fix: allow exporting large reports that can't be rendered (backport #…

…25395) (#25404)

* fix: dont render very large reports, offer export instead

(cherry picked from commit 65fb8dc)

# Conflicts:
#	frappe/public/js/frappe/views/reports/query_report.js

* chore: conflicts

* fix: make excel export work without rendering

* fix: hide CSV option if not available

---------

Co-authored-by: Ankush Menat <ankush@frappe.io>

frappe/desk/query_report.py

@@ -385,7 +385,7 @@ def build_xlsx_data(data, visible_idx, include_indentation, ignore_visible_idx=F
 		datetime.timedelta,
 	)
 
-	if len(visible_idx) == len(data.result):
+	if len(visible_idx) == len(data.result) or not visible_idx:
 		# It's not possible to have same length and different content.
 		ignore_visible_idx = True
 	else:

frappe/public/js/frappe/views/reports/query_report.js

@@ -745,15 +745,19 @@ frappe.views.QueryReport = class QueryReport extends frappe.views.BaseList {
 
 	add_prepared_report_buttons(doc) {
 		if (doc) {
-			this.page.add_inner_button(__("Download Report"), function () {
-				window.open(
-					frappe.urllib.get_full_url(
-						"/api/method/frappe.core.doctype.prepared_report.prepared_report.download_attachment?" +
-							"dn=" +
-							encodeURIComponent(doc.name)
-					)
-				);
-			});
+			this.page.add_inner_button(
+				__("Download Report"),
+				function () {
+					window.open(
+						frappe.urllib.get_full_url(
+							"/api/method/frappe.core.doctype.prepared_report.prepared_report.download_attachment?" +
+								"dn=" +
+								encodeURIComponent(doc.name)
+						)
+					);
+				},
+				__("Actions")
+			);
 
 			let pretty_diff = frappe.datetime.comment_when(doc.report_end_time);
 			const days_old = frappe.datetime.get_day_diff(
@@ -937,6 +941,16 @@ frappe.views.QueryReport = class QueryReport extends frappe.views.BaseList {
 		let data = this.data;
 		let columns = this.columns.filter((col) => !col.hidden);
 
+		if (data.length > 100000) {
+			let msg = __(
+				"This report contains {0} rows and is too big to display in browser, you can {1} this report instead.",
+				[cstr(format_number(data.length, null, 0)).bold(), __("export").bold()]
+			);
+
+			this.toggle_message(true, `${frappe.utils.icon("solid-warning")} ${msg}`);
+			return;
+		}
+
 		if (this.raw_data.add_total_row && !this.report_settings.tree) {
 			data = data.slice();
 			data.splice(-1, 1);
@@ -1453,12 +1467,17 @@ frappe.views.QueryReport = class QueryReport extends frappe.views.BaseList {
 			return;
 		}
 
+		let export_options = ["Excel"];
+		if (this.datatable) {
+			export_options.push("CSV");
+		}
+
 		let export_dialog_fields = [
 			{
 				label: __("Select File Format"),
 				fieldname: "file_format",
 				fieldtype: "Select",
-				options: ["Excel", "CSV"],
+				options: export_options,
 				default: "Excel",
 				reqd: 1,
 			},
@@ -1496,15 +1515,15 @@ frappe.views.QueryReport = class QueryReport extends frappe.views.BaseList {
 						);
 					}
 
-					const visible_idx = this.datatable.bodyRenderer.visibleRowIndices;
-					if (visible_idx.length + 1 === this.data.length) {
+					const visible_idx = this.datatable?.bodyRenderer.visibleRowIndices || [];
+					if (visible_idx.length + 1 === this.data?.length) {
 						visible_idx.push(visible_idx.length);
 					}
 
 					const args = {
 						cmd: "frappe.desk.query_report.export_query",
 						report_name: this.report_name,
-						custom_columns: this.custom_columns.length ? this.custom_columns : [],
+						custom_columns: this.custom_columns?.length ? this.custom_columns : [],
 						file_format_type: file_format,
 						filters: filters,
 						visible_idx,