added method "customizeZip" to let the developer customise the final zip (XLSX) file content if they want to before it is generated and sent to the browser

Author: alesak

js/buttons.html5.js

@@ -1385,6 +1385,12 @@ DataTable.ext.buttons.excelHtml5 = {
 			filename = filename.substr(0, 175);
 		}
 
+		// Let the developer customize the final zip file if they want to before it is generated and sent to the browser
+		if (config.customizeZip) {
+			config.customizeZip(zip, data, filename);
+		}
+
+
 		if (zip.generateAsync) {
 			// JSZip 3+
 			zip.generateAsync(zipConfig).then(function (blob) {

js/dataTables.buttons.js

@@ -2564,7 +2564,8 @@ var _exportData = function (dt, inOpts) {
 					return Buttons.stripData(d, config);
 				}
 			},
-			customizeData: null
+			customizeData: null,
+			customizeZip: null
 		},
 		inOpts
 	);

types/types.d.ts

@@ -555,6 +555,11 @@ declare module 'datatables.net' {
 		 */
 		customizeData?: FunctionButtonCustomizeData;
 
+		/**
+		 * EXCEL
+		 */
+		customizeZip?: FunctionButtonCustomizeZip;
+
 		/**
 		 * PDF: portrait / landscape
 		 */
@@ -629,4 +634,6 @@ declare module 'datatables.net' {
 	type FunctionButtonCustomizeData = (content: any) => void;
 
 	type FunctionButtonColvisColumnText = (dt: Api<any>, i: number, title: string) => string;
+
+	type FunctionButtonCustomizeZip = (zip: any, data: ButtonsApiExportDataReturn, filename: string) => void;
 }