Handle not-ready layers in attribution view

src/ol/view/attribution.js

@@ -1,7 +1,6 @@
 // FIXME handle rotation
 // FIXME probably need to abstract out a "layers listener"
 // FIXME handle layer order
-// FIXME handle not-ready layers
 
 goog.provide('ol.view.Attribution');
 
@@ -76,21 +75,12 @@ ol.view.Attribution = function(map) {
 goog.inherits(ol.view.Attribution, ol.View);
 
 
-/**
- * @inheritDoc
- */
-ol.view.Attribution.prototype.getElement = function() {
-  return this.ulElement_;
-};
-
-
 /**
  * @param {ol.Layer} layer Layer.
- * @protected
+ * @private
  */
-ol.view.Attribution.prototype.handleLayerAdd = function(layer) {
-
-  var layerKey = goog.getUid(layer);
+ol.view.Attribution.prototype.createAttributionElementsForLayer_ =
+    function(layer) {
 
   var map = this.getMap();
   var mapIsDef = map.isDef();
@@ -100,11 +90,11 @@ ol.view.Attribution.prototype.handleLayerAdd = function(layer) {
 
   var layerVisible = layer.getVisible();
 
-  this.layerVisibleChangeListenerKeys_[layerKey] = goog.events.listen(
-      layer, ol.Object.getChangedEventType(ol.LayerProperty.VISIBLE),
-      this.handleLayerVisibleChanged, false, this);
+  var store = layer.getStore();
+  var attributions = store.getAttributions();
+  if (!goog.isNull(attributions)) {
 
-  goog.array.forEach(layer.getStore().getAttributions(), function(attribution) {
+    goog.array.forEach(attributions, function(attribution) {
 
       var attributionKey = goog.getUid(attribution);
 
@@ -122,6 +112,47 @@ ol.view.Attribution.prototype.handleLayerAdd = function(layer) {
 
     }, this);
 
+  }
+
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.view.Attribution.prototype.getElement = function() {
+  return this.ulElement_;
+};
+
+
+/**
+ * @param {ol.Layer} layer Layer.
+ * @protected
+ */
+ol.view.Attribution.prototype.handleLayerAdd = function(layer) {
+
+  var layerKey = goog.getUid(layer);
+
+  this.layerVisibleChangeListenerKeys_[layerKey] = goog.events.listen(
+      layer, ol.Object.getChangedEventType(ol.LayerProperty.VISIBLE),
+      this.handleLayerVisibleChanged, false, this);
+
+  if (layer.getStore().isReady()) {
+    this.createAttributionElementsForLayer_(layer);
+  } else {
+    goog.events.listenOnce(layer, goog.events.EventType.LOAD,
+        this.handleLayerLoad, false, this);
+  }
+
+};
+
+
+/**
+ * @param {goog.events.Event} event Event.
+ */
+ol.view.Attribution.prototype.handleLayerLoad = function(event) {
+  var layer = /** @type {ol.Layer} */ event.target;
+  this.createAttributionElementsForLayer_(layer);
 };