JS MapLibre Adapter: autodetect minzoom/maxzoom, clean up hacky loading syntax [#48]

js/adapters.ts

@@ -62,6 +62,27 @@ export class Protocol {
   }
 
   tile = (params: any, callback: any) => {
+    if (params.type == "json") {
+      const pmtiles_url = params.url.substr(10);
+      let instance = this.tiles.get(pmtiles_url);
+      if (!instance) {
+        instance = new PMTiles(pmtiles_url);
+        this.tiles.set(pmtiles_url, instance);
+      }
+
+      instance.getHeader().then((h) => {
+        const tilejson = {
+          tiles: [params.url + "/{z}/{x}/{y}"],
+          minzoom: h.minZoom,
+          maxzoom: h.maxZoom,
+        };
+        callback(null, tilejson, null, null);
+      });
+
+      return {
+        cancel: () => {},
+      };
+    } else {
       const re = new RegExp(/pmtiles:\/\/(.+)\/(\d+)\/(\d+)\/(\d+)/);
       const result = params.url.match(re);
       const pmtiles_url = result[1];
@@ -81,19 +102,28 @@ export class Protocol {
         controller.abort();
       };
 
-    instance.getZxy(+z, +x, +y, signal).then((resp) => {
+      instance
+        .getZxy(+z, +x, +y, signal)
+        .then((resp) => {
           if (resp) {
-        callback(null, new Uint8Array(resp.data), resp.cacheControl, resp.expires);
+            callback(
+              null,
+              new Uint8Array(resp.data),
+              resp.cacheControl,
+              resp.expires
+            );
           } else {
             callback(null, new Uint8Array(), null, null);
           }
-    }).catch((e) => {
+        })
+        .catch((e) => {
           if (e.name !== "AbortError") {
             throw e;
           }
         });
       return {
-      cancel: cancel
+        cancel: cancel,
       };
+    }
   };
 }