Export service and utility function (#2246)

* Changes v1

* Update changelog

Author: jogaj

docs/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## HEAD (unreleased)
 
+- Enhancement: Exporting isNullOrUndefined function and ColumnChangesService service to be used externally.
+
 ## 22.0.0-alpha.0
 
 - Enhancement: Added support for Angular 20

projects/swimlane/ngx-datatable/src/lib/utils/column-helper.ts

@@ -44,3 +44,7 @@ export function toInternalColumn<T extends Row>(
     } as TableColumnInternal; // TS cannot cast here
   });
 }
+
+export function isNullOrUndefined<T>(value: T | null | undefined): value is null | undefined {
+  return value === null || value === undefined;
+}

projects/swimlane/ngx-datatable/src/public-api.ts

@@ -25,6 +25,12 @@ export * from './lib/directives/disable-row.directive';
 export * from './lib/types/public.types';
 export * from './lib/types/table-column.type';
 
+// services
+export * from './lib/services/column-changes.service';
+
+// utilis
+export * from './lib/utils/column-helper';
+
 export {
   providedNgxDatatableConfig,
   NgxDatatableConfig,