From dcda5a52cea63d3823370df377f820d9890526a7 Mon Sep 17 00:00:00 2001
From: MarekSpodBiedry <73122968+MarekSpodBiedry@users.noreply.github.com>
Date: Sat, 10 Oct 2026 19:04:04 +0200
Subject: [PATCH] Deliver Export as PDF as a browser download (#141)

---
 crates/ui-egui/src/lib.rs         | 18 ++++++++++++++++++
 crates/ui-egui/tests/file_menu.rs | 15 +++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/crates/ui-egui/src/lib.rs b/crates/ui-egui/src/lib.rs
index c3efe3b..457b326 100644
--- a/crates/ui-egui/src/lib.rs
+++ b/crates/ui-egui/src/lib.rs
@@ -214,6 +214,11 @@ impl SheetApp {
         }
         let r = self.session.run(id, params);
         self.after_engine();
+        if id == "file.exportPdf"
+            && let Ok(r) = &r
+        {
+            self.deliver_pdf(r);
+        }
         r
     }
 
@@ -234,6 +239,19 @@ impl SheetApp {
         ctx.copy_text(text.to_string());
     }
 
+    /// Web: `file.exportPdf` without a path returns the PDF as base64; hand it to the browser as a download.
+    fn deliver_pdf(&self, result: &Json) {
+        if result.get("path").is_some() {
+            return;
+        }
+        if let Some(dl) = &self.services.download
+            && let Some(b) = result.get("base64").and_then(Json::as_str).and_then(gridcraft_engine::io::base64_decode)
+        {
+            let title = self.session.active().map(|d| d.display_title()).unwrap_or_else(|| "Book1".into());
+            dl(&std::path::Path::new(&title).with_extension("pdf").to_string_lossy(), &b);
+        }
+    }
+
     /// Runs a command and shows its error in a message box (for menu/ribbon clicks).
     pub fn run_or_alert(&mut self, id: &str, params: Json) {
         if let Err(e) = self.run(id, params) {
diff --git a/crates/ui-egui/tests/file_menu.rs b/crates/ui-egui/tests/file_menu.rs
index 5f6ca7c..f3b07f4 100644
--- a/crates/ui-egui/tests/file_menu.rs
+++ b/crates/ui-egui/tests/file_menu.rs
@@ -74,3 +74,18 @@ fn save_actions_include_the_cell_draft_and_close_keeps_the_unsaved_prompt() {
     assert_eq!(h.state().dialog.as_ref().map(|d| d.name()), Some("saveChanges"));
     assert_eq!(h.state().session.active().unwrap().wb.active().unwrap().value(CellRef::new(0, 0)), Value::Number(123.0));
 }
+
+#[test]
+fn export_as_pdf_is_delivered_as_a_download() {
+    let files = Arc::new(Mutex::new(Vec::<(String, Vec<u8>)>::new()));
+    let capture = files.clone();
+    let mut h = harness(Services {
+        download: Some(Box::new(move |name, bytes| capture.lock().unwrap().push((name.to_string(), bytes.to_vec())))),
+        ..Default::default()
+    });
+    h.state_mut().run("file.exportPdf", serde_json::json!({})).unwrap();
+    let got = files.lock().unwrap();
+    assert_eq!(got.len(), 1, "Export as PDF hands a file to the browser");
+    assert!(got[0].0.ends_with(".pdf"));
+    assert!(got[0].1.starts_with(b"%PDF-"));
+}