FeedReader plugin

- reserved service id
- reworked error codes
- added xpath manipulation and basic gui elements in preview dialog

git-svn-id: http://svn.code.sf.net/p/retroshare/code/branches/v0.5-gxs-b1@5514 b45a01b8-16f6-495d-af2f-9b41ad6348cc

plugins/FeedReader/util/XPathWrapper.h

@@ -0,0 +1,51 @@
+/****************************************************************
+ *  RetroShare GUI is distributed under the following license:
+ *
+ *  Copyright (C) 2012 by Thunder
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version 2
+ *  of the License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA  02110-1301, USA.
+ ****************************************************************/
+
+#ifndef XPATHWRAPPER
+#define XPATHWRAPPER
+
+#include <libxml/xpath.h>
+
+class XMLWrapper;
+
+class XPathWrapper
+{
+	friend class XMLWrapper;
+
+public:
+	~XPathWrapper();
+
+	void cleanup();
+
+	bool compile(const char *expression);
+
+	unsigned int count();
+	xmlNodePtr node(unsigned int index);
+
+protected:
+	XPathWrapper(XMLWrapper &xmlWrapper);
+
+	XMLWrapper &mXMLWrapper;
+	xmlXPathContextPtr mContext;
+	xmlXPathObjectPtr mResult;
+};
+
+#endif