add clone() method to Layer class, add test.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@879 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer.js

@@ -75,6 +75,30 @@ OpenLayers.Layer.prototype = {
         }
         this.map = null;
     },
+    
+   /**
+    * @param {String} newName
+    * @param {Hash} newOptions
+    *
+    * @returns A clone of this OpenLayers.Layer
+    * @type OpenLayers.Layer
+    */
+    clone: function (newName, newOptions) {
+
+        if (newName == null) {
+            newName = this.name;
+        }
+
+        var mergedOptions = null;
+        if ( (this.options != null) || (newOptions != null) ) {
+            // only merge options if there were or will be
+            mergedOptions = Object.extend( {}, this.options);
+            Object.extend(mergedOptions, newOptions);
+        }
+            
+        return new OpenLayers.Layer(newName, mergedOptions);
+    },
+    
 
     /**
     * @params {OpenLayers.Bounds} bound

tests/test_Layer.html

@@ -12,6 +12,50 @@
         t.eq( layer.name, "Test Layer", "layer.name is correct" );
     }
 
+    function test_02_Layer_clone (t) {
+        t.plan( 7 );
+        
+        var options = { chicken: 151, foo: "bar" };
+        var layer = new OpenLayers.Layer('Test Layer', options);
+        var clone = layer.clone();
+        
+        t.ok( clone instanceof OpenLayers.Layer, "new OpenLayers.Layer returns object" );
+        t.eq( clone.name, "Test Layer", "default clone.name is correct" );
+        t.ok( ((clone.options["chicken"] == 151) && (clone.options["foo"] == "bar")), "clone.options correctly set" );
+
+
+        var layer = new OpenLayers.Layer('Test Layer');
+        var clone = layer.clone();
+        
+        t.ok( clone.options == null, "clone.options correctly left at null" );
+
+
+
+        var layer = new OpenLayers.Layer('Test Layer', options);
+        var clone = layer.clone("Special Bonus");
+        
+        t.eq( clone.name, "Special Bonus", "clone.name is correct" );
+
+
+
+        var newOptions = { foo: "stoo", clear: "skies" };
+        var layer = new OpenLayers.Layer('Test Layer', options);
+        var clone = layer.clone("Special Bonus", newOptions);
+        
+        t.ok( ((clone.options["chicken"] == 151) && 
+               (clone.options["foo"] == "stoo") &&
+               (clone.options["clear"] == "skies")), "clone.options correctly merged" );
+
+
+        var newOptions = { chicken: 151, foo: "stoo", clear: "skies" };
+        var layer = new OpenLayers.Layer('Test Layer');
+        var clone = layer.clone("Special Bonus", newOptions);
+
+        t.ok( ((clone.options["foo"] == "stoo") &&
+               (clone.options["clear"] == "skies")), "clone.options correctly merged" );
+
+    }
+
     function test_99_Layer_destroy (t) {
         t.plan( 1 );    
         layer = new OpenLayers.Layer('Test Layer');