contao-leaflet-libraries/assets/leaflet-providers/README.md

Leaflet-providers
=================
An extension to [Leaflet](http://leafletjs.com/) that contains configurations for various free<sup>[1](#what-is-free)</sup> tile providers.

# Usage
Leaflet-providers [providers](#providers) are refered to with a `provider[.<variant>]`-string. Let's say you want to add the nice [Watercolor](http://maps.stamen.com/#watercolor/) style from Stamen to your map, you pass `Stamen.Watercolor` to the `L.tileLayer.provider`-constructor, which will return a [L.TileLayer](http://leafletjs.com/reference.html#tilelayer) instance for Stamens Watercolor tile layer.

```Javascript
// add Stamen Watercolor to map.
L.tileLayer.provider('Stamen.Watercolor').addTo(map);
```

## Protocol relativity (`https://`-urls)

Leaflet-providers tries to use `https://` if the page uses `https://` and the provider supports it.
You can force the use of `http://` by passing `force_http: true` in the options argument.

## Retina tiles

Some providers have retina tiles for which the URL only needs to be slightly adjusted, e.g. `-----@2x.png`. For this, add the retina option in the URL, e.g. `-----{retina}.png`, and set a retina value in the options, e.g. `retina: '@2x'`. If Leaflet detects a retina screen (`L.Browser.retina`), the retina option passed to the tileLayer is set to the value supplied, otherwise it's replaced by an empty string.

# Providers

Leaflet-providers provides tile layers from different providers, including *OpenStreetMap*, *Stamen*, *Esri* and *OpenWeatherMap*. The full listing of free to use layers can be [previewed](http://leaflet-extras.github.io/leaflet-providers/preview/index.html). The page will show you the name to use with `leaflet-providers.js` and the code to use it without dependencies.

## Providers requiring registration

In addition to the providers you are free<b id="what-is-free">1</b> to use, we support some layers which require registration.

### HERE (formerly Nokia).

In order to use HERE layers, you must [register](http://developer.here.com/). Once registered, you can create an `app_id` and `app_code` which you have to pass to `L.tileLayer.provider` in the options:

```Javascript
L.tileLayer.provider('HERE.terrainDay', {
    app_id: '<insert ID here>',
    app_code: '<insert ID here>'
}).addTo(map);
```

[Available HERE layers](http://leaflet-extras.github.io/leaflet-providers/preview/#filter=HERE)

### Mapbox

In order to use Mapbox maps, you must [register](https://tiles.mapbox.com/signup). You can get map ID and ACCESS_TOKEN from [Mapbox projects](https://www.mapbox.com/projects):
```JavaScript
L.tileLayer.provider('MapBox', {id: 'ID', accessToken: 'ACCESS_TOKEN'}).addTo(map);
```

### Esri/ArcGIS

In order to use ArcGIS maps, you must [register](https://developers.arcgis.com/en/sign-up/) and abide by the [terms of service](https://developers.arcgis.com/en/terms/). No special syntax is required.

[Available Esri layers](http://leaflet-extras.github.io/leaflet-providers/preview/#filter=Esri)

# Attribution

This work was inspired from <https://gist.github.com/1804938>, and originally created by [Stefan Seelmann](https://github.com/seelmann).

### What do we mean by *free*?
<b id="what-is-free">1</b>
We try to maintain leaflet-providers in such a way that you'll be able to use the layers we include without paying money.
This doesn't mean no limits apply, you should always check before using these layers for anything serious.