Leaflet.draw retrieve layer type on draw:edited ev

问题:

I'm using the https://github.com/Leaflet/Leaflet.draw plugin and I'm trying to figure out how I can retrieve the layer type of the edited layer.

On the draw:created event, I have the layer and layerType, but on draw:edited (Triggered when saving all edits) I get a list of layers that were edited.

The draw:created event

map.on('draw:created', function (e) {
    var type = e.layerType,
        layer = e.layer;

    if (type === 'marker') {
        // Do marker specific actions
    }

    // Do whatever else you need to. (save to db, add to map etc)
    map.addLayer(layer);
});

The draw:edited event

map.on('draw:edited', function (e) {
    var layers = e.layers;
    layers.eachLayer(function (layer) {
        //do stuff, but I can't check which type I'm working with
        // the layer parameter doesn't mention its type
    });
});

Thank you for your time.

回答1:

You could use instanceof (docs here).

map.on('draw:edited', function (e) {
    var layers = e.layers;
    layers.eachLayer(function (layer) {
        if (layer instanceof L.Marker){
            //Do marker specific actions here
        }
    });
});

回答2:

Be very careful when using instanceof. Leaflet.draw plugin uses standard Leaflet's L.Rectangle. Leaflet's rectangle extends Polygon. Polygon extends Polyline. Therefore, some shapes might give you unexpected results using this method.

var drawnItems = new L.FeatureGroup();
map.addLayer(drawnItems);

... add layers to drawnItems ...

// Iterate through the layers    
drawnItems.eachLayer(function(layer) {

    if (layer instanceof L.Rectangle) {
        console.log('im an instance of L rectangle');
    }

    if (layer instanceof L.Polygon) {
        console.log('im an instance of L polygon');
    }

    if (layer instanceof L.Polyline) {
        console.log('im an instance of L polyline');
    }

});

How do i find out the shape type?

var getShapeType = function(layer) {

    if (layer instanceof L.Circle) {
        return 'circle';
    }

    if (layer instanceof L.Marker) {
        return 'marker';
    }

    if ((layer instanceof L.Polyline) && ! (layer instanceof L.Polygon)) {
        return 'polyline';
    }

    if ((layer instanceof L.Polygon) && ! (layer instanceof L.Rectangle)) {
        return 'polygon';
    }

    if (layer instanceof L.Rectangle) {
        return 'rectangle';
    }

};