feat: Adds the HORIZONTAL_FILTER_BAR feature flag (#21935)

RESOURCES/FEATURE_FLAGS.md

@@ -35,6 +35,7 @@ These features are considered **unfinished** and should only be used on developm
 - ENABLE_ADVANCED_DATA_TYPES
 - ENABLE_EXPLORE_JSON_CSRF_PROTECTION
 - ENABLE_TEMPLATE_REMOVE_FILTERS
+- HORIZONTAL_FILTER_BAR
 - KV_STORE
 - PRESTO_EXPAND_DATA
 - REMOVE_SLICE_LEVEL_LABEL_COLORS

superset-frontend/packages/superset-ui-core/src/utils/featureFlags.ts

@@ -52,6 +52,7 @@ export enum FeatureFlag {
   FORCE_DATABASE_CONNECTIONS_SSL = 'FORCE_DATABASE_CONNECTIONS_SSL',
   GENERIC_CHART_AXES = 'GENERIC_CHART_AXES',
   GLOBAL_ASYNC_QUERIES = 'GLOBAL_ASYNC_QUERIES',
+  HORIZONTAL_FILTER_BAR = 'HORIZONTAL_FILTER_BAR',
   LISTVIEWS_DEFAULT_CARD_VIEW = 'LISTVIEWS_DEFAULT_CARD_VIEW',
   SCHEDULED_QUERIES = 'SCHEDULED_QUERIES',
   SHARE_QUERIES_VIA_KV_STORE = 'SHARE_QUERIES_VIA_KV_STORE',

superset/config.py

@@ -469,6 +469,7 @@ DEFAULT_FEATURE_FLAGS: Dict[str, bool] = {
     "EMBEDDABLE_CHARTS": True,
     "DRILL_TO_DETAIL": False,
     "DATAPANEL_CLOSED_BY_DEFAULT": False,
+    "HORIZONTAL_FILTER_BAR": False,
 }
 
 # Feature flags may also be set via 'SUPERSET_FEATURE_' prefixed environment vars.