Merge pull request #4926 from aisaacs/cartodb

Add CartoDB tile source.

src/ol/source/cartodb.js

@@ -0,0 +1,132 @@
+goog.provide('ol.source.CartoDB');
+
+goog.require('ol.source.State');
+goog.require('ol.source.XYZ');
+
+
+/**
+ * @classdesc
+ * Layer source for the CartoDB tiles.
+ *
+ * @constructor
+ * @extends {ol.source.XYZ}
+ * @param {olx.source.CartoDBOptions} options CartoDB options.
+ * @api
+ */
+ol.source.CartoDB = function(options) {
+  this.account_ = options.account;
+  this.mapId_ = options.map || '';
+  this.config_ = options.config || {};
+  this.templateCache_ = {};
+  delete options.map;
+  goog.base(this, options);
+  this.initializeMap_();
+};
+goog.inherits(ol.source.CartoDB, ol.source.XYZ);
+
+
+/**
+ * Returns the current config.
+ * @return {Object} The current configuration.
+ * @api
+ */
+ol.source.CartoDB.prototype.getConfig = function() {
+  return this.config_;
+};
+
+
+/**
+ * Updates the carto db config.
+ * @param {Object} config a key-value lookup. Values will replace current values
+ *     in the config.
+ * @api
+ */
+ol.source.CartoDB.prototype.updateConfig = function(config) {
+  for (var key in config) {
+    this.config_[key] = config[key];
+  }
+  this.initializeMap_();
+};
+
+
+/**
+ * Sets the CartoDB config
+ * @param {Object} config In the case of anonymous maps, a CartoDB configuration
+ *     object.
+ * If using named maps, a key-value lookup with the template parameters.
+ */
+ol.source.CartoDB.prototype.setConfig = function(config) {
+  this.config_ = config || {};
+  this.initializeMap_();
+};
+
+
+/**
+ * Issue a request to initialize the CartoDB map.
+ * @private
+ */
+ol.source.CartoDB.prototype.initializeMap_ = function() {
+  var paramHash = JSON.stringify(this.config_);
+  if (this.templateCache_[paramHash]) {
+    this.applyTemplate_(this.templateCache_[paramHash]);
+    return;
+  }
+  var mapUrl = 'https://' + this.account_ +
+      '.cartodb.com/api/v1/map';
+
+  if (this.mapId_) {
+    mapUrl += '/named/' + this.mapId_;
+  }
+
+  var client = new XMLHttpRequest();
+  client.addEventListener('load', this.handleInitResponse_.bind(this, paramHash));
+  client.addEventListener('error', this.handleInitError_.bind(this));
+  client.open('POST', mapUrl);
+  client.setRequestHeader('Content-type', 'application/json');
+  client.send(JSON.stringify(this.config_));
+};
+
+
+/**
+ * Handle map initialization response.
+ * @param {string} paramHash a hash representing the parameter set that was used
+ *     for the request
+ * @param {Event} event Event.
+ * @private
+ */
+ol.source.CartoDB.prototype.handleInitResponse_ = function(paramHash, event) {
+  var client = /** @type {XMLHttpRequest} */ (event.target);
+  if (client.status >= 200 && client.status < 300) {
+    var response;
+    try {
+      response = /** @type {Object} */(JSON.parse(client.responseText));
+    } catch (err) {
+      this.setState(ol.source.State.ERROR);
+      return;
+    }
+    this.applyTemplate_(response);
+    this.templateCache_[paramHash] = response;
+  } else {
+    this.setState(ol.source.State.ERROR);
+  }
+};
+
+/**
+ * @private
+ * @param {Event} event Event.
+ */
+ol.source.CartoDB.prototype.handleInitError_ = function(event) {
+  this.setState(ol.source.State.ERROR);
+}
+
+/**
+ * Apply the new tile urls returned by carto db
+ * @param {Object} data Result of carto db call.
+ * @private
+ */
+ol.source.CartoDB.prototype.applyTemplate_ = function(data) {
+  var layerId = data['layergroupid'];
+  var tilesUrl = 'https://' + data['cdn_url']['https'] + '/' + this.account_ +
+      '/api/v1/map/' + layerId + '/{z}/{x}/{y}.png';
+  this.setUrl(tilesUrl);
+};