Recalculate a document's indexes when attaching or removing a tag from or to it. Recalculate all of a tag's documents when a tag is about to be deleted.

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

HISTORY.rst

@@ -176,6 +176,8 @@
 - Don't provide a default for the scanner source adf_mode. Some scanners throw an error even when the selection
   if supported.
 - Add a "Quick Download" action to reduce the number of steps to download a single document. GitLab issue #338.
+- Recalculate a document's indexes when attaching or removing a tag from or to it.
+- Recalculate all of a tag's documents when a tag is about to be deleted.
 
 2.7.3 (2017-09-11)
 ==================

docs/releases/3.0.rst

@@ -522,6 +522,8 @@ Other changes worth mentioning
 - Don't provide a default for the scanner source adf_mode. Some scanners throw an error even when the selection
   if supported.
 - Add a "Quick Download" action to reduce the number of steps to download a single document. GitLab issue #338.
+- Recalculate a document's indexes when attaching or removing a tag from or to it.
+- Recalculate all of a tag's documents when a tag is about to be deleted.
 
 Removals
 --------

mayan/apps/tags/apps.py

@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 
 from django.apps import apps
+from django.db.models.signals import m2m_changed, pre_delete
 from django.utils.translation import ugettext_lazy as _
 
 from acls import ModelPermission
@@ -13,6 +14,7 @@ from common import (
 from documents.search import document_page_search, document_search
 from navigation import SourceColumn
 
+from .handlers import handler_index_document, handler_tag_pre_delete
 from .links import (
     link_multiple_documents_attach_tag, link_multiple_documents_tag_remove,
     link_single_document_multiple_tag_remove, link_tag_attach, link_tag_create,
@@ -149,3 +151,17 @@ class TagsApp(MayanAppConfig):
             )
         )
         registry.register(Tag)
+
+        # Index update
+
+        m2m_changed.connect(
+            handler_index_document,
+            dispatch_uid='tags_handler_index_document',
+            sender=Tag.documents.through
+        )
+
+        pre_delete.connect(
+            handler_tag_pre_delete,
+            dispatch_uid='tags_handler_tag_pre_delete',
+            sender=Tag
+        )

mayan/apps/tags/handlers.py

@@ -0,0 +1,21 @@
+from __future__ import unicode_literals
+
+import logging
+
+from document_indexing.tasks import task_index_document
+
+logger = logging.getLogger(__name__)
+
+
+def handler_index_document(sender, **kwargs):
+    if kwargs['action'] in ('post_add', 'post_remove'):
+        for pk in kwargs['pk_set']:
+            task_index_document.apply_async(kwargs=dict(document_id=pk))
+
+
+def handler_tag_pre_delete(sender, **kwargs):
+    for document in kwargs['instance'].documents.all():
+        # Remove each of the documents from the tag
+        # Trigger the m2m_changed signal for each document so they can be
+        # reindexed
+        kwargs['instance'].documents.remove(document)

mayan/apps/tags/tests/literals.py

@@ -4,3 +4,20 @@ TEST_TAG_LABEL = 'test-tag'
 TEST_TAG_LABEL_EDITED = 'test-tag-edited'
 TEST_TAG_COLOR = '#001122'
 TEST_TAG_COLOR_EDITED = '#221100'
+
+TEST_TAG_INDEX_HAS_TAG = 'HAS_TAG'
+TEST_TAG_INDEX_NO_TAG = 'NO_TAG'
+TEST_TAG_INDEX_NODE_TEMPLATE = '''
+{{% for tag in document.tags.all %}}
+{{% if tag.label == "{}" %}}
+{}
+{{% else %}}
+NO_TAG
+{{% endif %}}
+{{% empty %}}
+NO_TAG
+{{% endfor %}}
+'''.format(
+    TEST_TAG_LABEL, TEST_TAG_INDEX_HAS_TAG, TEST_TAG_INDEX_NO_TAG,
+    TEST_TAG_INDEX_NO_TAG
+).replace('\n', '')

mayan/apps/tags/tests/test_indexing.py

@@ -0,0 +1,73 @@
+from __future__ import unicode_literals
+
+from django.core.files.base import File
+from django.test import override_settings
+
+from common.tests import BaseTestCase
+from documents.models import DocumentType
+from documents.tests import TEST_DOCUMENT_TYPE_LABEL, TEST_SMALL_DOCUMENT_PATH
+from document_indexing.models import Index, IndexInstanceNode
+from document_indexing.tests.literals import TEST_INDEX_LABEL
+
+from ..models import Tag
+
+from .literals import (
+    TEST_TAG_COLOR, TEST_TAG_LABEL, TEST_TAG_INDEX_HAS_TAG,
+    TEST_TAG_INDEX_NO_TAG, TEST_TAG_INDEX_NODE_TEMPLATE
+)
+
+
+@override_settings(OCR_AUTO_OCR=False)
+class TagSignalIndexingTestCase(BaseTestCase):
+    def setUp(self):
+        super(TagSignalIndexingTestCase, self).setUp()
+        self.document_type = DocumentType.objects.create(
+            label=TEST_DOCUMENT_TYPE_LABEL
+        )
+
+    def tearDown(self):
+        self.document.delete()
+        self.document_type.delete()
+        super(TagSignalIndexingTestCase, self).tearDown()
+
+    def _create_document(self):
+        with open(TEST_SMALL_DOCUMENT_PATH) as file_object:
+            self.document = self.document_type.new_document(
+                file_object=File(file_object)
+            )
+
+    def test_tag_indexing(self):
+        index = Index.objects.create(label=TEST_INDEX_LABEL)
+
+        index.document_types.add(self.document_type)
+
+        root = index.template_root
+        index.node_templates.create(
+            parent=root, expression=TEST_TAG_INDEX_NODE_TEMPLATE,
+            link_documents=True
+        )
+
+        tag = Tag.objects.create(color=TEST_TAG_COLOR, label=TEST_TAG_LABEL)
+        self._create_document()
+
+        self.assertTrue(
+            self.document in IndexInstanceNode.objects.get(
+                value=TEST_TAG_INDEX_NO_TAG
+            ).documents.all()
+        )
+
+        tag.documents.add(self.document)
+
+        self.assertTrue(
+            self.document in IndexInstanceNode.objects.get(
+                value=TEST_TAG_INDEX_HAS_TAG
+            ).documents.all()
+        )
+
+        tag.delete()
+
+        self.assertTrue(
+            self.document in IndexInstanceNode.objects.get(
+                value=TEST_TAG_INDEX_NO_TAG
+            ).documents.all()
+        )