mapbox-gl-compare

Swipe and sync between two maps

Map movements are synced with mapbox-gl-sync-move.

Installation

CDN

Include the script and stylesheet in your HTML. Compare is available globally as mapboxgl.Compare.

<script src="https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-compare/v0.5.0/mapbox-gl-compare.js"></script>
<link rel="stylesheet" href="https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-compare/v0.5.0/mapbox-gl-compare.css">

ESM via npm

npm install mapbox-gl-compare

import Compare from 'mapbox-gl-compare';
import 'mapbox-gl-compare/dist/mapbox-gl-compare.css';

Usage

CDN

var before = new mapboxgl.Map({
  container: 'before',
  style: 'mapbox://styles/mapbox/light-v11'
});

var after = new mapboxgl.Map({
  container: 'after',
  style: 'mapbox://styles/mapbox/dark-v11'
});

// A selector or reference to HTML element
var container = '#comparison-container';

new mapboxgl.Compare(before, after, container, {
  mousemove: true, // Optional. Set to true to enable swiping during cursor movement.
  orientation: 'vertical' // Optional. Sets the orientation of swiper to horizontal or vertical, defaults to vertical
});

ESM

import * as mapboxgl from 'mapbox-gl';
import Compare from 'mapbox-gl-compare';
import 'mapbox-gl-compare/dist/mapbox-gl-compare.css';

const before = new mapboxgl.Map({
  container: 'before',
  style: 'mapbox://styles/mapbox/light-v11'
});

const after = new mapboxgl.Map({
  container: 'after',
  style: 'mapbox://styles/mapbox/dark-v11'
});

// A selector or reference to HTML element
const container = '#comparison-container';

new Compare(before, after, container, {
  mousemove: true, // Optional. Set to true to enable swiping during cursor movement.
  orientation: 'vertical' // Optional. Sets the orientation of swiper to horizontal or vertical, defaults to vertical
});

Methods

compare = new mapboxgl.Compare(before, after, container, {
  mousemove: true, // Optional. Set to true to enable swiping during cursor movement.
  orientation: 'vertical' // Optional. Sets the orientation of swiper to horizontal or vertical, defaults to vertical
});

//Get Current position - this will return the slider's current position, in pixels
compare.currentPosition;

//Set Position - this will set the slider at the specified (x) number of pixels from the left-edge or top-edge of viewport based on swiper orientation
compare.setSlider(x);

//Listen to slider movement - and return current position on each slideend
compare.on('slideend', (e) => {
  console.log(e.currentPosition);
});

//Remove - this will remove the compare control from the DOM and stop synchronizing the two maps.
compare.remove();

Demo: https://www.mapbox.com/mapbox-gl-js/example/mapbox-gl-compare/

See API.md for complete reference.

Developing

Create a .env file at the repo root with your Mapbox access token:

VITE_MAPBOX_ACCESS_TOKEN=your_token_here

Then start the dev server:

npm start

Testing

Tests run in a real browser via Vitest and Playwright. Install the Playwright browser before running tests for the first time:

npx playwright install chromium

A Mapbox access token is also required — see Developing for .env setup. Then run:

npm test

Deploying

npm registry

• Update the version key in package.json
• Update CHANGELOG.md
• Commit and push
• git tag -a vX.X.X -m 'vX.X.X'
• git push --tags
• npm publish
• Update version number in GL JS docs

mapbox cdn

• aws s3 cp --acl public-read ./dist/mapbox-gl-compare.js s3://mapbox-gl-js/plugins/mapbox-gl-compare/v$(node --print --eval "require('./package.json').version")/mapbox-gl-compare.js
• aws s3 cp --acl public-read ./dist/mapbox-gl-compare.css s3://mapbox-gl-js/plugins/mapbox-gl-compare/v$(node --print --eval "require('./package.json').version")/mapbox-gl-compare.css