Navigator

A custom web application that serves OpenStreetMap (OSM) data. It has a build process that:

1. Pulls OSM data from the Overpass API for configurable geographic areas and feature types.
2. Merges hand-authored custom layers — zones (polygons) and points of interest — from scripts/custom-layers.mjs.
3. Converts everything to static GeoJSON files.
4. Builds a SvelteKit frontend (with the static adapter) into a plain static site that renders each data source as a toggleable layer on an interactive Leaflet map.

The final output in build/ is a fully self-contained static site — no server runtime required. You can serve it with any static HTTP server (nginx, Apache, python -m http.server, S3/Cloudflare Pages, etc.).

Built With

• SvelteKit (Svelte 5, runes mode)
• @sveltejs/adapter-static — outputs a static site
• Leaflet — interactive map on the frontend
• Overpass API — OSM data source

Quick Start

npm install

# Fetch & convert OSM data into static/data/*.geojson
npm run build:data

# Full production build: (fetch data) + (static site) -> build/
npm run build

# Preview the production build locally
npm run preview

Development

npm run dev         # Vite dev server (your data in static/data is served too)
npm run check       # Type + Svelte checks

Build Process

Command	What it does
npm run build:data	Runs scripts/osm-data.mjs to fetch OSM data → static/data/
npm run build	build:data followed by the SvelteKit static build → build/
npm run preview	Serves the build/ output locally

Data layout

static/data/
├── _index.json              # Manifest of all built layers (drives the UI)
├── <area>.geojson           # One FeatureCollection per Overpass area
└── custom/
    └── <layer>.geojson      # One FeatureCollection per custom zone/POI layer

The frontend loads /data/_index.json, then fetches each layer's GeoJSON and renders it as a toggleable overlay with a legend (top-right). Every layer can be shown/hidden independently.

Configuring Areas & Queries

Edit scripts/osm-data.mjs — the AREAS object describes each area:

• bbox — [south, west, north, east] in decimal degrees.
• queries — a map of name → Overpass QL snippet. Use {{bbox}} as the placeholder for the area's bounding box.
• The script falls back across multiple public Overpass mirrors if one is overloaded, and is polite to the API (short delay between queries).

Example:

parks: `
  way["leisure"="park"]({{bbox}});
  out center tags geom;
`

List configured queries with npm run data -- --queries, or build a single area with npm run data -- --area=tulsa.

Custom Layers (Zones & Points of Interest)

Besides Overpass-fetched data, you can define your own layers by hand in scripts/custom-layers.mjs. This file ships with a couple of example layers (my-places POIs and districts zones) that you can extend or replace.

Each layer has:

• id — unique slug (becomes the output filename)
• name — label shown in the UI legend
• layerType — 'zone' (polygon) or 'poi' (point)
• color — hex color used for markers/fill
• features — array of feature objects

POI (point):

{ name: 'BOK Center', desc: 'Arena & events', lon: -95.9966, lat: 36.1498 }

Zone (polygon — the ring is closed for you):

{
  name: 'Downtown Tulsa',
  desc: 'Rough downtown core',
  polygon: [
    [-96.0000, 36.1300],
    [-95.9900, 36.1300],
    [-95.9900, 36.1600],
    [-96.0000, 36.1600]
  ]
}

Coordinates are [longitude, latitude] (lon first, like GeoJSON). The file also includes a copy-paste TEMPLATE block for adding new layers. After editing, run npm run build:data (or npm run build) to regenerate the static data.

Deployment

The build/ directory is entirely static. Serve it directly:

cd build
python3 -m http.server 8080
# or: nginx -s  listen 8080; root /path/to/build;  (with a fallback to index.html)

Because the site uses a static adapter with prerendering, everything can be hosted on any static file host or CDN.

Repository

Hosted on Gitea: https://gitea.thecookiejar.me/hermes-explorigin/navigator