Let a cached file's GeoJSON be downloaded by clicking its tree name

Once a .gpx/.fit is cached, the tree shows it under its converted name
("ride.gpx" -> "ride.gpx.geojson", matching the real cache file next
to it on disk) instead of still reading as un-converted -- the
GeoJSON is what's actually on the map from that point on, and the
original is never deleted, just not re-shown as itself. The name is
now a real link (GET /api/gpx/file/<path>?download=1) instead of
plain text, the only way to get that converted form out of the app.

Verified in a real browser that an <a> nested in a <label> claims its
own click rather than the label forwarding it to the checkbox, so
downloading and toggling visibility don't fight over the same click.

app.rb

@@ -191,6 +191,10 @@ module Maptool
       json paths: paths, tree: GPX_STORE.tree
     end
 
+    # ?download=1 exports the file's GeoJSON as an attachment instead of
+    # rendering it on the map — the only way to get a .gpx/.fit's converted
+    # form out of the app, since GpxStore#geojson's cache is otherwise an
+    # internal implementation detail with no filename of its own to expose.
     get "/api/gpx/file/*" do
       begin
         body = GPX_STORE.geojson(params[:splat].first)
@@ -203,6 +207,15 @@ module Maptool
       end
 
       content_type :json
+      if params[:download]
+        # Matches the tree's own display name for a cached .gpx/.fit
+        # (public/js/gpx.js's _renderFile) — "ride.gpx" downloads as
+        # "ride.gpx.geojson", not "ride.geojson", so the two never disagree.
+        # A .geojson source is already named right and is left alone.
+        original_name = File.basename(params[:splat].first)
+        download_name = original_name.downcase.end_with?(".geojson") ? original_name : "#{original_name}.geojson"
+        attachment download_name
+      end
       body
     end
 

docs/architecture.adoc

@@ -285,7 +285,23 @@ A `.geojson` upload skips this path entirely — `geojson` reads and
 returns it directly, no cache file, no `Gpx`/`Fit` involved; the file
 tree's cached-file icon (`GEOJSON_ICON`, `public/js/icons.js`) always
 shows for one, since there's no conversion step it could ever be
-waiting on. `Gpx` parses the GPX with REXML: `<wpt>`
+waiting on.
++
+Once a `.gpx`/`.fit` is cached, the tree shows it under its converted
+name instead — `"ride.gpx"` reads as `"ride.gpx.geojson"`, matching
+the real cache file sitting next to it on disk — since the GeoJSON,
+not the original, is what's actually rendered on the map from that
+point on. The original is never deleted or re-parsed once cached, just
+not re-shown as itself; the tree's file name is a real link
+(`GET /api/gpx/file/<path>?download=1`), the only way to get that
+converted form out of the app as an actual file, since the cache is
+otherwise an implementation detail with no name of its own to expose.
+It's an `<a>`, not a `<span>`, specifically so clicking it downloads
+instead of also toggling the row's checkbox — a native `<a>`/`<button>`
+nested inside a `<label>` claims its own click instead of the label
+forwarding it to the associated control, so the two behaviors don't
+fight over the same click. A directly-uploaded `.geojson` keeps its
+own name (nothing to convert) and downloads unchanged. `Gpx` parses the GPX with REXML: `<wpt>`
 waypoints become `Point` features (with `name`, `desc` and `time`
 carried through as properties), each `<trk>` becomes one
 `MultiLineString` feature (one line per `<trkseg>`), and each `<rte>`

public/css/style.css

@@ -360,6 +360,12 @@ html, body {
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
+  color: inherit;
+  text-decoration: none;
+}
+
+.gpx-tree__file-name:hover {
+  text-decoration: underline;
 }
 
 .gpx-tree__kind-icon {

public/js/gpx.js

@@ -271,10 +271,23 @@ export class GpxPanelControl {
     checkbox.type = "checkbox";
     checkbox.checked = this._visible.has(file.path);
     checkbox.addEventListener("change", () => this._toggleFile(file.path, checkbox.checked, checkbox));
-    const name = document.createElement("span");
+    // Once a .gpx/.fit is cached, its converted GeoJSON is the thing that's
+    // actually shown on the map from here on (see GpxStore#geojson) — the
+    // name reflects that (matching the real "<path>.geojson" cache file on
+    // disk) rather than still reading as a plain, un-converted .gpx/.fit.
+    // A direct .geojson upload already ends in .geojson, so it's left
+    // alone. It's an <a>, not a <span>: clicking it downloads that GeoJSON
+    // (?download=1) — the only way to get it out of the app, since the
+    // original .gpx/.fit is never deleted but also never re-shown once
+    // converted. An <a> nested in a <label> doesn't also toggle the
+    // checkbox on click (unlike a plain element), so this doesn't fight
+    // the row's own toggle-on-map behavior.
+    const displayName = file.cached && !file.name.toLowerCase().endsWith(".geojson") ? `${file.name}.geojson` : file.name;
+    const name = document.createElement("a");
     name.className = "gpx-tree__file-name";
-    name.textContent = file.name;
+    name.href = `${gpxFileUrl(file.path)}?download=1`;
-    name.title = file.name;
+    name.textContent = displayName;
+    name.title = `Download ${displayName}`;
     label.appendChild(checkbox);
     (file.kinds || []).forEach((kind) => label.appendChild(this._kindIcon(kind)));
     if (file.cached) label.appendChild(this._cachedIcon());

test/test_app.rb

@@ -72,6 +72,24 @@ class AppTest < Minitest::Test
     assert_equal "Spot", json_body(file_response)["features"][0]["properties"]["name"]
   end
 
+  def test_download_of_a_converted_gpx_names_it_gpx_geojson
+    content = File.read(fixture_path("sample.gpx"))
+    post_file("/api/gpx", filename: "ride.gpx", content: content, env: logged_in_env)
+
+    response = request.get("/api/gpx/file/ride.gpx?download=1")
+    assert_equal 200, response.status
+    assert_includes response.headers["Content-Disposition"], 'filename="ride.gpx.geojson"'
+  end
+
+  def test_download_of_a_native_geojson_keeps_its_own_name
+    content = '{"type":"FeatureCollection","features":[]}'
+    post_file("/api/gpx", filename: "spots.geojson", content: content, env: logged_in_env)
+
+    response = request.get("/api/gpx/file/spots.geojson?download=1")
+    assert_equal 200, response.status
+    assert_includes response.headers["Content-Disposition"], 'filename="spots.geojson"'
+  end
+
   def test_unparseable_gpx_returns_422
     post_file("/api/gpx", filename: "bad.gpx", content: "<gpx><trk unclosed>", env: logged_in_env)