Refactor the model accesors

Refactor the accesors to behave like methods instead of properties.
This means all accesors will be prepended with the string
"get_" and will include a set of parenthesis.

Improve the ModeAttribute class to use the method's
short_description. This commit also adds support for a
new method .help_text attribute has been added.

Move accessors to their own module, named "methods.py".

Remove the PropertyHelper class as the accessors no longer
need it.

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

mayan/apps/ocr/methods.py

@@ -0,0 +1,51 @@
+from __future__ import unicode_literals
+
+from datetime import timedelta
+
+from django.utils.timezone import now
+from django.utils.translation import ugettext_lazy as _
+
+from mayan.apps.common.settings import settings_db_sync_task_delay
+
+from .events import event_ocr_document_version_submit
+from .tasks import task_do_ocr
+from .utils import get_document_version_content_iterator
+
+
+def method_document_ocr_submit(self):
+    latest_version = self.latest_version
+    # Don't error out if document has no version
+    if latest_version:
+        latest_version.submit_for_ocr()
+
+
+def method_document_version_ocr_submit(self):
+    event_ocr_document_version_submit.commit(
+        action_object=self.document, target=self
+    )
+
+    task_do_ocr.apply_async(
+        eta=now() + timedelta(seconds=settings_db_sync_task_delay.value),
+        kwargs={'document_version_pk': self.pk},
+    )
+
+
+def method_get_document_ocr_content(self):
+    latest_version = self.latest_version
+    # Don't error out if document has no version
+    if latest_version:
+        latest_version.get_ocr_content()
+
+
+method_get_document_ocr_content.short_description = _(
+    'get_ocr_content()'
+)
+method_get_document_ocr_content.help_text = _(
+    'Return the OCR content of the document.'
+)
+
+
+def method_get_document_version_ocr_content(self):
+    return ' '.join(
+        get_document_version_content_iterator(document_version=self)
+    )