So I'm really new to react and leaflet but all I want to do is basically have the user enter some input, and after they press enter, trigger an event which then flies to the coordinates generated from that input. I am using geocode and the lat long coordinates are successfully generating. However I a not sure how to make the map fly to that location. Here is what I have so far:

import './App.css';
import * as React from "react";
import { ChakraProvider } from "@chakra-ui/react";
import { MapContainer, TileLayer, Marker, Popup, useMapEvents } from 'react-leaflet'
import 'leaflet/dist/leaflet.css'
import Geocode from "react-geocode";
import SearchBar from './SearchBar';

class App extends React.Component {
  constructor(props){
    super(props)
    this.state = {
      position: [43.653225, -79.383186]
    }
  }
  mapRef = React.createRef();

  changePos (pos) {
    this.setState({position: pos});
    this.mapRef.current.flyTo(pos);
  }

  render () {
    return (
      <ChakraProvider resetCSS = {false}>
        <div className = "App">
          <div id="title">
            <h1>
              CovidStopSpots
            </h1>
              <p>A responsive tracker for Covid-19.</p>
          <SearchBar changePos = {this.changePos.bind(this)}></SearchBar>
          </div>
          <div id="map">
            <MapContainer center={this.state.position} zoom={13} scrollWheelZoom={false} ref={this.mapRef}>
              <TileLayer
                attribution='&copy; <a href=";>OpenStreetMap</a> contributors'
                url="https://{s}.tile.openstreetmap/{z}/{x}/{y}.png"
              />
              <Marker position={[43.653225, -79.383186]}>
                <Popup>
                  A pretty CSS3 popup. <br /> Easily customizable.
                </Popup>
              </Marker>
            </MapContainer>
          </div>
      </div>
      </ChakraProvider>
    )
  }
}

export default App;

also the current code is generating this error:

Unhandled Rejection (TypeError): Cannot read property 'flyTo' of null

So I'm really new to react and leaflet but all I want to do is basically have the user enter some input, and after they press enter, trigger an event which then flies to the coordinates generated from that input. I am using geocode and the lat long coordinates are successfully generating. However I a not sure how to make the map fly to that location. Here is what I have so far:

import './App.css';
import * as React from "react";
import { ChakraProvider } from "@chakra-ui/react";
import { MapContainer, TileLayer, Marker, Popup, useMapEvents } from 'react-leaflet'
import 'leaflet/dist/leaflet.css'
import Geocode from "react-geocode";
import SearchBar from './SearchBar';

class App extends React.Component {
  constructor(props){
    super(props)
    this.state = {
      position: [43.653225, -79.383186]
    }
  }
  mapRef = React.createRef();

  changePos (pos) {
    this.setState({position: pos});
    this.mapRef.current.flyTo(pos);
  }

  render () {
    return (
      <ChakraProvider resetCSS = {false}>
        <div className = "App">
          <div id="title">
            <h1>
              CovidStopSpots
            </h1>
              <p>A responsive tracker for Covid-19.</p>
          <SearchBar changePos = {this.changePos.bind(this)}></SearchBar>
          </div>
          <div id="map">
            <MapContainer center={this.state.position} zoom={13} scrollWheelZoom={false} ref={this.mapRef}>
              <TileLayer
                attribution='&copy; <a href="http://osm/copyright">OpenStreetMap</a> contributors'
                url="https://{s}.tile.openstreetmap/{z}/{x}/{y}.png"
              />
              <Marker position={[43.653225, -79.383186]}>
                <Popup>
                  A pretty CSS3 popup. <br /> Easily customizable.
                </Popup>
              </Marker>
            </MapContainer>
          </div>
      </div>
      </ChakraProvider>
    )
  }
}

export default App;

also the current code is generating this error:

Unhandled Rejection (TypeError): Cannot read property 'flyTo' of null

• javascript
• reactjs
• leaflet
• react-leaflet

• why don't you use only set state part to change the position? also read the position from the state in the Marker. you already hardcoded it. – Ehsan Commented Feb 19, 2021 at 7:42

1 Answer 1

In react-leaflet version 3 you can take the map instance using whenCreated prop and then use it to fly to another location when you do not want to use it for a ponent that is MapContainer's child.

this.state = {
      position: [43.653225, -79.383186],
      map: null
 }

Remove ref and use whenCreated prop

<MapContainer center={this.state.position} zoom={13} scrollWheelZoom={false} whenCreated={map => this.setState({ map })}>

and then on your changePos event use this.state.map to fly

 changePos (pos) {
    this.setState({position: pos});
    const {map} = this.state;
    if (map) map.flyTo(pos);
 }