Use xmlSave for XML String creation.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@34929 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,4 +1,11 @@
-2012-03-14  Richard Frith-Macdonald & Fred Kiefer
+2012-03-12  Fred Kiefer <FredKiefer@gmx.de>
+
+	* Source/NSXMLPrivate.h: Add comments on owner policy.
+	* Source/NSXMLNode.m (-XMLStringWithOptions:): Reimplement to
+	allow closer control over output.
+	* Source/NSXMLDocument.m (-XMLStringWithOptions:): Remove this method.
+
+2012-03-14  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/NSXMLPrivate.h:
 	* Source/NSXMLNode.m:

Source/NSXMLDocument.m

@@ -365,23 +365,6 @@ GS_PRIVATE_INTERNAL(NSXMLDocument)
   return data;
 }
 
-- (NSString *) XMLStringWithOptions: (NSUInteger)options
-{
-  NSString	*string = nil;
-  xmlChar	*buf = NULL;
-  int		length;
-
-  xmlDocDumpFormatMemoryEnc(internal->node, &buf, &length, "utf-8",
-    ((options & NSXMLNodePrettyPrint) ? 1 : 0));
-
-  if (buf != 0 && length > 0)
-    {
-      string = StringFromXMLString(buf, length);
-      free(buf);
-    }
-  return string;
-}
-
 - (id) objectByApplyingXSLT: (NSData*)xslt
                   arguments: (NSDictionary*)arguments
                       error: (NSError**)error

Source/NSXMLNode.m

@@ -904,7 +904,7 @@ execute_xpath(NSXMLNode *xmlNode, NSString *xpath_exp, NSString *nmspaces)
 - (NSString*) canonicalXMLStringPreservingComments: (BOOL)comments
 {
   // FIXME ... generate from libxml
-  return [self notImplemented: _cmd];
+  return [self XMLStringWithOptions: NSXMLNodePreserveWhitespace];
 }
 
 - (NSXMLNode*) childAtIndex: (NSUInteger)index
@@ -1016,6 +1016,7 @@ execute_xpath(NSXMLNode *xmlNode, NSString *xpath_exp, NSString *nmspaces)
         }
       [subNodes release];
 
+      [internal->URI release];
       [internal->objectValue release];
       [internal->subNodes release];
       if (node)
@@ -1504,20 +1505,32 @@ execute_xpath(NSXMLNode *xmlNode, NSString *xpath_exp, NSString *nmspaces)
 {
   NSString     *string = nil;
   xmlChar      *buf = NULL;
-  xmlDocPtr    doc;
   xmlBufferPtr buffer;
   int error = 0;
   int len = 0;
+  xmlSaveCtxtPtr ctxt;
+  int xmlOptions = 0;
 
-  if (internal->node->type == XML_NAMESPACE_DECL)
-    {
-      xmlNsPtr	ns = (xmlNsPtr)internal->node;
-
-      return StringFromXMLStringPtr(ns->href);
-    }
   buffer = xmlBufferCreate();
-  doc = internal->node->doc;
-  error = xmlNodeDump(buffer, doc, internal->node, 1, 1);
+
+  // XML_SAVE_XHTML XML_SAVE_AS_HTML XML_SAVE_NO_DECL XML_SAVE_NO_XHTML
+  xmlOptions |= XML_SAVE_AS_XML;
+  if (options & NSXMLNodePreserveWhitespace)
+    {
+      xmlOptions |= XML_SAVE_WSNONSIG;
+    }
+  if (options & NSXMLNodeCompactEmptyElement)
+    {
+      xmlOptions |= XML_SAVE_NO_EMPTY;
+    }
+  if (options & NSXMLNodePrettyPrint)
+    {
+      xmlOptions |= XML_SAVE_FORMAT;
+    }
+  
+  ctxt = xmlSaveToBuffer(buffer, "utf-8", xmlOptions);
+  xmlSaveTree(ctxt, internal->node);
+  error = xmlSaveClose(ctxt);
   if (-1 == error)
     {
       xmlBufferFree(buffer);

Source/NSXMLPrivate.h

@@ -86,25 +86,32 @@ StringFromXMLString(const unsigned char *bytes, unsigned length)
  *
  * The 'kind' tells us what sort of node this is.
  * The 'node' points to the underlying libxml2 node structure.
- * The 'nsParent' points to the parent node of a namspace structure, needed
- *   because older (but still used on at least one major linux distribution)
- *   versions of libxml2 don't have a link to the parent of a namespace.
  * The 'options' field is a bitmask of options for this node.
  * The 'objectValue' is the object value set for the node.
+ * The 'subNodes' array is used to retain the objects pointed to by subnodes.
  *
- * The 'subNodes' array is confusing ... what *is* the ownership policy for
- * NSXMLNode with respect to the libxml2 tree?  The simple/obvious one would
- * be that each NSXMLNode owns any NSXMLNode pointed to by children of the
- * corresponding libxml2 structure ... in which case there would be no need
- * for this array because the references to the owned NSXMLNode instances
- * would be the'_private' fields of the libxml2 structures.
+ * When we create an Objective-C object for a node we also create objects
+ * for all parents up to the root object. (Reusing existing once as we find 
+ * them in the _private points of parent nodes)
+ * This adds the object to the subnode array of the parent object, retaining 
+ * the object in this process.
+ * This means a document object will retain all the objects we have created
+ * for its node tree, but we don't have to create all these objects at once.
+ * When we remove an object from its parent we always call the detach method.
+ * Here we unlink the libxml2 node and remove the object from its parent's
+ * subnode array, This will release the object.
+ * When an object gets deallocated it detaches all the subnodes, releasing
+ * them in the process and then it frees the node. That way each object takes
+ * care of freeing its own node, but nodes that don't have objects attached
+ * to them will get freed when their parent object (e.g. the NSXMLDocument)
+ * gets deallocated.
+ * For namespace nodes special rules apply as they don't have a parent pointer.
  *
  * URI is probably not needed at all ... I'm not sure
  */
 #define GS_NSXMLNode_IVARS \
   NSUInteger	  kind; \
   GS_XMLNODETYPE *node;  \
-  xmlNodePtr	  nsParent; \
   NSUInteger      options; \
   id              objectValue; \
   NSString       *URI; \
@@ -193,6 +200,7 @@ StringFromXMLString(const unsigned char *bytes, unsigned length)
 #include <libxml/parserInternals.h>
 #include <libxml/HTMLparser.h>
 #include <libxml/xmlmemory.h>
+#include <libxml/xmlsave.h>
 #include <libxml/xpath.h>
 #include <libxml/xpathInternals.h>