Column Customization: Add feature flag

Author: JamesHollyer

tensorboard/webapp/feature_flag/store/feature_flag_metadata.ts

@@ -121,6 +121,11 @@ export const FeatureFlagMetadataMap: FeatureFlagMetadataMapType<FeatureFlags> =
       queryParamOverride: 'enableProspectiveFob',
       parseValue: parseBoolean,
     },
+    enableScalarColumnCustomization: {
+      defaultValue: false,
+      queryParamOverride: 'enableScalarColumnCustomization',
+      parseValue: parseBoolean,
+    },
   };
 
 /**

tensorboard/webapp/feature_flag/store/feature_flag_selectors.ts

@@ -170,3 +170,10 @@ export const getIsLinkedTimeProspectiveFobEnabled = createSelector(
     return flags.enabledProspectiveFob;
   }
 );
+
+export const getIsScalarColumnCustomizationEnabled = createSelector(
+  getFeatureFlags,
+  (flags: FeatureFlags): boolean => {
+    return flags.enableScalarColumnCustomization;
+  }
+);

tensorboard/webapp/feature_flag/types.ts

@@ -51,4 +51,7 @@ export interface FeatureFlags {
   // In Linked Time, if enabled, show a prospective fob user to turn on the feature or select a step.
   // If this is removed update the `getCurrentFob` method of tensorboard/webapp/widgets/card_fob/card_fob_controller_component.ts
   enabledProspectiveFob: boolean;
+  // Adds affordance for users to select and reorder the columns in the Scalar
+  // Card Data Table
+  enableScalarColumnCustomization: boolean;
 }