## leaflet-image

Export images out of Leaflet maps without a server component, by using Canvas and CORS.

## Requirements

- Tile layer providers (OSM, MapBox, etc) must support CORS
- Any markers on the map must also support CORS. The default Leaflet-CDN markers don't, so they aren't supported.
- Your browser must support CORS and Canvas, so `IE >= 10` with no exceptions.
- This library does not rasterize HTML because browsers cannot rasterize HTML. Therefore, L.divIcon and other HTML-based features of a map, like zoom controls or legends, are not included in the output, because they are HTML.

For Leaflet < 1.0.0: You must set `L_PREFER_CANVAS = true;` so that vector layers are drawn in Canvas

For Leaflet >= 1.0.0: You must set `renderer: L.canvas()` for any layer that you want included in the generated image. You can also set this by setting `preferCanvas: true` in your map's options.

## Plugins that will not work with leaflet-image

- Leaflet.label: will not work because it uses HTML to display labels.
- Leaflet.markercluster: will not work because it uses HTML for clusters.

### Usage

browserify

    npm install --save leaflet-image

web

    curl https://raw.github.com/mapbox/leaflet-image/gh-pages/leaflet-image.js > leaflet-image.js

### Example

    var map = L.mapbox.map('map', 'YOUR.MAPID').setView([38.9, -77.03], 14);
    leafletImage(map, function(err, canvas) {
        // now you have canvas
        // example thing to do with that canvas:
        var img = document.createElement('img');
        var dimensions = map.getSize();
        img.width = dimensions.x;
        img.height = dimensions.y;
        img.src = canvas.toDataURL();
        document.getElementById('images').innerHTML = '';
        document.getElementById('images').appendChild(img);
    });

### Plugin CDN

leaflet-image is available through the Mapbox Plugin CDN so you don't need to download & copy it. Just include the following script tag:

    <script src='//api.tiles.mapbox.com/mapbox.js/plugins/leaflet-image/v0.0.4/leaflet-image.js'></script>

### API

    leafletImage(map, callback)

map is a `L.map` or `L.mapbox.map`, callback takes `(err, canvas)`.

## Attribution

Any images you generate from maps that require attribution - which is most, including all from commercial sources and those that include any data from OpenStreetMap - will require the same attribution as the map did. Remember to attribute.

## See Also

- The Mapbox Static Image API is simpler to use and faster than this approach.