Event handlers and Flex changes

src/Gridler/components/Column.tsx

@@ -18,7 +18,7 @@ export interface GridlerColumn extends Partial<BaseGridColumn> {
     colIndx: string,
     value: any,
     storeState: GridlerStoreState
-  ) => GridCellLoose;
+  ) => Partial<GridCellLoose>;
   defaultIcon?: string;
   disableFilter?: boolean;
   disableMove?: boolean;