如何将Leaflet-pip插件与纯GeoJSON数据一起使用？

Question

I have trouble with using leaflet-pip: i get geojson data from here: http://polygons.openstreetmap.fr/get_geojson.py?id=1320234&params=0

How should i call leafletPip.pointInLayer with such data? I have several attempts, but it returns empty array, but i know that there are some markers inside those layers.

Answer 1

Just in case, note first that Leaflet-PIP needs an L.GeoJSON group to be passed as 2nd argument. It is trivial to build one from your GeoJSON data ( L.geoJson(myGeoJSONdata) ). Actually, it even just needs an L.LayerGroup .

Then, it seems that Leaflet-PIP does not handle nested Layer Groups.

Your data is made of MultiPolygons, which Leaflet converts into groups of L.Polygon within the L.GeoJSON group. Therefore Leaflet-PIP does not process them.

So you just have to "flatten" your group before being able to use it correctly with Leaflet-PIP. Parse the group and extract all non-group layers into another group.

var gjLayer = L.geoJson(myGeoJSONdata).addTo(map);

var groupOfNonGroup = L.layerGroup();

function copyToGroupOfNonGroup(group) {
  group.eachLayer(function (layer) {
    if (layer instanceof L.LayerGroup) {
      copyToGroupOfNonGroup(layer);
    } else {
      layer.addTo(groupOfNonGroup);
    }
  });
}

copyToGroupOfNonGroup(gjLayer);

var results = leafletPip.pointInLayer([lng, lat], groupOfNonGroup);

Demo: https://plnkr.co/edit/6hRKHHtvWOVdWg4jZ8AJ?p=preview