data/hiking_trails.geojson now generates automatically as the last
step of every offline.pmtiles build (PmtilesBuilder.extract_hiking_trails,
best-effort — a failure here doesn't fail the whole build), merged
across all selected countries with cross-border dedup by OSM relation
id (HikingTrails.extract_merged). Served at GET /tiles/hiking_trails.geojson
and GET /api/hiking-trails, fetched client-side only once the overlay
is actually toggled on.
hiking_trails.js now prefers this local file whenever it exists,
regardless of which base map (online/offline) is active — same
"prefer local when available" story as HillshadeControl already uses
for terrain. Offline click hit-tests the real vector layer directly
(queryRenderedFeatures) instead of querying Overpass — instant, no
network. Coordinates are rounded to 5dp to keep the combined file
smaller; colour tag values are normalized against a known-safe set
before ever reaching a style paint property.
Verified extract_merged (new: combines multiple countries' extracts,
dedupes overlapping relations) against two real cached country PBFs
on brick directly, not just fixtures.
No custom Planetiler profile needed after all — Maptool::HikingTrails
runs osmium tags-filter r/route=hiking against the same .osm.pbf
PmtilesBuilder already downloads per country for offline.pmtiles, then
osmium cat -f opl (locations_on_ways=true) to get member-way geometry
back as plain text, no separate node-id lookup table to build.
No general OSM tool stitches a route relation into one line (routes
are a semantic grouping, not a geometry type) — parse_opl does that
walk itself, same as the Overpass-based click handler already does
client-side. Kept pure/testable apart from the two osmium subprocess
calls, mirroring OverpassPois.fetch vs .to_geojson.
rake hiking:trails[pbf,out] to try it by hand against a real cached
extract. Not wired into the actual offline build or rendering yet —
still just a prototype, per TODO.adoc.
randy