New Config Variable: INDEXER_BEFORE_INDEX_HOOKS

In the init_app, connects functions provided in the INDEXER_BEFORE_INDEX_HOOKS config variable to the before_record_index signal.

invenio_indexer/ext.py

@@ -26,11 +26,13 @@
 
 from __future__ import absolute_import, print_function
 
+import six
 from flask import current_app
 from werkzeug.utils import cached_property, import_string
 
 from . import config
 from .cli import run  # noqa
+from .signals import before_record_index
 
 
 class InvenioIndexer(object):
@@ -52,6 +54,15 @@ def init_app(self, app):
         self.init_config(app)
         app.extensions['invenio-indexer'] = self
 
+        hooks = app.config.get('INDEXER_BEFORE_INDEX_HOOKS', [])
+        for hook in hooks:
+            if callable(hook):
+                before_record_index.connect_via(app)(hook)
+            elif isinstance(hook, six.string_types):
+                before_record_index.connect_via(app)(import_string(hook))
+            elif hook:
+                before_record_index.connect_via(app)(hook)
+
     def init_config(self, app):
         """Initialize configuration.