How to save a completed polygon points leaflet.dra

2020-02-07 17:41发布

问题:

I would like to use leaflet.draw to create outlines of regions. I have managed to get this working ok: https://www.mapbox.com/mapbox.js/example/v1.0.0/leaflet-draw/

Now I'd like to save the data for each polygon to a mysql table. Am a little stuck on how I would go about exporting the data and the format I should be doing it in.

If possible I'd like to pull the data back into a mapbox/leaflet map in the future so guess something like geojson would be good.

回答1:

So you could use draw:created to capture the layer, convert it to geojson then stringify it to save in your database. I've only done this once and it was dirty but worked.

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

  var shape = layer.toGeoJSON()
  var shape_for_db = JSON.stringify(shape);
});


回答2:

If you want to collect the coordinates, you can do it this way:

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

map.on('draw:created', function (e) {

    var type = e.layerType,
        layer = e.layer;

    drawnItems.addLayer(layer);

    var shapes = getShapes(drawnItems);

    // Process them any way you want and save to DB
    ...

});

var getShapes = function(drawnItems) {

    var shapes = [];

    drawnItems.eachLayer(function(layer) {

        // Note: Rectangle extends Polygon. Polygon extends Polyline.
        // Therefore, all of them are instances of Polyline
        if (layer instanceof L.Polyline) {
            shapes.push(layer.getLatLngs())
        }

        if (layer instanceof L.Circle) {
            shapes.push([layer.getLatLng()])
        }

        if (layer instanceof L.Marker) {
            shapes.push([layer.getLatLng()]);
        }

    });

    return shapes;
};


回答3:

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

  var shape = layer.toGeoJSON()
  var shape_for_db = JSON.stringify(shape);
});

// restore
L.geoJSON(JSON.parse(shape_for_db)).addTo(mymap);


回答4:

@Michael Evans method should work if you want to use GeoJSON.

If you want to save LatLngs points for each shape you could do something like this:

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

    if (type === 'circle') {
       latLngs = layer.getLatLng();
    }
    else
       latLngs = layer.getLatLngs(); // Returns an array of the points in the path.

    // process latLngs as you see fit and then save
}


回答5:

Don't forget the radius of the circle

            if (layer instanceof L.Circle) {
                shapes.push([layer.getLatLng()],layer.getRadius())
            }

PS that statement may not get the proper formatting but you see the point. (Or rather the radius as well as the point ;-)



回答6:

Get shares as associative array + circle radius

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

        if (type === 'marker') {
            layer.bindPopup('Call Point!');
        }

        drawnItems.addLayer(layer);

        var shapes = getShapes(drawnItems);

        console.log("shapes",shapes);




    });


    var getShapes = function (drawnItems) {

        var shapes = [];
        shapes["polyline"] = [];
        shapes["circle"] = [];
        shapes["marker"] = [];

        drawnItems.eachLayer(function (layer) {

            // Note: Rectangle extends Polygon. Polygon extends Polyline.
            // Therefore, all of them are instances of Polyline
            if (layer instanceof L.Polyline) {
                shapes["polyline"].push(layer.getLatLngs())
            }

            if (layer instanceof L.Circle) {
                shapes["circle"].push([layer.getLatLng()])
            }

            if (layer instanceof L.Marker) {
                shapes["marker"].push([layer.getLatLng()],layer.getRadius());
            }

        });

        return shapes;
    };


回答7:

For me it worked this:

map.on(L.Draw.Event.CREATED, function (e) {
    map.addLayer(e.layer);
    var points = e.layer.getLatLngs();
  puncte1=points.join(',');
  puncte1=puncte1.toString();
  //puncte1 = puncte1.replace(/[{}]/g, '');
  puncte1=points.join(',').match(/([\d\.]+)/g).join(',')
//this is the field where u want to add the coordinates
$('#geo').val(puncte1);
});