RapidXml使用方法

一、写xml 文件

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#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如下

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<?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>

写文件例子2：

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#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>"//如果单独传, 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，如果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中不会有xml 头信息---<?xml version='1.0' encoding='utf-8' >

out.close();

system("pause");

return 0;

}

生成的xml如下

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<top>

<name>tangqiang</name>

<age>22</age>

</top>

二、读取xml文件

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#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;

//! 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;

system("PAUSE");

return EXIT_SUCCESS;

}

生成的xml为

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<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

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#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(包括该结点下所有结点)

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(); //移除根节点下所有结点

text="删除所有节点\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;

}

输出信息如下：

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<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>

删除所有节点

<config/>

四、编辑节点信息

暂时找到的编辑方法就是先删除再增加

[cpp] view plaincopy

#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;

}

输出如下：

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<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、遍历所有节点

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for(rapidxml::xml_node<char> * node = parent_node->first_node("node name");

node != NULL;

node = node->next_sibling())

{

...

}

六、遍历所有属性

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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，错误信息大概如下

...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> ...

在这里找到了解决方法。

经查，原来print_node()函数被其他函数调用，但在却未定义(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就行。

具体diff文件如下。

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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