RapidXml用法
时间：2014-06-26 23:51:30
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一、写xml 文件
#include <iostream>
#include "rapidxml/rapidxml.hpp"
#include "rapidxml/rapidxml_utils.hpp"
#include "rapidxml/rapidxml_print.hpp"
using namespace rapidxml;
int main()
{
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;
system("PAUSE");
return EXIT_SUCCESS;
}
生成的xml例如以下
<?xml version="1.0" encoding="utf-8" ?> - <config> - <color> <red>0.1</red> <green>0.1</green> <blue>0.1</blue> <alpha>1.0</alpha> </color> - <size> <x>640</x> <y>480</y> </size> <mode fullscreen="false">screen mode</mode> </config>
写文件样例2：
#include <string>
#include <iostream>
#include <fstream>
#include "rapidxml/rapidxml.hpp"
#include "rapidxml/rapidxml_utils.hpp"
#include "rapidxml/rapidxml_print.hpp"
using namespace rapidxml;
using namespace std;
int main(int argc, char* argv[])
{
xml_document<> doc; //是解析器
char a[] = "<top>"//假设单独传, 就不能加上xml的头部信息，
//否则会报错
"<name>tangqiang</name>"
"<age>22</age>"
"</top>";
char* p = a;
doc.parse<0>(p);
xml_node<>* node = doc.first_node();//去顶级结点
cout << (node->name())<< endl;
node = node->first_node();
while (node) {
cout << node->name() << node->value() << endl;//name() value()返回的字符串不会去掉首尾的空白字符
node = node->next_sibling();
}
ofstream out("test.xml");//ofstream 默认时，假设文件存在则会覆盖原来的内容，不存在则会新建
out << doc;//doc 这样输出时在目标文件里不会有xml 头信息---<?xml version=‘1.0‘ encoding=‘utf-8‘ >
out.close();
system("pause");
return 0;
}生成的xml例如以下
<top> <name>tangqiang</name> <age>22</age> </top>
二、读取xml文件
#include <iostream>
#include "rapidxml/rapidxml.hpp"
#include "rapidxml/rapidxml_utils.hpp"
#include "rapidxml/rapidxml_print.hpp"
using namespace rapidxml;
int main()
{
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
xml_node<>* root = doc.first_node();
std::cout<<root->name()<<std::endl;
//! 获取根节点第一个节点
xml_node<>* node1 = root->first_node();
std::cout<<node1->name()<<std::endl;
xml_node<>* node11 = node1->first_node();
std::cout<<node11->name()<<std::endl;
std::cout<<node11->value()<<std::endl;
//! 加入?之后再次保存
//须要说明的是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;
system("PAUSE");
return EXIT_SUCCESS;
}
生成的xml为
<config> <color> <red>0.1</red> <green>0.1</green> <blue>0.1</blue> <alpha>1.0</alpha> </color> <size> <x>640</x> <y>480</y> <w>0</w> <h>0</h> </size> <mode fullscreen="false">screen mode</mode> </config>
三、删除节点
#include "rapidxml/rapidxml.hpp"
#include "rapidxml/rapidxml_utils.hpp"
#include "rapidxml/rapidxml_print.hpp"
#include<iostream>
using namespace rapidxml;
int main()
{
file<> fdoc("config.xml");
xml_document<> doc;
doc.parse<0>(fdoc.data());
std::string text;
rapidxml::print(std::back_inserter(text), doc, 0);
std::cout<<text<<std::endl;
xml_node<>* root = doc.first_node();
xml_node<>* sec = root->first_node();
root->remove_node(sec); //移除根节点下的sec结点(包含该结点下全部结点)
text="删除一个节点\r\n";
rapidxml::print(std::back_inserter(text), doc, 0);
std::cout<<text<<std::endl;
root->remove_all_nodes(); //移除根节点下全部结点
text="删除全部节点\r\n";
rapidxml::print(std::back_inserter(text), doc, 0);
std::cout<<text<<std::endl;
std::ofstream out("test.xml");
out<<doc;
system("pause");
return 0;
}输出信息例如以下：
<config> <color> <red>0.1</red> <green>0.1</green> <blue>0.1</blue> <alpha>1.0</alpha> </color> <size> <x>640</x> <y>480</y> <w>0</w> <h>0</h> </size> <mode fullscreen="false">screen mode</mode> </config> 删除一个节点 <config> <size> <x>640</x> <y>480</y> <w>0</w> <h>0</h> </size> <mode fullscreen="false">screen mode</mode> </config> 删除全部节点 <config/>
四、编辑节点信息
临时找到的编辑方法就是先删除再添加?
#include "rapidxml/rapidxml.hpp"
#include "rapidxml/rapidxml_utils.hpp"
#include "rapidxml/rapidxml_print.hpp"
#include<iostream>
using namespace rapidxml;
int main()
{
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
xml_node<>* root = doc.first_node();
xml_node<>* delnode = root->first_node("color");
root->remove_node(delnode);//先删除address节点
//
xml_node<>* lnode = root->first_node("size");//找到post节点
xml_node<>* mynode=doc.allocate_node(node_element,"address","河北");
root->insert_node(lnode,mynode);
std::string text;
rapidxml::print(std::back_inserter(text),doc,0);
std::cout<<text<<std::endl;
std::ofstream out("version.xml");
out << doc;
system("pause");
return 0;
}输出例如以下：
<config> <color> <red>0.1</red> <green>0.1</green> <blue>0.1</blue> <alpha>1.0</alpha> </color> <size> <x>640</x> <y>480</y> <w>0</w> <h>0</h> </size> <mode fullscreen="false">screen mode</mode> </config> <config> <address>河北</address> <size> <x>640</x> <y>480</y> <w>0</w> <h>0</h> </size> <mode fullscreen="false">screen mode</mode> </config>
五、遍历全部节点
for(rapidxml::xml_node<char> * node = parent_node->first_node("node name");
node != NULL;
node = node->next_sibling())
{
...
}
六、遍历全部属性
for(rapidxml::xml_attribute<char> * attr = node->first_attribute("node name");
attr != NULL;
attr = attr->next_attribute())
{
char * value = attr->value();
}七、gcc使用-std=gnu++0x 编译rapidxml时会报错，错误信息大概例如以下
...rapidxml_print.hpp:120:23: error:
call to function ‘print_element_node‘ thatis neither visible in the
template definition nor found byargument-dependent lookup
out = print_element_node(out, node, flags,indent);
^
...rapidxml_print.hpp:242:22: note:
‘print_element_node‘ should be declaredprior to the call site or in
namespace ‘rapidxml‘
inline OutIt print_element_node(OutIt out,const xml_node<Ch> ...
经查，原来print_node()函数被其它函数调用，但在却没有定义(在被调用函数后定义了)，所以解决方法为把print_node()函数移到print_children(), print_element_node() 等函数的后面。在原定义处就留一个函数声明即可。
详细diff文件例如以下。
Index: rapidxml_print.hpp
===================================================================
--- rapidxml_print.hpp (revision 2025)
+++ rapidxml_print.hpp (revision 2080)
@@ -101,68 +101,9 @@
///////////////////////////////////////////////////////////////////////////
// Internal printing operations
-
- // 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;
- }
+ inline OutIt print_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);
// Print children of the node
template<class OutIt, class Ch>
@@ -372,7 +313,69 @@
*out = Ch(‘>‘), ++out;
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;
+ }
+
}
//! \endcond
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