From 0d1a31fc8234ce79075c0d6811269d5fa37a95da Mon Sep 17 00:00:00 2001
From: Brian White <mscdex@mscdex.net>
Date: Tue, 26 Mar 2024 21:54:26 -0400
Subject: [PATCH] New: Allow fixed header for Excel spreadsheets

---
 docs/button/excelHtml5.xml |  4 ++++
 js/buttons.html5.js        | 26 ++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/docs/button/excelHtml5.xml b/docs/button/excelHtml5.xml
index d4b9385e..d4edffff 100644
--- a/docs/button/excelHtml5.xml
+++ b/docs/button/excelHtml5.xml
@@ -225,6 +225,10 @@
 		Enable Excel's auto filter feature for the header cells in the table allowing the user to quickly filter and sort the exported spreadsheet in Excel. Note that this does not operate in LibreOffice (although the spreadsheet is still readable).
 	</option>
 
+	<option type="boolean" name="fixedHeader" default="false" since="3.0.2">
+		Freeze the header cells in the table allowing the user to always see the header as they scroll the spreadsheet.
+	</option>
+
 
 
 	<example title="DataTables initialisation: Use the HTML5 Excel button"><![CDATA[
diff --git a/js/buttons.html5.js b/js/buttons.html5.js
index 26bacdf2..b952d421 100644
--- a/js/buttons.html5.js
+++ b/js/buttons.html5.js
@@ -1317,6 +1317,32 @@ DataTable.ext.buttons.excelHtml5 = {
 			);
 		}
 
+		// Make the header fixed while scrolling
+		if (config.fixedHeader) {
+			var sheetViews = _createNode(rels, 'sheetViews', {
+				children: [
+					_createNode(rels, 'sheetView', {
+						attr: {
+							tabSelected: '1',
+							workbookViewId: '0'
+						},
+						children: [
+							_createNode(rels, 'pane', {
+								attr: {
+									xSplit: '0',
+									ySplit: '2',
+									topLeftCell: 'A' + (dataStartRow + 1),
+									activePane: 'bottomRight',
+									state: 'frozen'
+								}
+							})
+						]
+					})
+				]
+			});
+			$('worksheet', rels).prepend(sheetViews);
+		}
+
 		// Workbook modifications
 		var workbook = xlsx.xl['workbook.xml'];