React Leaflet: Add Markers Dynamically

Question

How to add markers dynamically to React-Leaflet cards?

I want to add new markers when the user clicks on the map. And I can’t make it work.

import React, { Component } from 'react'
import { render } from 'react-dom';
import Control from 'react-leaflet-control';
import { Map, Marker, Popup, TileLayer, ZoomControl, ScaleControl } from 'react-leaflet';
import './Points.scss'

export default class PointsMap extends Component {
  state = {
    lat: 50.2, 
    lng: 30.2,
    zoom: 13,
  }

  handleClick = (e) => {
    this.addMarker();
  }

  addMarker() {

    // A) Following raises error:  
    var marker3 = L.marker([50.5, 30.5]).addTo(this.refs.map);

    // B) With following marker doesn't appear on map:
    const position2 = [50,30];      
    <Marker map={this.refs.map} position={position2} />
  }

  render () {
    const position = [this.state.lat, this.state.lng]
    return (
      <Map ref='map' center={position} zoom={this.state.zoom} onClick=    {this.handleClick} >
        <ZoomControl position="topright" />
        <ScaleControl position="bottomright" />
        <TileLayer
      attribution='&copy <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
      url='http://{s}.tile.osm.org/{z}/{x}/{y}.png'
    />
    <Marker map={this.refs.map} position={position} >
      <Popup>
        <span>A pretty CSS3 popup. <br /> Easily customizable.</span>
      </Popup>
    </Marker>
  </Map>

    )
  }
}

In addMarker () I am trying to add a new marker. I try to do this in two ways:

AND)

 var marker3 = L.marker([50.5, 30.5]).addTo(this.refs.map);

An error occurs:

 Uncaught TypeError: map.addLayer is not a function
     at NewClass.addTo (leaflet-src.js:3937)
     at PointsMap.addMarker (Points.js?12f5:54)

AT)

const position2 = [50,30];      
    <Marker map={this.refs.map} position={position2} />

It does not add any new marker and does not cause any errors.

Do you have any idea how to add / remove markers dynamically?

Answer 1

-, , , , . - .

, , . , L.marker <Marker>.

:

class SimpleExample extends React.Component {
  constructor() {
    super();
    this.state = {
      markers: [[51.505, -0.09]]
    };
  }

  addMarker = (e) => {
    const {markers} = this.state
    markers.push(e.latlng)
    this.setState({markers})
  }

  render() {
    return (
      <Map 
        center={[51.505, -0.09]} 
        onClick={this.addMarker}
        zoom={13} 
        >
        <TileLayer
          attribution='&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
          url='http://{s}.tile.osm.org/{z}/{x}/{y}.png'
        />
        {this.state.markers.map((position, idx) => 
          <Marker key={`marker-${idx}`} position={position}>
          <Popup>
            <span>A pretty CSS3 popup. <br/> Easily customizable.</span>
          </Popup>
        </Marker>
        )}
      </Map>
    );
  }
}

jsfiddle: https://jsfiddle.net/q2v7t59h/413/

Answer 2

, . , :

leaflet.css

. marker-icon.png marker-shadow.png , L.Marker.prototype.options.icon .

, (style = {{width: '100%', height: '400px'}}) Map

import React from 'react';
import L from 'leaflet';
import 'leaflet/dist/leaflet.css';
import { Map, TileLayer, Marker, Popup } from 'react-leaflet';
import icon from 'leaflet/dist/images/marker-icon.png';
import iconShadow from 'leaflet/dist/images/marker-shadow.png';

class OSMap extends React.Component {
    constructor() {
        super();
        this.state = {
            markers: [[35.6892, 51.3890]],
        };
    }

    addMarker = (e) => {
        const { markers } = this.state;
        markers.pop();
        markers.push(e.latlng);
        this.setState({ markers });
    }

    render() {
        let DefaultIcon = L.icon({
            iconUrl: icon,
            shadowUrl: iconShadow
        });
        L.Marker.prototype.options.icon = DefaultIcon;

        return (
            <div>
                <Map
                    center={[35.6892, 51.3890]}
                    onClick={this.addMarker}
                    zoom={13}
                    maxZoom={18}
                    minZoom={5}   
                    style={{width: '100%',height: '400px'}}
                >
                    <TileLayer
                        attribution='&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
                        url='http://{s}.tile.osm.org/{z}/{x}/{y}.png'
                    />
                    {this.state.markers.map((position, idx) =>
                        <Marker key={'marker-${idx}'} position={position}></Marker>
                    )}
                </Map>
            </div>
        );
    }
}

export default OSMap;