fix copy bug

src/Address.js

@@ -1,4 +1,5 @@
-var ExtensibleData = require('./ExtensibleData');
+var ExtensibleData = require('./ExtensibleData'),
+    utils = require('./utils');
 
 /**
  * An address.
@@ -13,6 +14,11 @@ var Address = function(json){
     return new Address(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(Address.isInstance(json)){
+    return json;
+  }
+
   ExtensibleData.call(this, json);
 
   if(json){
@@ -32,6 +38,18 @@ var Address = function(json){
 
 Address.prototype = Object.create(ExtensibleData.prototype);
 
+Address._gedxClass = Address.prototype._gedxClass = 'GedcomX.Address';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+Address.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the complete address value
  * 

src/Agent.js

@@ -3,7 +3,8 @@ var ExtensibleData = require('./ExtensibleData'),
     OnlineAccount = require('./OnlineAccount'),
     Address = require('./Address'),
     Identifiers = require('./Identifiers'),
-    TextValue = require('./TextValue');
+    TextValue = require('./TextValue'),
+    utils = require('./utils');
 
 /**
  * Someone or something that curates genealogical data, such as a genealogical 
@@ -19,6 +20,11 @@ var Agent = function(json){
     return new Agent(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(Agent.isInstance(json)){
+    return json;
+  }
+
   ExtensibleData.call(this, json);
 
   if(json){
@@ -36,6 +42,18 @@ var Agent = function(json){
 
 Agent.prototype = Object.create(ExtensibleData.prototype);
 
+Agent._gedxClass = Agent.prototype._gedxClass = 'GedcomX.Agent';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+Agent.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the identifiers
  * 

src/Attribution.js

@@ -1,5 +1,6 @@
 var ExtensibleData = require('./ExtensibleData'),
-    ResourceReference = require('./ResourceReference');
+    ResourceReference = require('./ResourceReference'),
+    utils = require('./utils');
 
 /**
  * Define who is contributing information, when they contributed it, 
@@ -15,6 +16,11 @@ var Attribution = function(json){
     return new Attribution(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(Attribution.isInstance(json)){
+    return json;
+  }
+
   ExtensibleData.call(this, json);
 
   if(json){
@@ -28,6 +34,18 @@ var Attribution = function(json){
 
 Attribution.prototype = Object.create(ExtensibleData.prototype);
 
+Attribution._gedxClass = Attribution.prototype._gedxClass = 'GedcomX.Attribution';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+Attribution.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the change message.
  * 

src/Conclusion.js

@@ -2,7 +2,8 @@ var ExtensibleData = require('./ExtensibleData'),
     Attribution = require('./Attribution'),
     ResourceReference = require('./ResourceReference'),
     Note = require('./Note'),
-    SourceReference = require('./SourceReference');
+    SourceReference = require('./SourceReference'),
+    utils = require('./utils');
 
 /**
  * An abstract concept for a basic genealogical data item.
@@ -17,6 +18,11 @@ var Conclusion = function(json){
     return new Conclusion(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(Conclusion.isInstance(json)){
+    return json;
+  }
+
   ExtensibleData.call(this, json);
 
   if(json){
@@ -31,6 +37,18 @@ var Conclusion = function(json){
 
 Conclusion.prototype = Object.create(ExtensibleData.prototype);
 
+Conclusion._gedxClass = Conclusion.prototype._gedxClass = 'GedcomX.Conclusion';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+Conclusion.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the attribution.
  * 

src/Coverage.js

@@ -1,6 +1,7 @@
 var ExtensibleData = require('./ExtensibleData'),
     GDate = require('./Date'),
-    PlaceReference = require('./PlaceReference');
+    PlaceReference = require('./PlaceReference'),
+    utils = require('./utils');
 
 /**
  * A description of the spatial and temporal coverage of a resource.
@@ -15,6 +16,11 @@ var Coverage = function(json){
     return new Coverage(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(Coverage.isInstance(json)){
+    return json;
+  }
+
   ExtensibleData.call(this, json);
 
   if(json){
@@ -25,6 +31,18 @@ var Coverage = function(json){
 
 Coverage.prototype = Object.create(ExtensibleData.prototype);
 
+Coverage._gedxClass = Coverage.prototype._gedxClass = 'GedcomX.Coverage';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+Coverage.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the spatial coverage
  * 

src/Date.js

@@ -1,4 +1,5 @@
-var ExtensibleData = require('./ExtensibleData');
+var ExtensibleData = require('./ExtensibleData'),
+    utils = require('./utils');
 
 /**
  * A date.
@@ -14,6 +15,11 @@ var GDate = function(json){
     return new GDate(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(GDate.isInstance(json)){
+    return json;
+  }
+
   ExtensibleData.call(this, json);
 
   if(json){
@@ -24,6 +30,18 @@ var GDate = function(json){
 
 GDate.prototype = Object.create(ExtensibleData.prototype);
 
+GDate._gedxClass = GDate.prototype._gedxClass = 'GedcomX.Date';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+GDate.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the original date value
  * 

src/Document.js

@@ -1,5 +1,6 @@
 var Conclusion = require('./Conclusion'),
-    Attribution = require('./Attribution');
+    Attribution = require('./Attribution'),
+    utils = require('./utils');
 
 /**
  * A textual document
@@ -14,6 +15,11 @@ var Document = function(json){
     return new Document(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(Document.isInstance(json)){
+    return json;
+  }
+
   Conclusion.call(this, json);
 
   if(json){
@@ -27,6 +33,18 @@ var Document = function(json){
 
 Document.prototype = Object.create(Conclusion.prototype);
 
+Document._gedxClass = Document.prototype._gedxClass = 'GedcomX.Document';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+Document.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the type
  * 

src/Event.js

@@ -1,7 +1,8 @@
 var Subject = require('./Subject'),
     GDate = require('./Date'),
     PlaceReference = require('./PlaceReference'),
-    EventRole = require('./EventRole');
+    EventRole = require('./EventRole'),
+    utils = require('./utils');
 
 /**
  * An event.
@@ -16,6 +17,11 @@ var Event = function(json){
     return new Event(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(Event.isInstance(json)){
+    return json;
+  }
+
   Subject.call(this, json);
 
   if(json){
@@ -28,6 +34,18 @@ var Event = function(json){
 
 Event.prototype = Object.create(Subject.prototype);
 
+Event._gedxClass = Event.prototype._gedxClass = 'GedcomX.Event';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+Event.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the type
  * 

src/EventRole.js

@@ -1,5 +1,6 @@
 var Conclusion = require('./Conclusion'),
-    ResourceReference = require('./ResourceReference');
+    ResourceReference = require('./ResourceReference'),
+    utils = require('./utils');
 
 /**
  * A role that a specific person plays in an event.
@@ -14,6 +15,11 @@ var EventRole = function(json){
     return new EventRole(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(Conclusion.isInstance(json)){
+    return json;
+  }
+
   Conclusion.call(this, json);
 
   if(json){
@@ -25,6 +31,18 @@ var EventRole = function(json){
 
 EventRole.prototype = Object.create(Conclusion.prototype);
 
+Conclusion._gedxClass = Conclusion.prototype._gedxClass = 'GedcomX.Conclusion';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+Conclusion.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the person
  * 

src/EvidenceReference.js

@@ -1,5 +1,6 @@
 var ResourceReference = require('./ResourceReference'),
-    Attribution = require('./Attribution');
+    Attribution = require('./Attribution'),
+    utils = require('./utils');
 
 /**
  * A generic reference to a resource.
@@ -14,6 +15,11 @@ var EvidenceReference = function(json){
     return new EvidenceReference(json);
   }
 
+  // If the given object is already an instance then just return it. DON'T copy it.
+  if(ResourceReference.isInstance(json)){
+    return json;
+  }
+
   ResourceReference.call(this, json);
 
   if(json){
@@ -23,6 +29,18 @@ var EvidenceReference = function(json){
 
 EvidenceReference.prototype = Object.create(ResourceReference.prototype);
 
+ResourceReference._gedxClass = ResourceReference.prototype._gedxClass = 'GedcomX.ResourceReference';
+
+/**
+ * Check whether the given object is an instance of this class.
+ * 
+ * @param {Object} obj
+ * @returns {Boolean}
+ */
+ResourceReference.isInstance = function(obj){
+  return utils.isInstance(obj, this._gedxClass);
+};
+
 /**
  * Get the attribution.
  *