A geographic extension for YASGUI. This plugin allows the visualisation of SPARQL results on a map. It depends on Leaflet and now uses betterknown instead of wellknown.
This package extends the YASGUI (Yet Another SPARQL GUI) interface with geographic data visualization capabilities.
- Geographic data visualization
- Integration with YASGUI
- On-the-fly reprojection using proj4 (and automatic fetching of epsg.io for unknown SRIDs).
You need to have a YasGUI installed. You can use @zazuko/yasgui or yasgui. See instructions on their respective pages to get started with that package.
npm install @zazuko/yasgui
npm install git+https://github.com/Thib-G/yasgui-geo-tg.gitimport GeoPlugin from 'yasgui-geo-tg';
import '@zazuko/yasgui/build/yasgui.min.css';
import Yasgui from '@zazuko/yasgui';
//Register the plugin to Yasr
Yasgui.Yasr.registerPlugin('geo', GeoPlugin);Launch any SPARQL query on a GeoSPARQL enabled endpoint returning geometries as WKT literals (http://www.opengis.net/ont/geosparql#wktLiteral) and select the "geo" plugin in the results area.
Here's an example SPARQL query:
PREFIX geo: <http://www.opengis.net/ont/geosparql#>
PREFIX geof: <http://www.opengis.net/def/function/geosparql/>
PREFIX spatialf: <http://jena.apache.org/function/spatial#>
# Test transforming between coordinate systems using Jena vendor functions
SELECT * WHERE {
VALUES (?name ?lat ?lon ?wktColor) {
("Antwerpen Centraal" 51.2133 4.4231 "blue")
("Charleroi Central" 50.4050 4.4396 "red")
("Leuven Station" 50.8830 4.7147 "green")
}
# Create point geometry from coordinates
BIND(STRDT(CONCAT("POINT(", STR(?lon), " ", STR(?lat), ")"), geo:wktLiteral) AS ?point_no_crs_defined)
BIND(STRDT(CONCAT("SRID=4326;POINT(", STR(?lon), " ", STR(?lat), ")"), geo:wktLiteral) AS ?point_ewkt_4326)
BIND(STRDT(CONCAT("<http://www.opengis.net/def/crs/EPSG/0/4326> POINT(", STR(?lat), " ", STR(?lon), ")"), geo:wktLiteral) AS ?point_opengis_4326)
BIND(spatialf:transformSRS(?point_opengis_4326, "http://www.opengis.net/def/crs/EPSG/0/25831") AS ?point_utm_zone_31N)
BIND(spatialf:transformSRS(?point_opengis_4326, "http://www.opengis.net/def/crs/EPSG/0/31370") AS ?point_lambert_belge_72)
BIND(?name AS ?wktTooltip)
BIND(CONCAT("Station: ", ?name) AS ?wktLabel)
}After building the project (or downloading the release assets), you can include the minified IIFE bundle directly in a plain HTML page. The bundle exposes the plugin on a global variable named YasguiGeoTg (or YasguiGeoTg.default depending on how the bundler/runtime handles default exports).
Minimal example:
<!doctype html>
<html>
<head>
<meta charset="utf-8" />
<title>YASGUI Geo Demo</title>
<!-- Leaflet CSS & JS (from CDN) -->
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css" />
<script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
<!-- YASGUI CSS & JS (from CDN or local build) -->
<link rel="stylesheet" href="https://unpkg.com/@zazuko/yasgui@4.6.0/build/yasgui.min.css" />
<script src="https://unpkg.com/@zazuko/yasgui@4.6.0/dist/yasgui.min.js"></script>
</head>
<body>
<div id="yasgui" style="height:600px"></div>
<!-- Plugin bundle built with esbuild -->
<script src="/dist/yasgui-geo-tg.min.js"></script>
<script>
// The bundle exposes the plugin constructor on window.YasguiGeoTg
const GeoPlugin = window.YasguiGeoTg && (window.YasguiGeoTg.default || window.YasguiGeoTg);
// Register the plugin with YASR before creating Yasgui
Yasgui.Yasr.registerPlugin('geo', GeoPlugin);
const yasgui = new Yasgui(document.getElementById('yasgui'), {
requestConfig: { endpoint: 'https://dbpedia.org/sparql' },
yasr: { pluginOrder: ['table','response','geo'], defaultPlugin: 'geo' },
});
</script>
</body>
</html>In order to test and develop the plugin, you can use the demo environment provided.
Clone this repository locally and install its dependencies:
npm installThen run the local dev server (uses vite):
npm run devThen go to http://localhost:5173/demo/index.html to see the demo. This environment will be updated while you make changes to the code. You can also add this configuration in VS Code (in .vscode/launch.json) to launch the demo directly from the debugger:
{
"version": "0.2.0",
"configurations": [
{
"type": "msedge",
"request": "launch",
"name": "Launch Demo",
"url": "http://localhost:5173/demo/index.html",
"webRoot": "${workspaceFolder}"
}
]
}- You can try it here: https://linked-data.goelff.be/yasgui/
- Or click HERE to see MathiasVDA's crazy query to convert a geojson file to RDF and then to
http://www.opengis.net/ont/geosparql#wktLiteralusing Sparql Anything.
- Supported SRIDs (embedded):
4326,3857,31370,4258,3035,25832,25833. - Behavior: The plugin accepts WKT literals (and Geosparql WKT strings) and will following the GeoSPARQL standard. Note that when EPSG:4326 is specified, the coordinate order should be latitude, longitude. When it isn't specified, the order should be longitude, latitude.
- Auto download of CRS: CRS definitions will be automatically downloaded from
https://epsg.io/when not embedded (see next section).
- The package includes embedded proj4 definitions for common SRIDs listed above and registers them at module initialization.
- For SRIDs not embedded, the helper
ensureProjDef(srid)can be used to fetch a proj4 definition fromhttps://epsg.io/<srid>.proj4and register it withproj4at runtime. After fetching, re-render the plugin (call the plugin'sdraw()orupdateMap()method) to apply reprojection.
API notes:
ensureProjDef(srid): Async helper to fetch and register a proj4 definition for a numeric SRID (exported).
Example (in application code):
import { ensureProjDef } from 'yasgui-geo-tg';
// ensure EPSG:25832 is registered, then redraw the plugin
await ensureProjDef('25832');
geoPlugin.draw();Contributions are welcome! Please feel free to submit a Pull Request.
MIT
Thibaut Goelff