added geohash support

package.json

@@ -14,6 +14,7 @@
     "leaflet": "^1.9.3",
     "leaflet-draw": "^1.0.4",
     "leaflet-fullscreen": "^1.0.2",
+    "ngeohash": "^0.6.3",
     "ol": "^6.14.1",
     "proj4": "^2.8.0",
     "react": "^18.1.0",

src/App.js

@@ -370,7 +370,7 @@ function App() {
 
       <footer className="footer mt-auto pt-5 pb-4 bg-light">
         <Container>
-          <p className="text-muted">This page parses, visualizes, and shares <a href="https://en.wikipedia.org/wiki/Well-known_text_representation_of_geometry" rel="noreferrer" className="text-muted" target="_blank">WKT</a> (ISO 13249) as well as <a href="https://opengeospatial.github.io/ogc-geosparql/geosparql11/spec.html#_rdfs_datatype_geowktliteral" target="blank" rel="noreferrer" className="text-muted">geo:wktLiteral</a> strings in a variety of coordinate reference systems. Built with <a href="https://openlayers.org/" target="blank" rel="noreferrer" className="text-muted">OpenLayers</a>, <a href="https://leafletjs.com/" target="blank" rel="noreferrer" className="text-muted">Leaflet</a>, <a href="https://trac.osgeo.org/proj4js" target="blank" rel="noreferrer" className="text-muted">Proj4js</a>, <a href="https://github.com/terraformer-js/terraformer" target="blank" rel="noreferrer" className="text-muted">terraformer</a>, and <a href="https://epsg.io/" target="blank" rel="noreferrer" className="text-muted">epsg.io</a>. Use the drawing tools to create your own geometries. Copy as Well-known Binary (WKB) or Extended Well-known Binary (EWKB). Also supports the conversion of H3 indices to WKT.</p>
+          <p className="text-muted">This page parses, visualizes, and shares <a href="https://en.wikipedia.org/wiki/Well-known_text_representation_of_geometry" rel="noreferrer" className="text-muted" target="_blank">WKT</a> (ISO 13249) as well as <a href="https://opengeospatial.github.io/ogc-geosparql/geosparql11/spec.html#_rdfs_datatype_geowktliteral" target="blank" rel="noreferrer" className="text-muted">geo:wktLiteral</a> strings in a variety of coordinate reference systems. Built with <a href="https://openlayers.org/" target="blank" rel="noreferrer" className="text-muted">OpenLayers</a>, <a href="https://leafletjs.com/" target="blank" rel="noreferrer" className="text-muted">Leaflet</a>, <a href="https://trac.osgeo.org/proj4js" target="blank" rel="noreferrer" className="text-muted">Proj4js</a>, <a href="https://github.com/terraformer-js/terraformer" target="blank" rel="noreferrer" className="text-muted">terraformer</a>, and <a href="https://epsg.io/" target="blank" rel="noreferrer" className="text-muted">epsg.io</a>. Use the drawing tools to create your own geometries. Copy as Well-known Binary (WKB) or Extended Well-known Binary (EWKB). Also supports <a href="https://h3geo.org/" rel="noreferrer" className="text-muted" target="_blank">H3</a> index and <a href="https://en.wikipedia.org/wiki/Geohash" rel="noreferrer" className="text-muted" target="_blank">Geohash</a> conversion to WKT.</p>
           <p className="text-muted">Created by <Twitter className="mb-1"/> <a rel="noreferrer" className="text-muted" href="https://twitter.com/PieterPrvst" target="_blank">PieterPrvst</a></p>
         </Container>
       </footer>

src/wkt.js

@@ -5,6 +5,7 @@ import crsList from "./crs";
 import { Geometry } from "@pieterprovoost/wkx";
 import { Buffer } from "buffer";
 import { cellToBoundary } from "h3-js";
+import geohash from "ngeohash";
 
 const USE_WKT = false;
 
@@ -83,13 +84,24 @@ async function transformInput(input) {
     ewkb: null
   }
 
-  // handle H3
+  // handle H3 and geohash
 
   if (input.wkt && (input.wkt.length === 15 || input.wkt.length === 16) && input.wkt.match(/^[0-9a-f]+$/i)) {
     const boundary = cellToBoundary(input.wkt, true);
     const wkt = "POLYGON ((" + boundary.map(x => x[0] + " " + x[1]).join(",") + "))";
     input.wkt = wkt;
     input.epsg = 4326;
+  } else if (input.wkt && input.wkt.match(/^[0-9a-z]+$/)) {
+    const [bottom, left, top, right] = geohash.decode_bbox(input.wkt);
+    const wkt = "POLYGON((" +
+      left + " " + top + ", " +
+      right + " " + top + ", " +
+      right + " " + bottom + ", " +
+      left + " " + bottom + ", " +
+      left + " " + top +
+      "))";
+    input.wkt = wkt;
+    input.epsg = 4326;
   }
 
   // split input, parse EPSG if in WKT