Add OCR content deleted event

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

mayan/apps/ocr/apps.py

@@ -14,9 +14,14 @@ from mayan.apps.common.menus import (
 )
 from mayan.apps.documents.search import document_search, document_page_search
 from mayan.apps.documents.signals import post_version_upload
+from mayan.apps.events.classes import ModelEventType
 from mayan.apps.navigation.classes import SourceColumn
 
 from .dependencies import *  # NOQA
+from .events import (
+    event_ocr_document_content_deleted, event_ocr_document_version_finish,
+    event_ocr_document_version_submit
+)
 from .handlers import (
     handler_index_document, handler_initialize_new_ocr_settings,
     handler_ocr_document_version,
@@ -83,6 +88,14 @@ class OCRApp(MayanAppConfig):
             name='submit_for_ocr', value=method_document_version_ocr_submit
         )
 
+        ModelEventType.register(
+            model=Document, event_types=(
+                event_ocr_document_content_deleted,
+                event_ocr_document_version_finish,
+                event_ocr_document_version_submit
+            )
+        )
+
         ModelField(
             model=Document, name='versions__pages__ocr_content__content'
         )