Add subclassing support

KissXML/Additions/DDXMLElementAdditions.m

@@ -2,12 +2,17 @@
 
 @implementation DDXMLElement (DDAdditions)
 
++ (Class)replacementClassForClass:(Class)currentClass {
+    return currentClass;
+}
+
 /**
  * Quick method to create an element
 **/
 + (DDXMLElement *)elementWithName:(NSString *)name xmlns:(NSString *)ns
 {
-	DDXMLElement *element = [DDXMLElement elementWithName:name];
+    Class type = [[self class] replacementClassForClass:[DDXMLElement class]];
+	DDXMLElement *element = [type elementWithName:name];
 	[element setXmlns:ns];
 	return element;
 }
@@ -83,7 +88,8 @@ - (void)setXmlns:(NSString *)ns
 	// 
 	// This applies to both Apple's NSXML and DDXML.
 
-	[self addNamespace:[DDXMLNode namespaceWithName:@"" stringValue:ns]];
+    Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+	[self addNamespace:[type namespaceWithName:@"" stringValue:ns]];
 }
 
 /**
@@ -107,7 +113,8 @@ - (NSString *)compactXMLString
 **/
 - (void)addAttributeWithName:(NSString *)name stringValue:(NSString *)string
 {
-	[self addAttribute:[DDXMLNode attributeWithName:name stringValue:string]];
+    Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+	[self addAttribute:[type attributeWithName:name stringValue:string]];
 }
 
 /**

KissXML/DDXMLDocument.m

@@ -21,13 +21,18 @@
 
 @implementation DDXMLDocument
 
++ (Class)replacementClassForClass:(Class)currentClass {
+    return currentClass;
+}
+
 /**
  * Returns a DDXML wrapper object for the given primitive node.
  * The given node MUST be non-NULL and of the proper type.
 **/
 + (id)nodeWithDocPrimitive:(xmlDocPtr)doc owner:(DDXMLNode *)owner
 {
-	return [[[DDXMLDocument alloc] initWithDocPrimitive:doc owner:owner] autorelease];
+    Class type = [[self class] replacementClassForClass:[DDXMLDocument class]];
+	return [[[type alloc] initWithDocPrimitive:doc owner:owner] autorelease];
 }
 
 - (id)initWithDocPrimitive:(xmlDocPtr)doc owner:(DDXMLNode *)inOwner
@@ -116,8 +121,10 @@ - (DDXMLElement *)rootElement
 
 	xmlNodePtr rootNode = xmlDocGetRootElement(doc);
 
-	if (rootNode != NULL)
-		return [DDXMLElement nodeWithElementPrimitive:rootNode owner:self];
+	if (rootNode != NULL){
+		Class type = [[self class] replacementClassForClass:[DDXMLElement class]];
+        return [type nodeWithElementPrimitive:rootNode owner:self];
+    }
 	else
 		return nil;
 }

KissXML/DDXMLElement.m

@@ -21,13 +21,18 @@
 
 @implementation DDXMLElement
 
++ (Class)replacementClassForClass:(Class)currentClass {
+    return currentClass;
+}
+
 /**
  * Returns a DDXML wrapper object for the given primitive node.
  * The given node MUST be non-NULL and of the proper type.
 **/
 + (id)nodeWithElementPrimitive:(xmlNodePtr)node owner:(DDXMLNode *)owner
 {
-	return [[[DDXMLElement alloc] initWithElementPrimitive:node owner:owner] autorelease];
+    Class type = [[self class] replacementClassForClass:[DDXMLElement class]];
+	return [[[type alloc] initWithElementPrimitive:node owner:owner] autorelease];
 }
 
 - (id)initWithElementPrimitive:(xmlNodePtr)node owner:(DDXMLNode *)inOwner
@@ -103,7 +108,8 @@ - (id)initWithName:(NSString *)name stringValue:(NSString *)string
 
 - (id)initWithXMLString:(NSString *)string error:(NSError **)error
 {
-	DDXMLDocument *doc = [[DDXMLDocument alloc] initWithXMLString:string options:0 error:error];
+    Class type = [[self class] replacementClassForClass:[DDXMLDocument class]];
+	DDXMLDocument *doc = [[type alloc] initWithXMLString:string options:0 error:error];
 	if (doc == nil)
 	{
 		[self release];
@@ -177,7 +183,8 @@ - (NSArray *)_elementsForName:(NSString *)name
 
 			if (match)
 			{
-				[result addObject:[DDXMLElement nodeWithElementPrimitive:child owner:self]];
+                Class type = [[self class] replacementClassForClass:[DDXMLElement class]];
+				[result addObject:[type nodeWithElementPrimitive:child owner:self]];
 			}
 		}
 
@@ -210,7 +217,8 @@ - (NSArray *)elementsForName:(NSString *)name
 	NSString *prefix;
 	NSString *localName;
 
-	[DDXMLNode getPrefix:&prefix localName:&localName forName:name];
+    Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+	[type getPrefix:&prefix localName:&localName forName:name];
 
 	if ([prefix length] > 0)
 	{
@@ -253,7 +261,8 @@ - (NSArray *)elementsForLocalName:(NSString *)localName URI:(NSString *)uri
 		NSString *prefix;
 		NSString *realLocalName;
 
-		[DDXMLNode getPrefix:&prefix localName:&realLocalName forName:localName];
+        Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+		[type getPrefix:&prefix localName:&realLocalName forName:localName];
 
 		return [self _elementsForName:localName localName:realLocalName prefix:prefix uri:uri];
 	}
@@ -297,7 +306,8 @@ - (void)_removeAttributeForName:(NSString *)name
 		{
 			if (xmlStrEqual(attr->name, xmlName))
 			{
-				[DDXMLNode removeAttribute:attr];
+                Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+				[type removeAttribute:attr];
 				return;
 			}
 			attr = attr->next;
@@ -407,8 +417,8 @@ - (void)setAttributes:(NSArray *)attributes
 #if DDXML_DEBUG_MEMORY_ISSUES
 	DDXMLNotZombieAssert();
 #endif
-
-	[DDXMLNode removeAllAttributesFromNode:(xmlNodePtr)genericPtr];
+	Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+	[type removeAllAttributesFromNode:(xmlNodePtr)genericPtr];
 
 	NSUInteger i;
 	for (i = 0; i < [attributes count]; i++)
@@ -436,7 +446,8 @@ - (void)_removeNamespaceForPrefix:(NSString *)name
 	{
 		if (xmlStrEqual(ns->prefix, xmlName))
 		{
-			[DDXMLNode removeNamespace:ns fromNode:node];
+            Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+			[type removeNamespace:ns fromNode:node];
 			break;
 		}
 		ns = ns->next;
@@ -577,7 +588,8 @@ - (void)setNamespaces:(NSArray *)namespaces
 	DDXMLNotZombieAssert();
 #endif
 
-	[DDXMLNode removeAllNamespacesFromNode:(xmlNodePtr)genericPtr];
+    Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+	[type removeAllNamespacesFromNode:(xmlNodePtr)genericPtr];
 
 	NSUInteger i;
 	for (i = 0; i < [namespaces count]; i++)
@@ -778,7 +790,8 @@ - (void)removeChildAtIndex:(NSUInteger)index
 		{
 			if (i == index)
 			{
-				[DDXMLNode removeChild:child];
+                Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+				[type removeChild:child];
 				return;
 			}
 
@@ -793,8 +806,9 @@ - (void)setChildren:(NSArray *)children
 #if DDXML_DEBUG_MEMORY_ISSUES
 	DDXMLNotZombieAssert();
 #endif
-
-	[DDXMLNode removeAllChildrenFromNode:(xmlNodePtr)genericPtr];
+
+	Class type = [[self class] replacementClassForClass:[DDXMLNode class]];
+	[type removeAllChildrenFromNode:(xmlNodePtr)genericPtr];
 
 	NSUInteger i;
 	for (i = 0; i < [children count]; i++)