Add support for natural keys to the DocumentPageImageCache model.

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

HISTORY.rst

@@ -8,6 +8,7 @@
 * Add test mixin to test the db conversion (dumping and loading) of a specific app.
 * Add an user test mixin to group user testing.
 * Add test the user managament app for database conversion.
+* Add support for natural keys to the DocumentPageImageCache model.
 
 3.1.1 (2018-09-18)
 ==================

mayan/apps/documents/managers.py

@@ -34,6 +34,21 @@ class DocumentManager(models.Manager):
             document.invalidate_cache()
 
 
+class DocumentPageCachedImage(models.Manager):
+    def get_by_natural_key(self, filename, document_page_natural_key):
+        DocumentPage = apps.get_model(
+            app_label='documents', model_name='DocumentPage'
+        )
+        try:
+            document_page = DocumentPage.objects.get_by_natural_key(
+                *document_page_natural_key
+            )
+        except DocumentPage.DoesNotExist:
+            raise self.model.DoesNotExist
+
+        return self.get(document_page__pk=document_page.pk, filename=filename)
+
+
 class DocumentPageManager(models.Manager):
     def get_by_natural_key(self, page_number, document_version_natural_key):
         DocumentVersion = apps.get_model(

mayan/apps/documents/models.py

@@ -36,9 +36,10 @@ from .events import (
 )
 from .literals import DEFAULT_DELETE_PERIOD, DEFAULT_DELETE_TIME_UNIT
 from .managers import (
-    DocumentManager, DocumentPageManager, DocumentVersionManager,
+    DocumentManager, DocumentPageCachedImage, DocumentPageManager,
-    DocumentTypeManager, DuplicatedDocumentManager, FavoriteDocumentManager,
+    DocumentVersionManager, DocumentTypeManager, DuplicatedDocumentManager,
-    PassthroughManager, RecentDocumentManager, TrashCanManager
+    FavoriteDocumentManager, PassthroughManager, RecentDocumentManager,
+    TrashCanManager
 )
 from .permissions import permission_document_view
 from .settings import (
@@ -1005,6 +1006,8 @@ class DocumentPageCachedImage(models.Model):
         db_index=True, default=0, verbose_name=_('File size')
     )
 
+    objects = DocumentPageCachedImage()
+
     class Meta:
         verbose_name = _('Document page cached image')
         verbose_name_plural = _('Document page cached images')
@@ -1013,6 +1016,10 @@ class DocumentPageCachedImage(models.Model):
         storage_documentimagecache.delete(self.filename)
         return super(DocumentPageCachedImage, self).delete(*args, **kwargs)
 
+    def natural_key(self):
+        return (self.filename, self.document_page.natural_key())
+    natural_key.dependencies = ['documents.DocumentPage']
+
     def save(self, *args, **kwargs):
         self.file_size = storage_documentimagecache.size(self.filename)
         return super(DocumentPageCachedImage, self).save(*args, **kwargs)

mayan/apps/documents/tests/test_models.py

@@ -18,13 +18,18 @@ from .literals import (
     TEST_PDF_INDIRECT_ROTATE_PATH, TEST_OFFICE_DOCUMENT_PATH,
     TEST_SMALL_DOCUMENT_CHECKSUM, TEST_SMALL_DOCUMENT_FILENAME,
     TEST_SMALL_DOCUMENT_MIMETYPE, TEST_SMALL_DOCUMENT_PATH,
-    TEST_SMALL_DOCUMENT_SIZE
+    TEST_SMALL_DOCUMENT_SIZE, TEST_DOCUMENT_FILENAME
 )
 from .mixins import DocumentTestMixin
 
 
 @override_settings(OCR_AUTO_OCR=False)
 class DocumentTestCase(DocumentTestMixin, BaseTestCase):
+    def test_natural_keys(self):
+        self.document.pages.first().generate_image()
+
+        self._test_database_conversion('documents')
+
     def test_document_creation(self):
         self.assertEqual(self.document_type.label, TEST_DOCUMENT_TYPE_LABEL)