programscode / Leaflet.LayerIndex

Spatial index of layer objects using RTree.js

Leaflet.LayerIndex

Efficient spatial index for Leaflet layers. It works recursively for L.FeatureGroup objects.

Requires the Magnificient RTree.js

Check out the live demo

Usage

On L.Map objects

    L.Map.include(L.LayerIndexMixin);

    var map = L.map(...);
    ...
    var layer = L.GeoJSON(data).addTo(map);
    map.indexLayer(layer);

    // Search visible features for example
    map.on('moveend', function () {
        var shown = map.search(map.getBounds());
        console.log(shown.length + ' objects shown.');
    });

    // remove the spatial index when the layer is unused
    map.unindexLayer(layer);

map.unindexLayer() function accepts an options object as an optional second parameter to define the bounds to be removed from the index. It should have one of the following attributes:

• options.bounds - a leaflet latLngBounds object
• options.latlng - a leaflet latLng object
• options.latlngs - an array of leaflet latLng objects

If no option is provided, the function will use the bounds of the layer's geometry.

Using inherited class

    L.IndexedGeoJSON = L.GeoJSON.extend({
        includes: L.LayerIndexMixin,

        initialize: function (geojson, options) {
            // Decorate onEachFeature to index layers
            var onEachFeature = function (geojson, layer) {
                this.indexLayer(layer);
                if (this._onEachFeature) this._onEachFeature(geojson, layer);
            };
            this._onEachFeature = options.onEachFeature;
            options.onEachFeature = L.Util.bind(onFeatureParse, this);

            // Parent initialization
            L.GeoJSON.prototype.initialize.call(this, geojson, options);
        },

        removeLayer: function (layer) {
          if (this.hasLayer(layer)) {
            this.unindexLayer(layer)
          }
          return window.L.GeoJSON.prototype.removeLayer.call(this, layer)
        }
    });


    var layer = L.IndexedGeoJSON(data).addTo(map);

    var aroundToulouse = layer.searchBuffer(L.latLng([43.60, 1.44]), 0.1);

Changelog

0.0.2

• Add bower.json

0.0.1

• Initial version

Authors