Removed log components and introduced signals for tags & correspondents

src/documents/signals/__init__.py

@@ -0,0 +1,4 @@
+from django.dispatch import Signal
+
+document_consumption_started = Signal(providing_args=["filename"])
+document_consumption_finished = Signal(providing_args=["document"])

src/documents/signals/handlers.py

@@ -0,0 +1,53 @@
+import logging
+
+from ..models import Correspondent, Tag
+
+
+def logger(message, group):
+    logging.getLogger(__name__).debug(message, extra={"group": group})
+
+
+def set_correspondent(sender, document=None, logging_group=None, **kwargs):
+
+    # No sense in assigning a correspondent when one is already set.
+    if document.correspondent:
+        return
+
+    # No matching correspondents, so no need to continue
+    potential_correspondents = Correspondent.match_all(document.content)
+    if not potential_correspondents:
+        return
+
+    potential_count = len(potential_correspondents)
+    selected = potential_correspondents[0]
+    if potential_count > 1:
+        message = "Detected {} potential correspondents, so we've opted for {}"
+        logger(
+            message.format(potential_count, selected),
+            logging_group
+        )
+
+    logger(
+        'Assigning correspondent "{}" to "{}" '.format(selected, document),
+        logging_group
+    )
+
+    document.correspondent = selected
+    document.save(update_fields="correspondent")
+
+
+def set_tags(sender, document=None, logging_group=None, **kwargs):
+
+    current_tags = set(document.tags.all())
+    relevant_tags = set(Tag.match_all(document.content)) - current_tags
+
+    if not relevant_tags:
+        return
+
+    message = 'Tagging "{}" with "{}"'
+    logger(
+        message.format(document, ", ".join([t.slug for t in relevant_tags])),
+        logging_group
+    )
+
+    document.tags.add(*relevant_tags)