Citadel: Use new search backend active check

And more important, do not access the DB during app initialization

citadel/indico_citadel/plugin.py

@@ -5,7 +5,6 @@
 # them and/or modify them under the terms of the MIT License;
 # see the LICENSE file for more details.
 
-from flask import current_app
 from wtforms.fields.core import BooleanField
 from wtforms.fields.html5 import IntegerField, URLField
 from wtforms.validators import URL, DataRequired, NumberRange
@@ -85,13 +84,9 @@ class CitadelPlugin(LiveSyncPluginBase):
         self.connect(signals.get_search_providers, self.get_search_providers)
         self.connect(signals.plugin.cli, self._extend_indico_cli)
 
-    def _is_configured(self):
-        return bool(self.settings.get('search_backend_url')) and bool(self.settings.get('search_backend_token'))
-
     def get_search_providers(self, sender, **kwargs):
         from indico_citadel.search import CitadelProvider
-        if current_app.config['TESTING'] or (not self.settings.get('disable_search') and self._is_configured()):
-            return CitadelProvider
+        return CitadelProvider
 
     def _extend_indico_cli(self, sender, **kwargs):
         return cli

citadel/indico_citadel/search.py

@@ -9,10 +9,12 @@ import base64
 import zlib
 
 import requests
+from flask import current_app
 from requests.exceptions import RequestException
 from werkzeug.urls import url_join
 
 from indico.modules.search.base import IndicoSearchProvider, SearchOption
+from indico.util.decorators import classproperty
 
 from indico_citadel import _
 from indico_citadel.result_schemas import CitadelResultSchema
@@ -28,6 +30,17 @@ class CitadelProvider(IndicoSearchProvider):
         self.backend_url = CitadelPlugin.settings.get('search_backend_url')
         self.records_url = url_join(self.backend_url, 'api/records/')
 
+    @classproperty
+    @classmethod
+    def active(cls):
+        from indico_citadel.plugin import CitadelPlugin
+        if current_app.config['TESTING']:
+            return True
+        elif CitadelPlugin.settings.get('disable_search'):
+            return False
+        return bool(CitadelPlugin.settings.get('search_backend_url') and
+                    CitadelPlugin.settings.get('search_backend_token'))
+
     def search(self, query, user=None, page=1, object_types=(), **params):
         # https://cern-search.docs.cern.ch/usage/operations/#query-documents
         # this token is used by the backend to authenticate and also to filter