Give ol.Image an imageLoadFunction argument

src/ol/imageloadfunction.js

@@ -0,0 +1,21 @@
+goog.provide('ol.ImageLoadFunctionType');
+
+
+/**
+ * A function that takes an {@link ol.Image} for the image and a `{string}` for
+ * the src as arguments. It is supposed to make it so the underlying image
+ * {@link ol.Image#getImage} is assigned the content specified by the src. If
+ * not specified, the default is
+ *
+ *     function(image, src) {
+ *       image.getImage().src = src;
+ *     }
+ *
+ * Providing a custom `imageLoadFunction` can be useful to load images with
+ * post requests or - in general - through XHR requests, where the src of the
+ * image element would be set to a data URI when the content is loaded.
+ *
+ * @typedef {function(ol.Image, string)}
+ * @api
+ */
+ol.ImageLoadFunctionType;