add support for zoom-offset to l-tile-layer element

andrewgryan · andrewgryan · commit 656177660a59 · 2025-01-02T16:53:43.000Z
diff --git a/src/l-tile-layer.js b/src/l-tile-layer.js
@@ -39,6 +39,14 @@ class LTileLayer extends LLayer {
     });
     const options = parse(schema, this);
 
+    const zoomOffset = this.getAttribute("zoom-offset");
+    if (zoomOffset) {
+      const number = parseInt(zoomOffset);
+      if (!isNaN(number)) {
+        options["zoomOffset"] = number;
+      }
+    }
+
     // GridLayer options
     const gridOptions = gridLayerOptions(this);
 
diff --git a/src/l-tile-layer.test.js b/src/l-tile-layer.test.js
@@ -76,3 +76,17 @@ it("should support tile-size attribute default value", () => {
   const expected = tileLayer(urlTemplate, {});
   expect(actual).toEqual(expected);
 });
+
+it.each([["-1", -1]])(
+  "should support zoom-offset attribute",
+  (text, zoomOffset) => {
+    const urlTemplate = "/";
+    const el = document.createElement("l-tile-layer");
+    el.setAttribute("url-template", urlTemplate);
+    el.setAttribute("zoom-offset", text);
+    document.body.appendChild(el);
+    const actual = el.layer;
+    const expected = tileLayer(urlTemplate, { zoomOffset });
+    expect(actual).toEqual(expected);
+  },
+);
