rapidxml学习

参考： 官网http://rapidxml.sourceforge.net/
https://blog.csdn.net/wqvbjhc/article/details/7662931
http://blog.sina.com.cn/s/blog_9b0604b40101o6fm.html

rapidxml_print.hpp修改代码：

#ifndef RAPIDXML_PRINT_HPP_INCLUDED
#define RAPIDXML_PRINT_HPP_INCLUDED
// Copyright (C) 2006, 2009 Marcin Kalicinski
// Version 1.13
// Revision $DateTime: 2009/05/13 01:46:17 $
//! \file rapidxml_print.hpp This file contains rapidxml printer implementation
#include "rapidxml.hpp"
// Only include streams if not disabled
#ifndef RAPIDXML_NO_STREAMS
#include <ostream>
#include <iterator>
#endif
namespace rapidxml
{
///
// Printing flags
const int print_no_indenting = 0x1;   //!< Printer flag instructing the printer to suppress indenting of XML. See print() function.
///
// Internal
//! \cond internal
namespace internal
{
///
// Internal character operations
// Copy characters from given range to given output iterator
template<class OutIt, class Ch>
inline OutIt copy_chars(const Ch *begin, const Ch *end, OutIt out)
{
while (begin != end)
*out++ = *begin++;
return out;
}
// Copy characters from given range to given output iterator and expand
// characters into references (&lt; &gt; &apos; &quot; &amp;)
template<class OutIt, class Ch>
inline OutIt copy_and_expand_chars(const Ch *begin, const Ch *end, Ch noexpand, OutIt out)
{
while (begin != end)
{
if (*begin == noexpand)
{
*out++ = *begin;    // No expansion, copy character
}
else
{
switch (*begin)
{
case Ch('<'):
*out++ = Ch('&'); *out++ = Ch('l'); *out++ = Ch('t'); *out++ = Ch(';');
break;
case Ch('>'): 
*out++ = Ch('&'); *out++ = Ch('g'); *out++ = Ch('t'); *out++ = Ch(';');
break;
case Ch('\''): 
*out++ = Ch('&'); *out++ = Ch('a'); *out++ = Ch('p'); *out++ = Ch('o'); *out++ = Ch('s'); *out++ = Ch(';');
break;
case Ch('"'): 
*out++ = Ch('&'); *out++ = Ch('q'); *out++ = Ch('u'); *out++ = Ch('o'); *out++ = Ch('t'); *out++ = Ch(';');
break;
case Ch('&'): 
*out++ = Ch('&'); *out++ = Ch('a'); *out++ = Ch('m'); *out++ = Ch('p'); *out++ = Ch(';'); 
break;
default:
*out++ = *begin;    // No expansion, copy character
}
}
++begin;    // Step to next character
}
return out;
}
// Fill given output iterator with repetitions of the same character
template<class OutIt, class Ch>
inline OutIt fill_chars(OutIt out, int n, Ch ch)
{
for (int i = 0; i < n; ++i)
*out++ = ch;
return out;
}
// Find character
template<class Ch, Ch ch>
inline bool find_char(const Ch *begin, const Ch *end)
{
while (begin != end)
if (*begin++ == ch)
return true;
return false;
}
///
// Internal printing operations
template<class OutIt, class Ch>
OutIt print_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);    
template<class OutIt, class Ch>
OutIt print_element_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);
template<class OutIt, class Ch>
OutIt print_data_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);
template<class OutIt, class Ch>
OutIt print_cdata_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);
template<class OutIt, class Ch>
OutIt print_declaration_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);
template<class OutIt, class Ch>
OutIt print_comment_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);
template<class OutIt, class Ch>
OutIt print_doctype_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);
template<class OutIt, class Ch>
OutIt print_pi_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);
// Print children of the node                               
template<class OutIt, class Ch>
inline OutIt print_children(OutIt out, const xml_node<Ch> *node, int flags, int indent)
{
for (xml_node<Ch> *child = node->first_node(); child; child = child->next_sibling())
out = print_node(out, child, flags, indent);
return out;
}
// Print node
template<class OutIt, class Ch>
inline OutIt print_node(OutIt out, const xml_node<Ch> *node, int flags, int indent)
{
// Print proper node type
switch (node->type())
{
// Document
case node_document:
out = print_children(out, node, flags, indent);
break;
// Element
case node_element:
out = print_element_node(out, node, flags, indent);
break;
// Data
case node_data:
out = print_data_node(out, node, flags, indent);
break;
// CDATA
case node_cdata:
out = print_cdata_node(out, node, flags, indent);
break;
// Declaration
case node_declaration:
out = print_declaration_node(out, node, flags, indent);
break;
// Comment
case node_comment:
out = print_comment_node(out, node, flags, indent);
break;
// Doctype
case node_doctype:
out = print_doctype_node(out, node, flags, indent);
break;
// Pi
case node_pi:
out = print_pi_node(out, node, flags, indent);
break;
// Unknown
default:
assert(0);
break;
}
// If indenting not disabled, add line break after node
if (!(flags & print_no_indenting))
*out = Ch('\n'), ++out;
// Return modified iterator
return out;
}
// Print attributes of the node
template<class OutIt, class Ch>
inline OutIt print_attributes(OutIt out, const xml_node<Ch> *node, int flags)
{
for (xml_attribute<Ch> *attribute = node->first_attribute(); attribute; attribute = attribute->next_attribute())
{
if (attribute->name() && attribute->value())
{
// Print attribute name
*out = Ch(' '), ++out;
out = copy_chars(attribute->name(), attribute->name() + attribute->name_size(), out);
*out = Ch('='), ++out;
// Print attribute value using appropriate quote type
if (find_char<Ch, Ch('"')>(attribute->value(), attribute->value() + attribute->value_size()))
{
*out = Ch('\''), ++out;
out = copy_and_expand_chars(attribute->value(), attribute->value() + attribute->value_size(), Ch('"'), out);
*out = Ch('\''), ++out;
}
else
{
*out = Ch('"'), ++out;
out = copy_and_expand_chars(attribute->value(), attribute->value() + attribute->value_size(), Ch('\''), out);
*out = Ch('"'), ++out;
}
}
}
return out;
}
// Print data node
template<class OutIt, class Ch>
inline OutIt print_data_node(OutIt out, const xml_node<Ch> *node, int flags, int indent)
{
assert(node->type() == node_data);
if (!(flags & print_no_indenting))
out = fill_chars(out, indent, Ch('\t'));
out = copy_and_expand_chars(node->value(), node->value() + node->value_size(), Ch(0), out);
return out;
}
// Print data node
template<class OutIt, class Ch>
inline OutIt print_cdata_node(OutIt out, const xml_node<Ch> *node, int flags, int indent)
{
assert(node->type() == node_cdata);
if (!(flags & print_no_indenting))
out = fill_chars(out, indent, Ch('\t'));
*out = Ch('<'); ++out;
*out = Ch('!'); ++out;
*out = Ch('['); ++out;
*out = Ch('C'); ++out;
*out = Ch('D'); ++out;
*out = Ch('A'); ++out;
*out = Ch('T'); ++out;
*out = Ch('A'); ++out;
*out = Ch('['); ++out;
out = copy_chars(node->value(), node->value() + node->value_size(), out);
*out = Ch(']'); ++out;
*out = Ch(']'); ++out;
*out = Ch('>'); ++out;
return out;
}
// Print element node
template<class OutIt, class Ch>
inline OutIt print_element_node(OutIt out, const xml_node<Ch> *node, int flags, int indent)
{
assert(node->type() == node_element);
// Print element name and attributes, if any
if (!(flags & print_no_indenting))
out = fill_chars(out, indent, Ch('\t'));
*out = Ch('<'), ++out;
out = copy_chars(node->name(), node->name() + node->name_size(), out);
out = print_attributes(out, node, flags);
// If node is childless
if (node->value_size() == 0 && !node->first_node())
{
// Print childless node tag ending
*out = Ch('/'), ++out;
*out = Ch('>'), ++out;
}
else
{
// Print normal node tag ending
*out = Ch('>'), ++out;
// Test if node contains a single data node only (and no other nodes)
xml_node<Ch> *child = node->first_node();
if (!child)
{
// If node has no children, only print its value without indenting
out = copy_and_expand_chars(node->value(), node->value() + node->value_size(), Ch(0), out);
}
else if (child->next_sibling() == 0 && child->type() == node_data)
{
// If node has a sole data child, only print its value without indenting
out = copy_and_expand_chars(child->value(), child->value() + child->value_size(), Ch(0), out);
}
else
{
// Print all children with full indenting
if (!(flags & print_no_indenting))
*out = Ch('\n'), ++out;
out = print_children(out, node, flags, indent + 1);
if (!(flags & print_no_indenting))
out = fill_chars(out, indent, Ch('\t'));
}
// Print node end
*out = Ch('<'), ++out;
*out = Ch('/'), ++out;
out = copy_chars(node->name(), node->name() + node->name_size(), out);
*out = Ch('>'), ++out;
}
return out;
}
// Print declaration node
template<class OutIt, class Ch>
inline OutIt print_declaration_node(OutIt out, const xml_node<Ch> *node, int flags, int indent)
{
// Print declaration start
if (!(flags & print_no_indenting))
out = fill_chars(out, indent, Ch('\t'));
*out = Ch('<'), ++out;
*out = Ch('?'), ++out;
*out = Ch('x'), ++out;
*out = Ch('m'), ++out;
*out = Ch('l'), ++out;
// Print attributes
out = print_attributes(out, node, flags);
// Print declaration end
*out = Ch('?'), ++out;
*out = Ch('>'), ++out;
return out;
}
// Print comment node
template<class OutIt, class Ch>
inline OutIt print_comment_node(OutIt out, const xml_node<Ch> *node, int flags, int indent)
{
assert(node->type() == node_comment);
if (!(flags & print_no_indenting))
out = fill_chars(out, indent, Ch('\t'));
*out = Ch('<'), ++out;
*out = Ch('!'), ++out;
*out = Ch('-'), ++out;
*out = Ch('-'), ++out;
out = copy_chars(node->value(), node->value() + node->value_size(), out);
*out = Ch('-'), ++out;
*out = Ch('-'), ++out;
*out = Ch('>'), ++out;
return out;
}
// Print doctype node
template<class OutIt, class Ch>
inline OutIt print_doctype_node(OutIt out, const xml_node<Ch> *node, int flags, int indent)
{
assert(node->type() == node_doctype);
if (!(flags & print_no_indenting))
out = fill_chars(out, indent, Ch('\t'));
*out = Ch('<'), ++out;
*out = Ch('!'), ++out;
*out = Ch('D'), ++out;
*out = Ch('O'), ++out;
*out = Ch('C'), ++out;
*out = Ch('T'), ++out;
*out = Ch('Y'), ++out;
*out = Ch('P'), ++out;
*out = Ch('E'), ++out;
*out = Ch(' '), ++out;
out = copy_chars(node->value(), node->value() + node->value_size(), out);
*out = Ch('>'), ++out;
return out;
}
// Print pi node
template<class OutIt, class Ch>
inline OutIt print_pi_node(OutIt out, const xml_node<Ch> *node, int flags, int indent)
{
assert(node->type() == node_pi);
if (!(flags & print_no_indenting))
out = fill_chars(out, indent, Ch('\t'));
*out = Ch('<'), ++out;
*out = Ch('?'), ++out;
out = copy_chars(node->name(), node->name() + node->name_size(), out);
*out = Ch(' '), ++out;
out = copy_chars(node->value(), node->value() + node->value_size(), out);
*out = Ch('?'), ++out;
*out = Ch('>'), ++out;
return out;
}
}
//! \endcond
///
// Printing
//! Prints XML to given output iterator.
//! \param out Output iterator to print to.
//! \param node Node to be printed. Pass xml_document to print entire document.
//! \param flags Flags controlling how XML is printed.
//! \return Output iterator pointing to position immediately after last character of printed text.
template<class OutIt, class Ch> 
inline OutIt print(OutIt out, const xml_node<Ch> &node, int flags = 0)
{
return internal::print_node(out, &node, flags, 0);
}
#ifndef RAPIDXML_NO_STREAMS
//! Prints XML to given output stream.
//! \param out Output stream to print to.
//! \param node Node to be printed. Pass xml_document to print entire document.
//! \param flags Flags controlling how XML is printed.
//! \return Output stream.
template<class Ch> 
inline std::basic_ostream<Ch> &print(std::basic_ostream<Ch> &out, const xml_node<Ch> &node, int flags = 0)
{
print(std::ostream_iterator<Ch>(out), node, flags);
return out;
}
//! Prints formatted XML to given output stream. Uses default printing flags. Use print() function to customize printing process.
//! \param out Output stream to print to.
//! \param node Node to be printed.
//! \return Output stream.
template<class Ch> 
inline std::basic_ostream<Ch> &operator <<(std::basic_ostream<Ch> &out, const xml_node<Ch> &node)
{
return print(out, node);
}
#endif
}
#endif

main.cpp

#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <functional>
#include <memory>
#include <sstream>
using namespace std;
//下面三个文件是本段代码需要的库文件
#include "rapidxml/rapidxml.hpp"
#include "rapidxml/rapidxml_utils.hpp"
#include "rapidxml/rapidxml_print.hpp"
using namespace rapidxml;
int CreateXml();
int ReadAndChangeXml();
int main()
{
CreateXml();
ReadAndChangeXml();
cout << "hello" << endl;
return 0;
}
//创建一个名称为config.xml文件
int CreateXml()
{
xml_document<> doc;  
xml_node<>* rot = doc.allocate_node(rapidxml::node_pi,doc.allocate_string("xml version='1.0' encoding='utf-8'"));
doc.append_node(rot);
xml_node<>* node =   doc.allocate_node(node_element,"config","information");  
xml_node<>* color =   doc.allocate_node(node_element,"color",NULL);  
doc.append_node(node);
node->append_node(color);
color->append_node(doc.allocate_node(node_element,"red","0.1"));
color->append_node(doc.allocate_node(node_element,"green","0.1"));
color->append_node(doc.allocate_node(node_element,"blue","0.1"));
color->append_node(doc.allocate_node(node_element,"alpha","1.0"));
xml_node<>* size =   doc.allocate_node(node_element,"size",NULL); 
size->append_node(doc.allocate_node(node_element,"x","640"));
size->append_node(doc.allocate_node(node_element,"y","480"));
node->append_node(size);
xml_node<>* mode = doc.allocate_node(rapidxml::node_element,"mode","screen mode");
mode->append_attribute(doc.allocate_attribute("fullscreen","false"));
node->append_node(mode);
std::string text;  
rapidxml::print(std::back_inserter(text), doc, 0);  
std::cout<<text<<std::endl; 
std::ofstream out("config.xml");
out << doc;
}
//读取并修改config.xml
int ReadAndChangeXml()
{
file<> fdoc("config.xml");
std::cout<<fdoc.data()<<std::endl;
xml_document<>   doc;
doc.parse<0>(fdoc.data());
std::cout<<doc.name()<<std::endl;
//! 获取根节点
rapidxml::xml_node<>* root = doc.first_node();
std::cout<<root->name()<<std::endl;
//! 获取根节点第一个节点
rapidxml::xml_node<>* node1 = root->first_node();
std::cout<<node1->name()<<std::endl;
rapidxml::xml_node<>* node11 = node1->first_node();
std::cout<<node11->name()<<std::endl;
std::cout<<node11->value()<<std::endl;
//! 添加之后再次保存
//需要说明的是rapidxml明显有一个bug
//那就是append_node(doc.allocate_node(node_element,"h","0"));的时候并不考虑该对象是否存在!
xml_node<>* size = root->first_node("size");
size->append_node(doc.allocate_node(node_element,"w","0"));
size->append_node(doc.allocate_node(node_element,"h","0"));
std::string text;
rapidxml::print(std::back_inserter(text),doc,0);
std::cout<<text<<std::endl;
std::ofstream out("config.xml");
out << doc;
}

编译：
g++ main.cpp -std=gnu++0x