Control.Attribution.js

import {Control} from './Control';
import {Map} from '../map/Map';
import * as Util from '../core/Util';
import * as DomEvent from '../dom/DomEvent';
import * as DomUtil from '../dom/DomUtil';

/*
 * @class Control.Attribution
 * @aka L.Control.Attribution
 * @inherits Control
 *
 * The attribution control allows you to display attribution data in a small text box on a map. It is put on the map by default unless you set its [`attributionControl` option](#map-attributioncontrol) to `false`, and it fetches attribution texts from layers with the [`getAttribution` method](#layer-getattribution) automatically. Extends Control.
 */

export var Attribution = Control.extend({
	// @section
	// @aka Control.Attribution options
	options: {
		position: 'bottomright',

		// @option prefix: String = 'Leaflet'
		// The HTML text shown before the attributions. Pass `false` to disable.
		prefix: '<a href="https://leafletjs.com" title="A JS library for interactive maps">Leaflet</a>'
	},

	initialize: function (options) {
		Util.setOptions(this, options);

		this._attributions = {};
	},

	onAdd: function (map) {
		map.attributionControl = this;
		this._container = DomUtil.create('div', 'leaflet-control-attribution');
		DomEvent.disableClickPropagation(this._container);

		// TODO ugly, refactor
		for (var i in map._layers) {
			if (map._layers[i].getAttribution) {
				this.addAttribution(map._layers[i].getAttribution());
			}
		}

		this._update();

		return this._container;
	},

	// @method setPrefix(prefix: String): this
	// Sets the text before the attributions.
	setPrefix: function (prefix) {
		this.options.prefix = prefix;
		this._update();
		return this;
	},

	// @method addAttribution(text: String): this
	// Adds an attribution text (e.g. `'Vector data &copy; Mapbox'`).
	addAttribution: function (text) {
		if (!text) { return this; }

		if (!this._attributions[text]) {
			this._attributions[text] = 0;
		}
		this._attributions[text]++;

		this._update();

		return this;
	},

	// @method removeAttribution(text: String): this
	// Removes an attribution text.
	removeAttribution: function (text) {
		if (!text) { return this; }

		if (this._attributions[text]) {
			this._attributions[text]--;
			this._update();
		}

		return this;
	},

	_update: function () {
		if (!this._map) { return; }

		var attribs = [];

		for (var i in this._attributions) {
			if (this._attributions[i]) {
				attribs.push(i);
			}
		}

		var prefixAndAttribs = [];

		if (this.options.prefix) {
			prefixAndAttribs.push(this.options.prefix);
		}
		if (attribs.length) {
			prefixAndAttribs.push(attribs.join(', '));
		}

		this._container.innerHTML = prefixAndAttribs.join(' | ');
	}
});

// @namespace Map
// @section Control options
// @option attributionControl: Boolean = true
// Whether a [attribution control](#control-attribution) is added to the map by default.
Map.mergeOptions({
	attributionControl: true
});

Map.addInitHook(function () {
	if (this.options.attributionControl) {
		new Attribution().addTo(this);
	}
});

// @namespace Control.Attribution
// @factory L.control.attribution(options: Control.Attribution options)
// Creates an attribution control.
export var attribution = function (options) {
	return new Attribution(options);
};