leaflet

What is leaflet?

Leaflet is a widely used open-source JavaScript library that helps you create mobile-friendly interactive maps. It provides features that allow users to embed maps into web pages, add various types of layers, markers, popups, and handle user interactions with the map.

What are leaflet's main functionalities?

Map Initialization

This code initializes a new map in the 'mapid' HTML element and sets the view to a specific latitude and longitude and a zoom level.

var map = L.map('mapid').setView([51.505, -0.09], 13);

Tile Layer

This code adds a tile layer to the map using OpenStreetMap tiles. It sets the maximum zoom level and adds attribution text.

L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
  maxZoom: 19,
  attribution: '© OpenStreetMap contributors'
}).addTo(map);

Markers

This code places a marker on the map at the specified latitude and longitude.

var marker = L.marker([51.5, -0.09]).addTo(map);

Popups

This code binds a popup with some HTML content to the previously created marker and opens it.

marker.bindPopup('<b>Hello world!</b><br>I am a popup.').openPopup();

GeoJSON

This code adds a GeoJSON layer to the map. The 'geojsonData' variable should contain valid GeoJSON.

L.geoJSON(geojsonData).addTo(map);

Other packages similar to leaflet

openlayers

OpenLayers is an open-source JavaScript library for displaying map data in web browsers. It provides a similar range of features to Leaflet, but it is known for being more feature-rich and customizable, which can make it more complex to use.

mapbox-gl

Mapbox GL JS is a JavaScript library that uses WebGL to render interactive maps from vector tiles and Mapbox styles. It is known for its smooth rendering capabilities and is suitable for applications that require more advanced visual effects and functionalities.

google-maps-react

This package is a wrapper around the Google Maps API for use within React applications. It allows for the integration of Google Maps features, but it requires an API key and is not open-source like Leaflet.

README

Leaflet is the leading open-source JavaScript library for mobile-friendly interactive maps. Weighing just about 37 KB of gzipped JS code, it has all the mapping features most developers ever need.

Leaflet is designed with simplicity, performance and usability in mind. It works efficiently across all major desktop and mobile platforms out of the box, taking advantage of HTML5 and CSS3 on modern browsers while being accessible on older ones too. It can be extended with a huge amount of plugins, has a beautiful, easy to use and well-documented API and a simple, readable source code that is a joy to contribute to.

For more info, docs and tutorials, check out the official website.
For Leaflet downloads (including the built master version), check out the download page.

We're happy to meet new contributors. If you want to get involved with Leaflet development, check out the contribution guide. Let's make the best mapping library that will ever exist, and push the limits of what's possible with online maps!

Changelog

1.0.2 (2016-11-21)

Bug fixes

• Fix CSS for marker shadows when max-width is already set (by @brunob, #5046).
• Fix canvas redraw when style updates fill and/or weight (by @perliedman, #5034).
• Prevent canvas from firing multiple mouseover events for same layer (by @perliedman, #5033).
• Fixed a race condition when removing and adding L.Canvas vectors during a zoom animation (by @ghybs) #5011.
• Fix zoom animation of ImageOverlay when CRS's Y axis is flipped (by @perliedman), #4993.
• Fix encoding/decoding of GeoJSON FeatureCollections (by @IvanSanchez), #5045.
• Fix minZoom/maxZoom late inizialization (by @IvanSanchez), #4916.
• Fix styling of custom SVG markers by making stricter CSS selectors (by @jwoyame) #4597.
• Fix order of mouseover/mouseout events on overlapping L.Canvas layers (by @perliedman), #5090.
• Fix drag behaviour when a draggable marker is removed in mid-drag (by @IvanSanchez, #5063.
• Fix L.Control.Layers.collapse() on initially uncollapsed layer controls (by @perliedman), #5131.
• Fix blurriness of L.Tooltip by rounding up pixel coordinates (by @ashmigelski), #5089.
• Fix click events on overlapping geometries when using L.Canvas (by @perliedman), #5100.

API changes

• Add a sortLayers option to L.Control.Layers (by @IvanSanchez, #4711.
• Implement bringToFront and bringToBack when using L.Canvas, plus preventing other canvas glitches (by @perliedman), #5115.
• Add minNativeZoom option to L.TileLayers. (by @bb-juliogarcia), #5088.

Improvements

• Improve performance when adding lots of L.Paths by refactoring away event logic (by @IvanSanchez) #5054)].
• Several minor documentation improvements by @Jmuccigr, @serdarkacka, @erickzhao, @IvanSanchez, @perliedman, @joukewitteveen.
• Code reorganization: Extensions for L.Marker and L.Map no longer have a separate file (by @mourner).
• Removed a duplicated unit test (@yohanboniface).
• Accesibility improvements (ARIA/screenreader related) on map tiles (by @patrickarlt) #5092.