From 5dabf6681c3a0b59ed04926cd5d13ad20feba298 Mon Sep 17 00:00:00 2001
From: mmd-osm <mmd.osm@gmail.com>
Date: Sat, 26 Jul 2025 13:33:17 +0200
Subject: [PATCH] Map XML download with Turbo

---
 app/assets/javascripts/index/export.js | 50 ++++++++++++++++++++++++++
 app/views/site/export.html.erb         |  4 +--
 config/locales/en.yml                  |  1 +
 3 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/app/assets/javascripts/index/export.js b/app/assets/javascripts/index/export.js
index 05d90381b..8fd361bb3 100644
--- a/app/assets/javascripts/index/export.js
+++ b/app/assets/javascripts/index/export.js
@@ -70,6 +70,56 @@ OSM.Export = function (map) {
     $("#drag_box").click(enableFilter);
     $(".export_form").on("submit", checkSubmit);
 
+    function downloadBlob(blob, filename) {
+      const url = URL.createObjectURL(blob);
+      const a = document.createElement("a");
+      a.href = url;
+      a.download = filename;
+      document.body.appendChild(a);
+      a.click();
+      document.body.removeChild(a);
+      URL.revokeObjectURL(url);
+    }
+
+    async function handleExportSuccess(fetchResponse) {
+      try {
+        const blob = await fetchResponse.response.blob();
+        downloadBlob(blob, "map.osm");
+      } catch (err) {
+        // eslint-disable-next-line no-alert
+        alert(OSM.i18n.t("javascripts.share.export_failed", { reason: "(blob error)" }));
+      }
+    }
+
+    async function handleExportError(event) {
+      let detailMessage;
+      try {
+        detailMessage = event?.detail?.error?.message;
+        if (!detailMessage) {
+          const responseText = await event.detail.fetchResponse.responseText;
+          const parser = new DOMParser();
+          const doc = parser.parseFromString(responseText, "text/html");
+          detailMessage = doc.body ? doc.body.textContent.trim() : "(unknown)";
+        }
+      } catch (err) {
+        detailMessage = "(unknown)";
+      }
+      // eslint-disable-next-line no-alert
+      alert(OSM.i18n.t("javascripts.share.export_failed", { reason: detailMessage }));
+    }
+
+    document.querySelector(".export_form").addEventListener("turbo:submit-end", function (event) {
+      if (event.detail.success) {
+        handleExportSuccess(event.detail.fetchResponse);
+      } else {
+        handleExportError(event);
+      }
+    });
+
+    document.querySelector(".export_form").addEventListener("turbo:before-fetch-request", function (event) {
+      event.detail.fetchOptions.headers.Accept = "application/xml";
+    });
+
     update();
     return map.getState();
   };
diff --git a/app/views/site/export.html.erb b/app/views/site/export.html.erb
index 248fea8cd..5978f992a 100644
--- a/app/views/site/export.html.erb
+++ b/app/views/site/export.html.erb
@@ -2,7 +2,7 @@
 
 <%= render "sidebar_header", :title => t(".title") %>
 
-<%= form_tag({ :controller => "export", :action => "finish" }, { :class => "export_form" }) do %>
+<%= form_tag({ :controller => "export", :action => "finish" }, :class => "export_form", :data => { "turbo" => true }) do %>
   <%= hidden_field_tag "format", "osm", :autocomplete => "off" %>
 
   <div class='export_area_inputs text-center mb-3'>
@@ -28,7 +28,7 @@
 
   <div id="export_commit">
     <div class="mb-3 d-flex">
-      <%= submit_tag t(".export_button"), :class => "btn btn-primary mx-auto" %>
+      <%= submit_tag t(".export_button"), :class => "btn btn-primary mx-auto", :data => { "turbo-submits-with" => t(".export_download") } %>
     </div>
   </div>
 
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 0fb9f9e18..ac3ff3932 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -2498,6 +2498,7 @@ en:
           title: "Other Sources"
           description: "Additional sources listed on the OpenStreetMap Wiki"
       export_button: "Export"
+      export_download: "Downloading..."
     fixthemap:
       title: Report a problem / Fix the map
       how_to_help:
-- 
2.39.5