From a258df360467eff4b86d1986a017fe83af4c148a Mon Sep 17 00:00:00 2001
From: Maurits van der Schee <maurits@vdschee.nl>
Date: Thu, 4 Jul 2019 02:39:15 +0200
Subject: [PATCH] support tiles in GeoJSON

---
 .../clients/leaflet/geojson-tile-layer.js     | 25 ++++++++++++++-----
 examples/clients/leaflet/vanilla.html         |  1 +
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/examples/clients/leaflet/geojson-tile-layer.js b/examples/clients/leaflet/geojson-tile-layer.js
index c289ee5..f3e99c2 100644
--- a/examples/clients/leaflet/geojson-tile-layer.js
+++ b/examples/clients/leaflet/geojson-tile-layer.js
@@ -32,12 +32,13 @@
 
         updateLayers: function(url, geoData) {
             if (geoData.type == 'FeatureCollection'){
-                for (var i=0;i<geoData.features.length;i++) {
-                    var id = geoData.features[i].id;
-                    if (!this.features[id]) {
-                        this.layer.addData(geoData.features[i]);
-                        this.features[id] = true;
-                    }
+                geoData = geoData.features;
+            }
+            for (var i=0;i<geoData.length;i++) {
+                var id = geoData[i].id;
+                if (!this.features[id]) {
+                    this.layer.addData(geoData[i]);
+                    this.features[id] = true;
                 }
             }
             if (!this.cache[url]) {
@@ -49,9 +50,11 @@
             L.GridLayer.prototype.onAdd.call(this, map); 
             map.addLayer(this.layer);
             this.map = map;
+            map.on('zoomanim', this.onZoomAnim.bind(this));
         },
 
         onRemove(map) {
+            map.off('zoomanim', this.onZoomAnim.bind(this));
             this.map = null;
             map.removeLayer(this.layer)
             L.GridLayer.prototype.onRemove.call(this, map);
@@ -74,6 +77,16 @@
             return request;
         },
 
+        onZoomAnim: function (e) {
+            var zoom = e.zoom;
+            if ((this.options.maxZoom && zoom > this.options.maxZoom) ||
+                (this.options.minZoom && zoom < this.options.minZoom)) {
+                this.map.removeLayer(this.layer);
+            } else {
+                this.map.addLayer(this.layer);
+            }
+        },
+
     });
 
     L.geoJSONTileLayer = function (url, options) {
diff --git a/examples/clients/leaflet/vanilla.html b/examples/clients/leaflet/vanilla.html
index bb91c9a..cb83e9b 100644
--- a/examples/clients/leaflet/vanilla.html
+++ b/examples/clients/leaflet/vanilla.html
@@ -28,6 +28,7 @@
 	}).addTo(mymap);
 
 	L.geoJSONTileLayer('http://localhost:8000/src/geojson/countries?filter=id,lt,3&tile={z},{x},{y}', {
+		minZoom: 3,
 		maxZoom: 18,
 	}).addTo(mymap);
 </script>