Control zoom level when using geolocate.trigger() in mapbox gl js - javascript

I am using mapbox-gl in a react app to render an interactive map. On map load, I want to center the map on the user's location while keeping the current level of zoom. Centering on the user's location works fine with geolocate.trigger(); but the map automatically zooms way out to the continent level. Here is a simplified version of the map component of the app. I start by setting a hard-coded center point in New York which works fine, and then when trigger() runs, it gets zoomed way out. I've tried fiddling with all the properties of the geolocate object, but none of them has any effect on the zoom that trigger() goes to, and trigger doesn't seem to take any arguments. Note that I've had to remove my mapboxgl.accessToken for security reasons.
As a side note, I'm also trying to get rid of the larger blue location confidence circle but I also can't seem to do that despite setting showAccuracyCircle: false. Any mapbox tips?
React component:
import React from 'react';
import mapboxgl from 'mapbox-gl';
import './map.css';
mapboxgl.accessToken = 'ACCESS_TOKEN_STRING_GOES_HERE';
export class Map extends React.Component {
constructor(props) {
super(props);
this.state = {
lng: -73.9392,
lat: 40.8053,
zoom: 17.5
};
}
componentDidMount() {
const map = new mapboxgl.Map({
container: this.mapContainer,
style: 'mapbox://styles/mapbox/streets-v11',
center: [this.state.lng, this.state.lat],
zoom: this.state.zoom
});
const geolocate = new mapboxgl.GeolocateControl({
container: this.geolocateContainer,
positionOptions: {enableHighAccuracy: true},
fitBoundsOptions: {linear: true, maxZoom: 10},
trackUserLocation: true,
mapboxgl: mapboxgl,
showAccuracyCircle: false
})
map.on('load', () => {
geolocate.trigger();
});
map.addControl(geolocate);
}
render() {
return (
<div>
<div ref={element => this.geolocateContainer = element} className='mapButtons' />
<div ref={el => this.mapContainer = el} className='mapContainer' />
</div>
)
}
}
Here is a code pen I put together that illustrates the issue if you insert your own mapboxgl.accessToken. If you look closely, right when the page loads up, a default view is shown at the coordinates and zoom level provided in this.state. But then it immediately centers on the user's location (this is the desired behavior) and zooms way out (I don't want to zoom out). You'll need to give the codepen page permission to access your location to see this.
https://codepen.io/lexandermorgan/pen/ZEWEzze

At the risk of pointing out the obvious, you should be setting minZoom, not maxZoom:
fitBoundsOptions: {linear: true, minZoom: map.getZoom()},
Also, if you're not actually using the geolocation tracking features, or need the control itself, it may be simpler to just use the browser's geolocation API directly:
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(e =>
map.jumpTo({ center: [e.coords.longitude, e.coords.latitude]}))
}

I found a slightly different work-around for this. It uses ReactMapGL instead of MapboxGL. The thing that seems to have made the difference is to pass a zoom parameter to a temporary geocoderDefaultOverrides object and then unpacking the viewport and then that object into the return object in handleGeocoderViewportChange. Here are the relevant parts:
handleGeocoderViewportChange = viewport => {
const geocoderDefaultOverrides = { transitionDuration: 0, zoom: 16 };
return this.handleViewportChange({
...viewport,
...geocoderDefaultOverrides
});
};
Then in render:
<Geocoder
mapRef={this.map_ref}
mapboxApiAccessToken={MBAccessToken}
onViewportChange={this.handleGeocoderViewportChange}
viewport={this.state.viewport}
/>

Related

Coordinates array from PolylineMeasure plugin (react leaflet)

I have 3 files:
1.
PolylineMeasure.jsx
import { MapControl, withLeaflet } from "react-leaflet";
import * as L from "leaflet";
class PolylineMeasure extends MapControl {
createLeafletElement() {
return L.control.polylineMeasure({
position: "topleft",
unit: "metres",
showBearings: true,
clearMeasurementsOnStop: false,
showClearControl: true,
showUnitControl: true,
});
}
componentDidMount() {
const { map } = this.props.leaflet;
const polylineMeasure = this.leafletElement;
polylineMeasure.addTo(map);
}
}
export default withLeaflet(PolylineMeasure);
Map.jsx
import { Map, TileLayer } from "react-leaflet";
import PolylineMeasure from "./PolylineMeasure";
import "leaflet/dist/leaflet.css";
import "leaflet/dist/leaflet.css";
import "leaflet.polylinemeasure/Leaflet.PolylineMeasure.css";
import "leaflet.polylinemeasure/Leaflet.PolylineMeasure";
const Leaflet = () => {
return (
<>
<Map
center={[52.11, 19.21]}
zoom={6}
scrollWheelZoom={true}
style={{ height: 600, width: "50%" }}
>
<TileLayer
attribution='© OpenStreetMap contributors'
url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
/>
<PolylineMeasure />
</Map>
</>
);
};
export default Leaflet;
I'm using nextjs so I had to import without SSR.
home.js
import dynamic from "next/dynamic";
function HomePage() {
const Map = dynamic(() => import("../components/Map"), {
loading: () => <p>A map is loading</p>,
ssr: false,
});
return <Map />;
}
export default HomePage;
https://github.com/ppete2/Leaflet.PolylineMeasure
Using demos in link above, I was able to log an array of coorfinates like this:
{ ... }
polylineMeasure.addTo(map);
function debugevent() {
polylineMeasure._arrPolylines[0].arrowMarkers.map((el) => {
console.log(el._latlng);
});
}
map.on("polylinemeasure:toggle", debugevent);
How can I access these coordinates in nextjs (home.js file)?
How to render PolylineMeasure (Map.jsx file) already with coordinates by passing down an array as props?
So this is about 2 things: lifting up state, and capturing Leaflet.Polyline's internal events.
First, let's keep track of a state variable in Home.js, and pass its setter down into the map component:
function HomePage() {
const [pointarray, setPointarray] = useState()
const Map = dynamic(() => import("../components/Map"), {...})
return <Map setPointarray={setPointarray} />;
}
Now in Map, we need to get a reference to the underlying leaflet map so that we can attach some event handlers. You're using createLeafletElement and withLeaflet, so I assume you're using reat-leaflet version 2. (I recommend updating to v3 when you can).
const Leaflet = ({ setPointarray }) => {
const mapRef = React.useRef()
useEffect(() => {
if (mapRef && mapRef.current){
mapRef.current.leafletElement.on(
'polylinemeasure:finish',
currentLine => setPointarray(currentLine.getLatLngs())
)
}
}, [mapRef])
return (
<>
<Map
ref={mapRef}
...
>
<TileLayer ... />
<PolylineMeasure />
</Map>
</>
);
};
What happens here is that a ref is attached to your Map component, which references the underlying leaflet L.map instance. When that ref is ready, the code inside the useEffect if statement runs. It gets the map instance from mapRef.current.leafletElement, and attaches an event handler based on Leaflet.PolylineMeasure's events, specifically the event of when a drawing is complete. When that happens, it saves the drawn line to the state variable, which lives in the Home component.
There are a lot of variations on this, it just depends on what you're trying to do exactly. As far as feeding preexisting polyline coordinates down to PolylineMeasurer as props, I couldn't find any examples of that even with the vanilla leaflet PolylineMeasurer. I found a comment from the plugin author saying that "restoring of drawed measurements is not possible", which is essentially what we're talking about doing by passing props down to that component. I'm sure it can be done by digging into the source code and programmatically drawing a polyline, but I've run out of time, I'll try to revisit that later.
react-leaflet version 3 answer
As per request, here's how to do this with react-leaflet v3, while initializing the polylinemeasurer with data passed down as props.
Create custom react-leaflet v3 control
Creating custom components with react-leaflet is easier than ever. Take a look at createcontrolcomponent. If you're not used to reading these docs, it boils down to this: to create a custom control component, you need to make a function that returns the leaflet instance of the control you want to make. You feed that function to createcontrolcomponent, and that's it:
import { createControlComponent } from "#react-leaflet/core";
const createPolylineMeasurer = (props) => {
return L.control.polylineMeasure({ ...props });
};
const PolylineMeasurer = createControlComponent(createPolylineMeasurer);
export default PolylineMeasurer;
Altering the original plugin to seed data
However, in our case, we want to add some extra logic to pre-seed the PolylineMeasurer with some latlngs that we pass down as a prop. I put in a pull request to the original plugin to add a .seed method. However, in the case of react-leaflet, we need to be more careful than using the code I put there. A lot of the methods required to draw polylines are only available after the L.Control.PolylineMeasure has been added to the map. I spent probably way too much time trying to figure out where in the react/react-leaflet lifecyle to intercept the instance of the polylineMeasure after it had been added to the map, so my eventual solution was to alter the source code of Leaflet.PolylineMeasure.
In the onAdd method, after all the code has run, we add in this code, which says that if you use a seedData option, it will draw that seed data once the control is added to the map:
// inside L.Control.PolylineMeasure.onAdd:
onAdd: function(map) {
// ... all original Leaflet.PolylineMeasure code here ...
if (this.options.seedData) {
const { seedData } = this.options;
seedData.forEach((polyline) => {
// toggle draw state on:
this._toggleMeasure();
// start line with first point of each polyline
this._startLine(polyline[0]);
// add subsequent points:
polyline.forEach((point, ind) => {
const latLng = L.latLng(point);
this._mouseMove({ latLng });
this._currentLine.addPoint(latLng);
// on last point,
if (ind === polyline.length - 1) {
this._finishPolylinePath();
this._toggleMeasure();
}
});
});
}
return this._container;
}
This code programatically calls all the same events that would be called if a user turned on the control, clicked around, and drew their lines that way.
Tying it together
So now our <PolylineMeasurer /> component takes as its props the options that would be fed to L.control.polylineMeasure, in addition to a new optional prop called seedData which will cause the map to be rendered with that seedData:
const Map = () => {
return (
<MapContainer {...mapContainerProps}>
<TileLayer url={url} />
<PolylineMeasurer
position="topleft"
clearMeasurementsOnStop={false}
seedData={seedData}
/>
</MapContainer>
);
};
Working Codesandbox
Caveat
If by some other mechanism in your app the seedData changes, you cannot expect the PolylineMeasurer component to react in the same way that normal React components do. In create leaflet, this control is added to the map once with the options you feed it, and that's it. While some react-leaflet-v3 component factory functions come with an update paramter, createcontrolcomponent does not (i.e. its first argument is a function which creates a control instance, but it does not accept a second argument to potentially update the control instance like, say, createlayercomponent does).
That being said, you can apply a key prop to the PolylineMeasurer component, and if your seedData is changed somewhere else in the app, also change the key, and the PolylineMeasurer will be forced to rerender and draw your new data.

How do I get to the updated path of an editable PolyLine from react-google-maps/api?

I'm using the react-google-maps/api library, and I have an application where I need the user to edit a Polyline.
The problem I'm having is grabbing the path of the polyline after the user has finished editing.
If I use native react components, the path returned on the props from the polyline is the original path of the line - not the one edited by the user.
The code below is a cutdown version of where I'm trying to get the path of the line from the react component. If you try it and edit the line, the return array is the original path. I've seen some examples using the getPath() method, but I just can't seem to get this to work on the React component (ie polylineRef.current.getPath() returns a no function error.
How should I be getting the path information of the edited line?
import React, { Fragment, useRef } from "react";
import { GoogleMap, Polyline, useLoadScript } from "#react-google-maps/api";
const MapTest = (props) => {
const polylineRef = useRef();
const mapRef = useRef();
const mapContainerStyle = {
width: "80vw",
height: "80vh",
};
const showPath = () => {
console.log(polylineRef.current.props.path); //What should be here to show the edited path if its possible to access?
};
const { isLoaded, loadError } = useLoadScript({
googleMapsApiKey: process.env.REACT_APP_GOOGLE_KEY,
});
const centre = { lat: 51.999889, lng: -0.98807 };
if (loadError) return "Error loading Google Map";
if (!isLoaded) return "Loading Maps....";
console.log(polylineRef.current.props.path);
return (
<Fragment>
<GoogleMap
mapContainerStyle={mapContainerStyle}
ref={mapRef}
zoom={10}
center={centre}
>
<Polyline
ref={polylineRef}
key={1}
path={[
{ lat: 51.9298274729133, lng: -1.0446431525421085 },
{ lat: 51.98483618577529, lng: -1.2423970587921085 },
]}
options={{ editable: true, strokeColor: "#ff0000" }}
/>
</GoogleMap>
<button
onClick={(event) => {
showPath(event);
}}
>
Show Path in Console
</button>
</Fragment>
);
};
export default MapTest;
If I use the native google API, then I can see the updated path, but I can't get a reference to the map created by the map to place the polyline onto.
If I can't access the edited path through the react component, how should I provide a reference to the google maps native API, so when I do
polyline = new google.maps.Polyline(//polyline options)
polyline.setMap(map) //Where do I get the handle for this map to put it on the map above?
/*I've tried using mapRef.current (not a map instance) and
mapRef.current.getInstance() - this makes the original map disappear, for reasons I don't understand*/
When I build this using the native API, I can access the edited path using the getPath() method, but I can't render this polyline on the component rendered above.
Other than building the map out of the native API I'm struggling to do this at the moment - but the benefits of the ease of rendering of React make me want to continue down this path for a while longer - is anyone able to help please?
I think this is what you are trying to achieve:
https://codesandbox.io/s/snowy-night-ony59?file=/src/App.js
My answer is based on:
https://codesandbox.io/s/reactgooglemapsapi-editing-a-polygon-popr2?file=/src/index.js:2601-2845
which I found by googling: react-google-maps-api editable polygon
Basically just copying and pasting the code referred by Daniele Cordano
import React, { useState, useRef, useCallback } from "react";
import ReactDOM from "react-dom";
import { LoadScript, GoogleMap, Polygon } from "#react-google-maps/api";
import "./styles.css";
// This example presents a way to handle editing a Polygon
// The objective is to get the new path on every editing event :
// - on dragging the whole Polygon
// - on moving one of the existing points (vertex)
// - on adding a new point by dragging an edge point (midway between two vertices)
// We achieve it by defining refs for the google maps API Polygon instances and listeners with `useRef`
// Then we bind those refs to the currents instances with the help of `onLoad`
// Then we get the new path value with the `onEdit` `useCallback` and pass it to `setPath`
// Finally we clean up the refs with `onUnmount`
function App() {
// Store Polygon path in state
const [path, setPath] = useState([
{ lat: 52.52549080781086, lng: 13.398118538856465 },
{ lat: 52.48578559055679, lng: 13.36653284549709 },
{ lat: 52.48871246221608, lng: 13.44618372440334 }
]);
// Define refs for Polygon instance and listeners
const polygonRef = useRef(null);
const listenersRef = useRef([]);
// Call setPath with new edited path
const onEdit = useCallback(() => {
if (polygonRef.current) {
const nextPath = polygonRef.current
.getPath()
.getArray()
.map(latLng => {
return { lat: latLng.lat(), lng: latLng.lng() };
});
setPath(nextPath);
}
}, [setPath]);
// Bind refs to current Polygon and listeners
const onLoad = useCallback(
polygon => {
polygonRef.current = polygon;
const path = polygon.getPath();
listenersRef.current.push(
path.addListener("set_at", onEdit),
path.addListener("insert_at", onEdit),
path.addListener("remove_at", onEdit)
);
},
[onEdit]
);
// Clean up refs
const onUnmount = useCallback(() => {
listenersRef.current.forEach(lis => lis.remove());
polygonRef.current = null;
}, []);
console.log("The path state is", path);
return (
<div className="App">
<LoadScript
id="script-loader"
googleMapsApiKey=""
language="en"
region="us"
>
<GoogleMap
mapContainerClassName="App-map"
center={{ lat: 52.52047739093263, lng: 13.36653284549709 }}
zoom={12}
version="weekly"
on
>
<Polygon
// Make the Polygon editable / draggable
editable
draggable
path={path}
// Event used when manipulating and adding points
onMouseUp={onEdit}
// Event used when dragging the whole Polygon
onDragEnd={onEdit}
onLoad={onLoad}
onUnmount={onUnmount}
/>
</GoogleMap>
</LoadScript>
</div>
);
}
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);
For some reason, the useRef hook doesn't accept the function getPath/getPaths() with the typescript error : TS2339: Property 'getPath' does not exist on type 'MutableRefObject'
const handleNewPolygonPath = useCallback(() => {
const newPath = polygonRef.getPath();
dispatch(setNewPolygonPath(newPath));
console.log(newPolygonPath);
}, [dispatch, newPolygonPath]);

ReactJS and Google Maps - Displaying Markers

I'm React newbie so maybe asking a stupid question, but this has got me perplexed. As part of my learning I'm building a three component application - a parent About, and two children (GoogleMap and MapMarkerDetails). The parent does the data coordination and one child shows a google map with two markers as default, the other child shows details of the markers when it is clicked.
I am now adding functionality to add a new marker when the map is clicked. Most of the functionality works - the maps is draw, the default markers are added, and when one of the markers is clicked, this calls a function on the parent class which updates its state and this is propagated to the MapMarkerDetails element and a simple message is displayed.
Here is the parent class which I have commented to help understanding:
import React, { Component } from 'react';
import GoogleMap from './GoogleMap'
import MapMarkerDetails from './MapMarkerDetails'
class About extends Component {
state = {
markers: [{
position: { lat: 51.438759, lng: -2.864514 },
label: 'A',
map: null,
}, {
position: { lat: 51.433636, lng: -2.868734 },
label: 'B',
map: null,
}],
greeting: 'HelloA'
}
showMarkerInfo = (label) => {
this.setState({greeting: ('Hello ' + label)})
}
/*
Adding a new Marker
This function is called from the child element GoogleMap
However, the setState(...) dosn't seem to propogate down to the GoogleMap element.
*/
addMarker = (latlng) => {
let newMarker = [{
position: { lat: latlng.lat(), lng: latlng.lng() },
label: 'New',
map: null,
}];
/* Creates a new array for updating state. Is this the best way to do this */
let markers = [...this.state.markers, ...newMarker]
this.setState({markers});
console.log(this.state) // This shows the added marker
}
render() {
return (
<div className="container">
<h4 className="center">About</h4>
<MapMarkerDetails details={this.state.greeting}/>
<GoogleMap markers={this.state.markers} clickedMarker={this.showMarkerInfo} addMarker={this.addMarker}/>
</div>
)
}
}
export default About;
Here is the class that displays Google Map and the markers:
import React, { Component } from 'react';
class GoogleMap extends Component {
constructor(props) {
super(props);
this.googleMapRef = React.createRef(); // Create a referance for Google Map to draw to
console.log('Constructore')
}
componentDidMount(){
console.log('componentDidMount')
/* Create the Map */
let googleMap = new window.google.maps.Map(this.googleMapRef.current, {
zoom: 15,
center: {
lat: 51.436411,
lng: -2.861980,
},
disableDefaultUI: true,
})
this.placeMMarkers(googleMap) // Place the markers
this.addMapListner(googleMap) // Define a click listener to place new markers
}
/* Place the markers */
placeMMarkers = (googleMap) => {
this.props.markers.forEach((m) => {
m.map = googleMap;
let marker= new window.google.maps.Marker(m)
marker.addListener('click', () => { this.props.clickedMarker(m.label); });
}
);
}
/* Map listeners */
addMapListner = (googleMap) => {
googleMap.addListener('click', (e) => {
this.props.addMarker(e.latLng)
})
}
render() {
console.log('render: ' + this.props.markers) // This is showing the added markers
return (
<div
id="google-map"
ref={this.googleMapRef}
style={{ width: '800px', height: '400px', float: 'left' }}>
</div>
)
}
}
export default GoogleMap
I've added console logging to each function so I can follow what is happening.
Here is the MapMarkerDetails which displays a simple message when an marker is clicked. This all works fine.
import React, { Component } from 'react';
class MapMarkerDetails extends Component {
render(){
return (
<div style={{width: '100px', height: '400px', backgroundColor: 'gray', float: 'left'}}>
{this.props.details}
</div>
)
}
}
export default MapMarkerDetails
Description of the Problem
When the user clicks on the map (not a marker) this invokes the function addMarker which is passed down from the parent About class (snippet below). In the addMarker function of About the lat/lng is passed in. This represents where the user clicked. This is converted into a marker data object, then a new array is created which contains the default markers and the new one. I'm not sure if my new array creation is done in the best way - if not let me know.
Once the new array is created, we update the components state with this.setState({markers}). I thought this would lead to a re-render() and an redrawing of the map with the added marker. But not.
addMarker = (latlng) => {
let newMarker = [{
position: { lat: latlng.lat(), lng: latlng.lng() },
label: 'New',
map: null,
}];
/* Creates a new array for updating state. Is this the best way to do this */
let markers = [...this.state.markers, ...newMarker]
this.setState({markers});
console.log(this.state) // This shows the added marker
}
Something happens that results in the render() function of GoogleMap being called, but only the original markers are shown. The data is passed down to the GoogleMap component because I can see the output of console.log('render: ' + this.props.markers). But how do I get ALL the markers to load?
Please advise on what is the best way to for About to pass data to GoogleMap such that it can add in the new marker.
Just like you use componentDidMount to imperatively add the markers when the map is first loaded, you should use componentDidUpdate to do the same thing when the props change. In your GoogleMap component:
componentDidUpdate() {
this.placeMMarkers()
}
Rather than passing googleMap as an argument, I would set it as an instance variable in componentDidMount:
this.googleMap = new window.google.maps.Map(...
and then change placeMMarkers to use this.googleMap:
placeMMarkers = () => {
this.props.markers.forEach((m) => {
m.map = this.googleMap;
// ...
Since you are attaching an event handler in placeMMarkers, you should also add some logic to distinguish between new markers and existing ones, to avoid adding multiple event handlers to existing markers.
In response to your question about how best to set the state, I think what you've got is fine but you don't need to put the new marker inside an array:
let newMarker = {
position: { lat: latlng.lat(), lng: latlng.lng() },
label: 'New',
map: null,
};
let markers = [...this.state.markers, newMarker]

React google maps re-render issue using onBoundsChanged

I've got a project i'm working on where I use react google maps, however I've run into an issue where when I get the onBoundsChanged event and set state in the callback, it goes into a permanent loop of re rendering. I can only assume somehow that when the component re-renders after I call setState, it sets a new bounds and that will then re-trigger the callback and setState again, in form of an infinitely recursive loop.
import React from 'react'
import { compose, withProps, withStateHandlers, withState, withHandlers } from "recompose";
import {
withScriptjs,
withGoogleMap,
GoogleMap,
Marker
} from"react-google-maps";
import HouseDetails from './house/HouseDetails'
const { InfoBox } = require("react-google-maps/lib/components/addons/InfoBox");
class Map extends React.Component{
constructor(props){
super(props)
this.state = {
zoom: 15,
bounds: null
}
this.map = React.createRef()
this.onBoundsChanged = this.onBoundsChanged.bind(this)
this.onZoomChanged = this.onBoundsChanged.bind(this)
}
componentWillReceiveProps(test){
}
onBoundsChanged(){
this.setState({bounds: this.map.current.getBounds()}, ()=> console.log('update'))
let bounds = this.map.current.getBounds()
let realBounds = {lat:{west: bounds.ga.j, east: bounds.ga.l}, lon: {north: bounds.ma.j, south: bounds.ma.l}}
console.log(realBounds)
}
onZoomChanged(){
this.setState({zoom: this.map.current.getZoom()})
}
componentDidUpdate(){
console.log('hm')
}
render(){
return (
<GoogleMap
defaultZoom={15}
ref={this.map}
onZoomChanged={this.onZoomChanged}
onBoundsChanged={this.onBoundsChanged}
center={{ lat: 21.493468, lng: -3.177552}}
defaultCenter={this.props.center}>
</GoogleMap>
)
}
}
export default withScriptjs(withGoogleMap(Map))
The code for the component that re-renders to infinity is above, it doesn't bug out so as long as I don't setState in the onBoundsChanged function. Is there any way around this?
I am using react-google-maps.
if you want to update the marker on new position while dragging the map, you can use onBoundsChanged props
<GoogleMap
ref={refMap}
defaultZoom={13}
defaultCenter={{ lat: center.lat, lng: center.lng }}
onBoundsChanged={handleBoundsChanged}
fullscreenControl={false}
defaultOptions={defaultMapOptions}
onDragEnd={handleDragend}
>
<Marker position={center} />
</GoogleMap>
and in your handleBoundsChanged, you can update the center with new lat/lng
const handleBoundsChanged = () => {
console.log("handleBoundsChanged")
const lat = refMap.current.getCenter().lat()
const lng = refMap.current.getCenter().lng()
const mapCenter = {
lat: lat,
lng: lng,
}
setCenter(mapCenter); // move the marker to new location
};
if you want to move the map to new lat/lng programatically, you can use panTo function in useEffect when the address is updated. This is needed when you input the address in search and you want your map and marker at new location
//on address update
useEffect(() =>{
console.log("props updates", props.address, props.locationName)
if(props.address.source == 'searchbar'){
console.log("in the searchbar props")
const mapCenter = {
lat: props.address.latitude,
lng: props.address.longitude,
}
refMap.current.panTo(mapCenter) //move the map to new location
setCenter(mapCenter) // move the marker to new location
}
},[props.address])
I converted the class above from the docs compose examples, I must have screwed up somewhere because my mistake was very obvious, since on render the center is set for the GoogleMap object, all I had to do was have an initial state with a location, set the default state and then remove the 'center' prop from the component, this means that on re-render it does not pull it back to the center, and therefore does not re-trigger onBoundsChanged

Using Google Map API inside a React component

I am struggling over the way to use Google Map API inside a React component. I did not want to use popular react-google-maps nor google-map-react packages, but rather create my own.
I managed to load the script tag with the Google Map API from the React component. However, how do I manipulate the Google API from here? For example, initializing the map with even basic configuration like below?
map = new google.maps.Map(document.getElementById('map'), {
center: {lat: -34.397, lng: 150.644},
zoom: 8
});
Here is my component. Any advice is appreciated! thanks!
import React, { Component } from 'react';
// Load Google API in script tag and append
function loadScript(src) {
return new Promise((resolve, reject) => {
let script = document.createElement('script');
script.src = src;
script.addEventListener('load', function() {
resolve();
});
script.addEventListener('error', function(e) {
reject(e);
});
document.body.appendChild(script);
});
}
const script = 'https://maps.googleapis.com/maps/api/js?key=MY_API_KEY';
class MyGoogleMap extends Component {
constructor(props) {
super(props);
this.state = {};
}
componentDidMount() {
// first load the script into html
loadScript(script).then(function() {
console.log('SUCCESS');
// Where do I go from here?
});
}
render() {
return <div />;
}
}
export default MyGoogleMap;
I actually found my own solution, so I am sharing for anyone who would meet the same problem.
The basic logic is to use window object to access google.
So, after I load the script as I did from the question, I initialize my map as:
initMap = () => {
// 'google' could be accessed from 'window' object
const map = new window.google.maps.Map(
document.getElementById('googleMap'),
{
zoom: 14,
center: { lat: LATITUDE, lng: LONGTITUDE }
}
);
// putting a marker on it
const marker = new window.google.maps.Marker({
position: { lat: LATITUDE, lng: LONGTITUDE },
map: map
});
};
render() {
return (
<div id="googleMap" style={width: WIDTH, height: HEIGHT}/>
);
}
Any comment is welcomed :)
Create GoogleMap component with ref, to display google map inside that div.
import React, { Component } from 'react';
class GoogleMap extends Component {
componentDidMount() {
new google.maps.Map(this.refs.map, {
zoom: 12,
center: {
lat: this.props.lat,
lng: this.props.lon
}
});
}
render() {
return <div className="google-map" ref="map" />
}
}
export default GoogleMap;
Use it in Component you like like this:
<GoogleMap lat={lat} lon={lon}/>
by passing latitude and longitude of a city. To be able to see it you need to set width and height of css class google-map (or whatever you name it). for example:
div.google-map {
height: 150px;
width: 250px;
}
Fiddle.js preview
EDIT
inside head load script:
<script src="https://maps.googleapis.com/maps/api/js"></script>
I tought you have done that, because in your code you also use new google.maps.... If you cant call it like just google, try new window.google.maps...

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