Implementing GetFeatureInfo for WMS

src/ol/source/singleimagewmssource.js

@@ -1,8 +1,11 @@
 goog.provide('ol.source.SingleImageWMS');
 
+goog.require('goog.asserts');
+goog.require('goog.uri.utils');
 goog.require('ol.Image');
 goog.require('ol.ImageUrlFunction');
 goog.require('ol.extent');
+goog.require('ol.source.FeatureInfoSource');
 goog.require('ol.source.ImageSource');
 goog.require('ol.source.wms');
 
@@ -11,6 +14,7 @@ goog.require('ol.source.wms');
 /**
  * @constructor
  * @extends {ol.source.ImageSource}
+ * @implements {ol.source.FeatureInfoSource}
  * @param {ol.source.SingleImageWMSOptions} options Options.
  */
 ol.source.SingleImageWMS = function(options) {
@@ -28,6 +32,13 @@ ol.source.SingleImageWMS = function(options) {
     imageUrlFunction: imageUrlFunction
   });
 
+  /**
+   * @private
+   * @type {ol.source.WMSGetFeatureInfoOptions}
+   */
+  this.getFeatureInfoOptions_ = goog.isDef(options.getFeatureInfoOptions) ?
+      options.getFeatureInfoOptions : {};
+
   /**
    * @private
    * @type {ol.Image}
@@ -68,3 +79,30 @@ ol.source.SingleImageWMS.prototype.getImage =
   this.image_ = this.createImage(extent, resolution, size, projection);
   return this.image_;
 };
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.SingleImageWMS.prototype.getFeatureInfoForPixel =
+    function(pixel, map, success, opt_error) {
+  var view2D = map.getView().getView2D(),
+      projection = view2D.getProjection(),
+      size = map.getSize(),
+      bottomLeft = map.getCoordinateFromPixel([0, size[1]]),
+      topRight = map.getCoordinateFromPixel([size[0], 0]),
+      extent = [bottomLeft[0], topRight[0], bottomLeft[1], topRight[1]],
+      x = pixel[0],
+      y = pixel[1],
+      url = this.imageUrlFunction(extent, size, projection);
+  goog.asserts.assert(goog.isDef(url),
+      'ol.source.SingleImageWMS#imageUrlFunction does not return a url');
+  // TODO: X, Y is for WMS 1.1 and I, J for 1.3 - without a closure url
+  // function this could be set conditionally.
+  url = goog.uri.utils.appendParamsFromMap(url, {
+    'X': x, 'I': x,
+    'Y': y, 'J': y
+  });
+  ol.source.wms.getFeatureInfo(url, this.getFeatureInfoOptions_, success,
+      opt_error);
+};