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XMLTree.hpp

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/*
 * (C) Copyright 2002, Schlund+Partner AG
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifndef SP_GXML_XMLTREE_HPP
#define SP_GXML_XMLTREE_HPP

// STDC++
#include <string>
#include <memory>
#include <fstream>

// Local
#include <sp-gxmlcpp/XMLNodeSet.hpp>
#include <sp-gxmlcpp/XMLException.hpp>


/* NOTES
   o xmlChar is one byte.
   o "xmlChar" is compatible to "char"; xmlChar * Strings are always 0-terminated; (xmlChar *) is compatible to (char *)/string.c_str()
   o Simply using char *, string makes us still compatible with: UTF-8, ASCII, ISO-8859-*, ... (basically, all "up-to-8-Bits-Encodings").
   o UCS-2/UCS-4 encodings might be a problem.

   UNICODE  ISO 10646    All characters of the planet listed and labeled....

   UCS-2: 16-Bit Encoding of UNICODE.
   UCS-4: 32-Bit Encoding of UNICODE.
   UTF-8: 8-Bit Encoding of UNICODE. All todays ISO-8859-1 texts qualify as UTF-8. This is what UNIXses will do.
*/

namespace SP
{
namespace GXML
{

//
// XMLTree
//
class XMLTree
{
        /* enum Exceptions
                 {
                 PARSE_ERR=1,           // XML could not be parsed
                 CONTEXT_ERR,           // Could not create (XPath) context for Tree
                 NO_NODE_FROM_PATH_ERR, // Could not find node from specified path
                 NODE_CREATION_ERR,     // Could not create a node
                 NODE_ADDING_ERR,       // Could not add a creted node
                 TREE_INVALID_ERR       // Could not add a creted node
                 }; */
public:
        // Creators for char-Buffer, C++ string, ifstream
        XMLTree(const xmlDocPtr doc);
        XMLTree(const char * xmlBuffer, int size=-1);  // if size < 0, xmlBuffer must be a valid C-String!
        XMLTree(const std::string & xmlString);
        XMLTree(std::ifstream & xmlStream);
        XMLTree(std::istream & xmlStream);

        ~XMLTree();

        std::string getString( const std::string& xpath );
        bool getBool( const std::string& xpath );
        double getFloat( const std::string& xpath );

        // REMARK : the returned XMLNodeSet has to be freed by the calling method
        std::auto_ptr<XMLNodeSet> getNodeSet( const std::string& xpath );

        // Get internal libxml2 Pointers
        //  - this will allow us to call libxml2-Functions on the tree directly.
        //    (i.e., helling the abstraction for speed)
        xmlDocPtr getDocPtr() const;
        xmlXPathContextPtr getXPathContextPtr() const;

        // "Get Methods" based on "XPath"; paths are XPath Expressions;
        // all paths can be given an optional position
        //  - Methods delivering (xmlChar *) point into the tree
        //  - Methods delivering (std::string, int) obviously copy from tree
        //  - getValue-Methods will deliver the contents of the first child only
        //    e.g.: getValue("/req/X", 0) on
        // "<req><X>a b c<subtag>def</subtag></X></req>" returns: "a b c" only.

        // "libxml2"-Functions. Do not use if you want to be abstract.
        xmlChar * getXmlCharValue(const xmlChar * path) const;
        xmlChar * getXmlCharValue(const std::string & path) const;

        // "C++"-functions
        char * getAddrValue(const std::string & path) const;
        std::string getValue(const std::string & path) const;

        char * getAddrName(const std::string & path) const;
        std::string getName(const std::string & path) const;

        void setValue(const std::string & path, char * value);
        void setValue(const std::string & path, const std::string & value);

        /* Obsoleted by XMLDump
        // getTreeAsString=recursive: This gets the complete contents of the tag
        //  e.g.: getTreeAsString("/req/X", 0) on "<req><X>a b c<subtag>def</subtag>
        // </X></req>" returns: "<X>a b c<subtag>def</subtag></X>".
        std::string getTreeAsString(const std::string & path) const;
        */

        int getCount(const xmlChar * path) const;
        int getCount(const char * path) const;
        int getCount(const std::string & path) const;

        // "Modifying Methods" based on "XPath"; paths are XPath Expressions
        //  - Methods delivering (xmlChar *) point into the tree
        //  - Methods delivering (std::string, int) copy from tree
        void delTag(const std::string & path);
        void addTag(const std::string & path, const std::string & name, const std::string & content);

        void addSiblingTag(const std::string & path, const std::string & name, const std::string & content);

        std::string getSiblingXML( const std::string& path = "/*" );

        // addTree: Adds the whole tree as new child for node
        // This will COPY. No other method available from libxml2. We cannot mix trees.
        void addTree(const std::string & path, XMLTree * xmlTree);
        void addXML(const std::string & path, const std::string & xml);

        std::string getXML(const std::string & path="/") const;

        std::auto_ptr<XMLTree> getTree(const std::string &path="/");

        // Utility functions
        //
        // Node from Path
        static xmlNodePtr nodeFromPath(xmlXPathContextPtr context, const xmlChar * path);
        // Node from Path
        static xmlNodePtr nodeFromPath(xmlXPathContextPtr context, const std::string & path);

private:
        xmlDocPtr tree_;
        xmlXPathContextPtr context_;

        // Constructor helper function
        void genTree(const char * xmlBuffer, int size=-1);

        xmlXPathObjectPtr createXPathObject( const std::string& xpath );
        void destroyXPathObject( xmlXPathObjectPtr obj );
};

}}
#endif

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