITestCase
 from user_management.tests.literals import (

mayan/apps/motd/views.py

@@ -2,7 +2,7 @@ from __future__ import absolute_import, unicode_literals
 
 import logging
 
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
 from common.views import (

mayan/apps/navigation/classes.py

@@ -8,9 +8,9 @@ import urlparse
 from django.apps import apps
 from django.conf import settings
 from django.core.exceptions import PermissionDenied
-from django.core.urlresolvers import resolve, reverse
 from django.template import VariableDoesNotExist, Variable
 from django.template.defaulttags import URLNode
+from django.urls import resolve, reverse
 from django.utils.encoding import force_text
 from django.utils.http import urlencode, urlquote
 

mayan/apps/navigation/templatetags/navigation_tags.py

@@ -8,12 +8,12 @@ from ..forms import MultiItemForm
 register = Library()
 
 
-@register.assignment_tag(takes_context=True)
+@register.simple_tag(takes_context=True)
 def get_menu_links(context, name, source=None):
     return Menu.get(name).resolve(context=context, source=source)
 
 
-@register.assignment_tag(takes_context=True)
+@register.simple_tag(takes_context=True)
 def get_menus_links(context, names, source=None):
     result = []
 

mayan/apps/navigation/tests/test_classes.py

@@ -1,7 +1,7 @@
 from __future__ import absolute_import, unicode_literals
 
-from django.core.urlresolvers import reverse
 from django.template import Context
+from django.urls import reverse
 
 from acls.models import AccessControlList
 from common.tests.literals import TEST_VIEW_NAME

mayan/apps/ocr/models.py

@@ -12,8 +12,8 @@ class DocumentTypeSettings(models.Model):
     Define for OCR for a specific document should behave
     """
     document_type = models.OneToOneField(
-        DocumentType, related_name='ocr_settings', unique=True,
-        verbose_name=_('Document type')
+        DocumentType, on_delete=models.CASCADE, related_name='ocr_settings',
+        unique=True, verbose_name=_('Document type')
     )
     auto_ocr = models.BooleanField(
         default=True,
@@ -28,7 +28,7 @@ class DocumentTypeSettings(models.Model):
 @python_2_unicode_compatible
 class DocumentVersionOCRError(models.Model):
     document_version = models.ForeignKey(
-        DocumentVersion, related_name='ocr_errors',
+        DocumentVersion, on_delete=models.CASCADE, related_name='ocr_errors',
         verbose_name=_('Document version')
     )
     datetime_submitted = models.DateTimeField(
@@ -51,7 +51,7 @@ class DocumentPageContent(models.Model):
     Model that describes a document page content
     """
     document_page = models.OneToOneField(
-        DocumentPage, related_name='ocr_content',
+        DocumentPage, on_delete=models.CASCADE, related_name='ocr_content',
         verbose_name=_('Document page')
     )
     content = models.TextField(blank=True, verbose_name=_('Content'))

mayan/apps/ocr/tests/test_api.py

@@ -3,7 +3,7 @@ from __future__ import unicode_literals
 import json
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from rest_framework import status
 

mayan/apps/ocr/views.py

@@ -1,9 +1,9 @@
 from __future__ import absolute_import, unicode_literals
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 
 from acls.models import AccessControlList

mayan/apps/permissions/models.py

@@ -3,8 +3,8 @@ from __future__ import unicode_literals
 import logging
 
 from django.contrib.auth.models import Group
-from django.core.urlresolvers import reverse
 from django.db import models
+from django.urls import reverse
 from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 

mayan/apps/permissions/tests/test_api.py

@@ -2,7 +2,7 @@ from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from rest_api.tests import BaseAPITestCase
 from user_management.tests.literals import (

mayan/apps/permissions/tests/test_views.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test.client import Client
+from django.urls import reverse
 
 from common.tests import BaseTestCase
 from user_management.tests import (
@@ -27,7 +27,7 @@ class PermissionsViewsTestCase(BaseTestCase):
             username=TEST_ADMIN_USERNAME, password=TEST_ADMIN_PASSWORD
         )
         self.assertTrue(logged_in)
-        self.assertTrue(self.admin_user.is_authenticated())
+        self.assertTrue(self.admin_user.is_authenticated)
 
     def test_role_creation_view(self):
         response = self.client.post(

mayan/apps/permissions/views.py

@@ -3,8 +3,8 @@ from __future__ import unicode_literals
 import itertools
 
 from django.contrib.auth.models import Group
-from django.core.urlresolvers import reverse_lazy
 from django.shortcuts import get_object_or_404
+from django.urls import reverse_lazy
 from django.utils.encoding import force_text
 from django.utils.translation import ugettext_lazy as _
 

mayan/apps/sources/models.py

@@ -419,7 +419,7 @@ class IntervalBaseModel(OutOfProcessSource):
         DocumentType,
         help_text=_(
             'Assign a document type to documents uploaded from this source.'
-        ),
+        ), on_delete=models.CASCADE,
         verbose_name=_('Document type')
     )
     uncompress = models.CharField(
@@ -509,14 +509,14 @@ class EmailBaseModel(IntervalBaseModel):
         MetadataType, blank=True, help_text=_(
             'Select a metadata type valid for the document type selected in '
             'which to store the email\'s subject.'
-        ), null=True, related_name='email_subject',
+        ), on_delete=models.CASCADE, null=True, related_name='email_subject',
         verbose_name=_('Subject metadata type')
     )
     from_metadata_type = models.ForeignKey(
         MetadataType, blank=True, help_text=_(
             'Select a metadata type valid for the document type selected in '
             'which to store the email\'s "from" value.'
-        ), null=True, related_name='email_from',
+        ), on_delete=models.CASCADE, null=True, related_name='email_from',
         verbose_name=_('From metadata type')
     )
     store_body = models.BooleanField(
@@ -767,7 +767,8 @@ class WatchFolderSource(IntervalBaseModel):
 
 class SourceLog(models.Model):
     source = models.ForeignKey(
-        Source, related_name='logs', verbose_name=_('Source')
+        Source, on_delete=models.CASCADE, related_name='logs',
+        verbose_name=_('Source')
     )
     datetime = models.DateTimeField(
         auto_now_add=True, editable=False, verbose_name=_('Date time')

mayan/apps/sources/views.py

@@ -1,9 +1,9 @@
 from __future__ import absolute_import, unicode_literals
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.http import HttpResponseRedirect, JsonResponse
 from django.shortcuts import get_object_or_404
+from django.urls import reverse, reverse_lazy
 from django.utils.encoding import force_text
 from django.utils.translation import ugettext_lazy as _
 
@@ -232,7 +232,7 @@ class UploadInteractiveView(UploadBaseView):
                 if forms['document_form'].cleaned_data['document_type_available_filenames']:
                     label = forms['document_form'].cleaned_data['document_type_available_filenames'].filename
 
-            if not self.request.user.is_anonymous():
+            if not self.request.user.is_anonymous:
                 user_id = self.request.user.pk
             else:
                 user_id = None
@@ -372,7 +372,7 @@ class UploadInteractiveVersionView(UploadBaseView):
             except Exception as exception:
                 messages.error(self.request, exception)
 
-            if not self.request.user.is_anonymous():
+            if not self.request.user.is_anonymous:
                 user_id = self.request.user.pk
             else:
                 user_id = None

mayan/apps/sources/wizards.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse
 from django.http import HttpResponseRedirect
+from django.urls import reverse
 from django.utils.encoding import force_text
 from django.utils.http import urlencode
 from django.utils.translation import ugettext_lazy as _

mayan/apps/statistics/views.py

@@ -1,7 +1,7 @@
 from __future__ import unicode_literals
 
-from django.core.urlresolvers import reverse
 from django.http import Http404
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 
 from common.generics import ConfirmView, SimpleView, SingleObjectListView

mayan/apps/tags/models.py

@@ -1,7 +1,7 @@
 from __future__ import absolute_import, unicode_literals
 
-from django.core.urlresolvers import reverse
 from django.db import models
+from django.urls import reverse
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 

mayan/apps/tags/tests/test_api.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
 from django.test import override_settings
+from django.urls import reverse
 from django.utils.encoding import force_text
 
 from documents.models import DocumentType

mayan/apps/tags/views.py

@@ -3,8 +3,8 @@ from __future__ import absolute_import, unicode_literals
 import logging
 
 from django.contrib import messages
-from django.core.urlresolvers import reverse_lazy
 from django.shortcuts import get_object_or_404
+from django.urls import reverse_lazy
 from django.utils.translation import ugettext_lazy as _, ungettext
 
 from acls.models import AccessControlList

mayan/apps/user_management/tests/test_api.py

@@ -2,7 +2,7 @@ from __future__ import unicode_literals
 
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from rest_api.tests import BaseAPITestCase
 

mayan/apps/user_management/views.py

@@ -4,9 +4,9 @@ from django.contrib import messages
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group
 from django.contrib.contenttypes.models import ContentType
-from django.core.urlresolvers import reverse, reverse_lazy
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404
+from django.urls import reverse, reverse_lazy
 from django.utils.translation import ungettext, ugettext_lazy as _
 
 from common.views import (