[DataGrid] Fix ugly prop-types for the pageStyle prop of the `GridP…

…rintExportMenuItem` component (#15015)

docs/pages/x/api/data-grid/grid-print-export-options.json

@@ -18,6 +18,6 @@
     "hideFooter": { "type": { "description": "boolean" }, "default": "false" },
     "hideToolbar": { "type": { "description": "boolean" }, "default": "false" },
     "includeCheckboxes": { "type": { "description": "boolean" }, "default": "false" },
-    "pageStyle": { "type": { "description": "string | Function" } }
+    "pageStyle": { "type": { "description": "string | (() => string)" } }
   }
 }

packages/x-data-grid/src/components/toolbar/GridToolbarExport.tsx

@@ -107,22 +107,7 @@ GridPrintExportMenuItem.propTypes = {
     hideFooter: PropTypes.bool,
     hideToolbar: PropTypes.bool,
     includeCheckboxes: PropTypes.bool,
-    pageStyle: PropTypes.oneOfType([
-      PropTypes.shape({
-        '__@hasInstance@646': PropTypes.func.isRequired,
-        '__@metadata@648': PropTypes.any,
-        apply: PropTypes.func.isRequired,
-        arguments: PropTypes.any.isRequired,
-        bind: PropTypes.func.isRequired,
-        call: PropTypes.func.isRequired,
-        caller: PropTypes.object.isRequired,
-        length: PropTypes.number.isRequired,
-        name: PropTypes.string.isRequired,
-        prototype: PropTypes.any.isRequired,
-        toString: PropTypes.func.isRequired,
-      }),
-      PropTypes.string,
-    ]),
+    pageStyle: PropTypes.oneOfType([PropTypes.func, PropTypes.string]),
   }),
 } as any;
 

packages/x-data-grid/src/models/gridExport.ts

@@ -149,7 +149,7 @@ export interface GridPrintExportOptions extends GridExportOptions {
   /**
    * Provide Print specific styles to the print window.
    */
-  pageStyle?: string | Function;
+  pageStyle?: string | (() => string);
   /**
    * Function that returns the list of row ids to export in the order they should be exported.
    * @param {GridPrintGetRowsToExportParams} params With all properties from [[GridPrintGetRowsToExportParams]].