php中的XML DOM（10）

1.PHP DOM (1)

Php中的DOM跟javascript不一样，属性不用另外增加一个节点

2.主要类

     DOMDocument ：文档类

     DOMNodeList ：节点列表类

     DOMNode ：节点类

     DOMElement ：元素类

3. DOMDocument类

  3.1创建文档对象

     DOMDocument::__construct ([ string $version [, string $encoding ]] )

     [ string $version ：版本号

     [, string $encoding ]]：字符集

  3.2、加载xml文件

     mixed DOMDocument::load ( string $filename)

     string $filename：要加载的xml文件名称

  3.3、获取节点

     DOMNodeList DOMDocument::getElementsByTagName ( string name )

     String name：要获取的节点名

示例：Demo.php

<span>php
    header ( </span><span>'</span><span>Content-Type:text/html;charset=gb2312</span><span>'</span><span> );
</span><span>//</span><span> 利用php解析demo01.xml
</span><span>//</span><span> 实例化dom对象</span>
    $dom = <span>new</span><span> DOMDocument ();
</span><span>//</span><span> 加载xml文件</span>
    $dom->load ( <span>'</span><span>demo01.xml</span><span>'</span><span> );
</span><span>//</span><span> 通过dom对象获取person节点，注意：这里返回值是一个DOMNodeList类对象</span>
    $persons = $dom->getElementsByTagName ( <span>'</span><span>person</span><span>'</span><span> );
</span><span>//</span><span> 共有几个person</span>
    echo <span>'</span><span>共有</span><span>'</span> . $persons->length . <span>'</span><span>个人<br></span><span>'</span>;      <span>//</span><span>输出共有两个人
</span><span>//</span><span> 选中索引为0的person，也就是第一个人</span>
    $person = $persons->item ( <span>0</span><span> );
</span><span>//</span><span> 在这个person下获取name节点，返回的仍然是一个DOMNodeList类对象</span>
    $names = $person->getElementsByTagName ( <span>'</span><span>name</span><span>'</span><span> );    
</span><span>//</span><span> 输出姓名</span>
echo $names->item ( <span>0</span> )->nodeValue . <span>'</span><span><br></span><span>'</span>;       <span>//</span><span>输出'张三'</span>
为什么要进行两次取的Nodelist呢？请参照上图，因为有两个节点

demo.xml

<?xml version=<span>"<span>1.0</span><span>"</span> encoding=<span>"</span><span>UTF-8</span><span>"</span>?>
<persons>
    <person id="<span">"<span>s101</span><span>"</span>>
        <name>zhangsan</name>
        <age><span>30</span></age>
    </person>
    <person>
        <name>wangwu</name>
        <age><span>18</span></age>
    </person>
</persons>

4. DOMNodeList类 （上面的person就是NodeList节点）

  1、Length

     当前节点列表中共有几个节点

  2、DOMElement DOMNodelist::item ( int $index )

     选中索引为index的节点

     int $index：索引

5、 DOMNode类

     1、nodeValue 节点的值

6、 关于属性的读取

   1、bool DOMElement::hasAttribute ( string $name )

      判断是否具有某个属性（只判断某个属性下有没有）

      String $name：属性名

   2、bool DOMNode::hasAttributes ( void )

      判断是否具有属性（只要有属性就返回true）

   3、string DOMElement::getAttribute ( string $name )

      获取指定属性的属性值

String $name：属性名

示例2.用连贯操作输出

<span>php
    $dom </span>= <span>new</span> DOMDocument ( <span>'</span><span>1.0</span><span>'</span>, <span>'</span><span>utf-8</span><span>'</span><span> );
    $dom</span>->load ( <span>'</span><span>demo01.xml</span><span>'</span><span> );
</span><span>//</span><span> 想得到第一个人的姓名</span>
    echo $dom->getElementsByTagName ( <span>'</span><span>person</span><span>'</span> )->item ( <span>0</span><span> )
    </span>->getElementsByTagName ( <span>'</span><span>name</span><span>'</span> )->item ( <span>0</span> )-><span>nodeValue;
输出：张三</span>

Example3：

<span>php
    header ( </span><span>'</span><span>Content-Type:text/html;charset=gb2312</span><span>'</span><span> );
    $dom </span>= <span>new</span> DOMDocument ( <span>'</span><span>1.0</span><span>'</span>, <span>'</span><span>utf-8</span><span>'</span><span> );
    $dom</span>->load ( <span>'</span><span>demo01.xml</span><span>'</span><span> );
    $person </span>= $dom->getElementsByTagName ( <span>'</span><span>person</span><span>'</span> )->item ( <span>0</span><span> );
</span><span>//</span><span> 判断节点是否具有id属性</span>
    <span>if</span> ($person->hasAttribute ( <span>'</span><span>id</span><span>'</span><span> )) {
        echo </span><span>'</span><span>具有id属性</span><span>'</span><span>;
    } </span><span>else</span><span> {
        echo </span><span>'</span><span>没有id属性</span><span>'</span><span>;
    }
    echo </span><span>'</span><span><br></span><span>'</span><span>;
</span><span>//</span><span> 判断节点是否具有属性</span>
    <span>if</span> ($person-><span>hasAttributes ()) {
        echo </span><span>'</span><span>有属性</span><span>'</span><span>;
    } </span><span>else</span><span> {
        echo </span><span>'</span><span>没有任何属性</span><span>'</span><span>;
    }
    echo </span><span>'</span><span><br></span><span>'</span><span>;
</span><span>//</span><span> 得到第一个person的id属性值</span>
    echo $person->getAttribute ( <span>'</span><span>id</span><span>'</span> );

之前的例子只能得到一条数据，现在我想得到所有人的完整信息，该如何实现？

示例4：

如果这种有属性的，也要遍历出来呢？

<span>php
    header ( </span><span>'</span><span>content-type:text/html;charset=gb2312</span><span>'</span><span> );
    $dom </span>= <span>new</span> DOMDocument ( <span>'</span><span>1.0</span><span>'</span>, <span>'</span><span>utf-8</span><span>'</span><span> );
    $dom</span>->load ( <span>'</span><span>demo01.xml</span><span>'</span><span> );
</span><span>//</span><span> 得到所有person节点</span>
    $persons = $dom->getElementsByTagName ( <span>'</span><span>person</span><span>'</span><span> );
</span><span>//</span><span> 得到总人数</span>
    $count = $persons-><span>length;
    </span><span>for</span>($i = <span>0</span>; $i ) {
    <span>//</span><span> $person表示第i个人</span>
        $person = $persons-><span>item ( $i );
        echo </span><span>'</span><span>第</span><span>'</span> . ($i + <span>1</span>) . <span>'</span><span>个人的</span><span>'</span><span>;
        </span><span>if</span> ($person->hasAttribute ( <span>'</span><span>id</span><span>'</span><span> )) {
            echo </span><span>'</span><span>学号：</span><span>'</span> . $person->getAttribute ( <span>'</span><span>id</span><span>'</span><span> );
        }
        echo </span><span>'</span><span>姓名：</span><span>'</span> . $person->getElementsByTagName ( <span>'</span><span>name</span><span>'</span> )->item ( <span>0</span> )-><span>nodeValue;
        echo </span><span>'</span><span>年龄：</span><span>'</span> . $person->getElementsByTagName ( <span>'</span><span>age</span><span>'</span> )->item ( <span>0</span> )-><span>nodeValue;
        echo </span><span>'</span><span><br></span><span>'</span><span>;
    }
</span>?>

以上就介绍了php中的XML DOM（10），包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。