GeoNode#10995 Faceting: lazy initialization

geonode/facets/apps.py

@@ -25,8 +25,6 @@
 
 logger = logging.getLogger(__name__)
 
-registered_facets = dict()
-
 
 class GeoNodeFacetsConfig(AppConfig):
     name = "geonode.facets"
@@ -38,21 +36,44 @@ def ready(self):
 
         urlpatterns += urls.urlpatterns
 
-        init_providers()
 
+class FacetsRegistry:
+    def __init__(self):
+        self.facet_providers = None
+
+    def _load_facets_configuration(self) -> None:
+        """
+        Facet loading is done lazily because some FacetProvider may need to access the DB, which may not have been
+        initialized/created yet
+        """
+        self.facet_providers = dict()
+
+        from geonode.facets.providers.thesaurus import create_thesaurus_providers
+        from geonode.facets.providers.users import OwnerFacetProvider
+
+        logger.info(f"Initializing Facets")
+
+        self.register_facet_provider(CategoryFacetProvider())
+        self.register_facet_provider(OwnerFacetProvider())
+
+        # Thesaurus providers initialization should be called at startup and
+        # whenever records in Thesaurus or ThesaurusLabel change
+        for provider in create_thesaurus_providers():
+            self.register_facet_provider(provider)
 
-def init_providers():
-    from geonode.facets.providers.thesaurus import create_thesaurus_providers
-    from geonode.facets.providers.users import OwnerFacetProvider
+    def register_facet_provider(self, provider: FacetProvider):
+        logger.info(f"Registering {provider}")
+        self.facet_providers[provider.get_info()["name"]] = provider
 
-    register_facet_provider(CategoryFacetProvider())
-    register_facet_provider(OwnerFacetProvider())
+    def get_providers(self):
+        if self.facet_providers is None:
+            self._load_facets_configuration()
+        return self.facet_providers.values()
 
-    # Thesaurus providers initialiazion should be called at startup and whenever records in Thesaurus or ThesaurusLabel change
-    for provider in create_thesaurus_providers():
-        register_facet_provider(provider)
+    def get_provider(self, name):
+        if self.facet_providers is None:
+            self._load_facets_configuration()
+        return self.facet_providers.get(name, None)
 
 
-def register_facet_provider(provider: FacetProvider):
-    logging.info(f"Registering {provider}")
-    registered_facets[provider.get_info()["name"]] = provider
+facet_registry = FacetsRegistry()

geonode/facets/views.py

@@ -8,7 +8,7 @@
 from django.urls import reverse
 
 from geonode.base.models import ResourceBase
-from geonode.facets.apps import registered_facets
+from geonode.facets.apps import facet_registry
 from geonode.facets.models import FacetProvider, DEFAULT_FACET_PAGE_SIZE
 from geonode.security.utils import get_visible_resources
 
@@ -31,7 +31,7 @@ def list_facets(request, **kwargs):
 
     facets = []
 
-    for provider in registered_facets.values():
+    for provider in facet_registry.get_providers():
         logger.debug("Fetching data from provider %r", provider)
         info = provider.get_info(lang=lang)
         if add_links:
@@ -55,7 +55,7 @@ def get_facet(request, facet):
     logger.debug("get_facet -> %r for user '%r'", facet, request.user.username)
 
     # retrieve provider for the requested facet
-    provider: FacetProvider = registered_facets.get(facet)
+    provider: FacetProvider = facet_registry.get_provider(facet)
     if not provider:
         return HttpResponseNotFound()