The realization of the MXML
Contents
MXML (Minimal XML) is a small, fast and versatile library that reads a whole XML file and puts it in a DOM tree.
1.XML
XML特点和作用 :
- XML 指可扩展标识语言（ eXtensible Markup Language）
- XML 的设计宗旨是传输数据， 而非显示数据
- XML 标签没有被预定义。 您需要自行定义标签。
- 作为一种通用的数据存储和通信格式被广泛应用。
- 描述的数据作为一棵树型的结构而存在。
<?xml version="1.0" encoding="utf-8"?>
<books>
<book id="001">
<author>wanger</author>
</book>
</books>2.mxml写入操作
mxml既可以创建写入xml文件，也可以解析xml文件数据 写入示例:
#include"mxml.h"
int main()
{
// create a new xml
mxml_node_t *xml = mxmlNewXML("1.0");
//add a node name books
mxml_node_t *books = mxmlNewElement(xml,"books");
//add a node under books name book
mxml_node_t *book = mxmlNewElement(books,"book");
//set attr
mxmlElementSetAttr(book,"id","001");
mxml_node_t *author = mxmlNewElement(book,"author");
mxmlNewText(author,0,"wanger");
FILE* fp = fopen("book.xml","wb");
mxmlSaveFile(xml,fp,MXML_NO_CALLBACK);
fclose(fp);
mxmlDelete(xml);
return 0;
}3.mxml解析操作
解析步骤： 步骤：
- 打开一个xml文件
- 把文件加载到内存中，mxml_node_t mxmlLoadFile(mxml_node_t *top, FILE *fp,mxml_type_t (*cb)(mxml_node_t ));
- 查找待提取的节点标签：mxml_node_t *mxmlFindElement(mxml_node_t *node, mxml_node_t *top,const char *name, const char *attr,const char *value, int descend);
- 获取标签属性：const char *mxmlElementGetAttr(mxml_node_t *node, const char *name);
- 获取标签的文本内容： const char *mxmlGetText(mxml_node_t *node, int *whitespace);
- 释放节点，关闭文件 示例： 解析的文本：
<?xml version="1.0" encoding="utf-8"?>
<books>
<book id="001">
<author>wanger</author>
</book>
</books>代码：
#include"mxml.h"
#include<stdio.h>
int main()
{
FILE* fp = fopen("book.xml","r");
// jiazai xml
mxml_node_t* xml = mxmlLoadFile(NULL,fp,MXML_NO_CALLBACK);
mxml_node_t* book = NULL;
mxml_node_t* author = NULL;
// find note
book = mxmlFindElement(xml,xml,"book","id",NULL,MXML_DESCEND);
//get attr
author = mxmlFindElement(book,xml,"author",NULL,NULL,MXML_DESCEND);
if(author == NULL)
{
printf("author error\n");
}
else
{
printf("book id is:%s\n",mxmlElementGetAttr(book,"id"));
printf("author is:%s\n",mxmlGetText(author,NULL));
book = mxmlFindElement(xml,xml,"book","id",NULL,MXML_DESCEND);
}
mxmlDelete(xml);
fclose(fp);
return 0;
}结果：
book id is:001
author is:wanger4.mxml for循环解析长文件
xml文件:
<?xml version="1.0" encoding="utf-8"?>
<proto-meta-dump>
<proto name="AH">
<proto-class>crypto</proto-class>
<proto-suit>TCP/IP</proto-suit>
<proto-desc></proto-desc>
<dump-name></dump-name>
<meta-data name="">
<dump-on></dump-on>
<dump-format></dump-format>
<dump-name>totMeta</dump-name>
</meta-data>
<meta-data name="ah.spi">
<dump-on></dump-on>
<dump-format></dump-format>
<dump-name>SPI</dump-name>
</meta-data>
<meta-data name="ah.sequence">
<dump-on></dump-on>
<dump-format></dump-format>
<dump-name>seqNum</dump-name>
</meta-data>
<meta-data name="ah.length">
<dump-on></dump-on>
<dump-format></dump-format>
<dump-name>payLen</dump-name>
</meta-data>
<meta-data name="ah.icv">
<dump-on></dump-on>
<dump-format></dump-format>
<dump-name>ICV</dump-name>
</meta-data>
</proto>
...
</proto-meta-dump>解析代码：
//open xml file
FILE* fp = fopen(fileName,"r");
//create mxml tree head node
mxml_node_t* tree = mxmlLoadFile(NULL,fp,MXML_NO_CALLBACK);
//build head node:proto_meta_dump
//第一层
mxml_node_t* proto = NULL;
//第二层
mxml_node_t* class = NULL;
mxml_node_t* suit = NULL;
mxml_node_t* desc = NULL;
mxml_node_t* name = NULL;
//第三层
mxml_node_t* meta_data = NULL;
mxml_node_t* dump_on = NULL;
mxml_node_t* dump_format = NULL;
mxml_node_t* dump_name = NULL;
//遍历第一层proto，mxmlFindElement函数：寻找下一个proto节点
for(proto = mxmlFindElement(tree,tree,"proto","name",NULL,MXML_DESCEND);proto!=NULL;proto = mxmlFindElement(proto,tree,"proto","name",NULL,MXML_DESCEND)){
class = mxmlFindElement(proto,tree,"proto-class",NULL,NULL,MXML_DESCEND);
suit = mxmlFindElement(proto,tree,"proto-suit",NULL,NULL,MXML_DESCEND);
desc = mxmlFindElement(proto,tree,"proto-desc",NULL,NULL,MXML_DESCEND);
name = mxmlFindElement(proto,tree,"dump-name",NULL,NULL,MXML_DESCEND);
//拿到第一层数据
printf("|proto:%s\n",mxmlElementGetAttr(proto,"name"));
printf(" |----class:%s\n",mxmlGetText(class,NULL));
printf(" |----suit:%s\n",mxmlGetText(suit,NULL));
printf(" |----desc:%s\n",mxmlGetText(desc,NULL));
printf(" |----name:%s\n",mxmlGetText(name,NULL));
//遍历第二层meta-data
for(meta_data = mxmlFindElement(proto,proto,"meta-data","name",NULL,MXML_DESCEND);meta_data!=NULL;meta_data = mxmlFindElement(meta_data,proto,"meta-data","name",NULL,MXML_DESCEND)){
//拿到第二层数据
dump_on = mxmlFindElement(meta_data,proto,"dump-on",NULL,NULL,MXML_DESCEND);
dump_id = mxmlFindElement(meta_data,proto,"dump-id",NULL,NULL,MXML_DESCEND);
dump_format = mxmlFindElement(meta_data,proto,"dump-format",NULL,NULL,MXML_DESCEND);
dump_name = mxmlFindElement(meta_data,proto,"dump-name",NULL,NULL,MXML_DESCEND);
printf(...,mxmlGetText(...));
...
}
}
mxmlDelete(tree);
fclose(fp);