解读PHP DOMDocument在解析XML文件中的作用

在使用

关于用到的XML文件还以“Php Xml处理之simplexml使用方法浅谈”一文中的XML为例，文件名为：me.xml。代码如下：

PHP XML处理XML代码
 

1.  ?xml version="1.0" encoding="utf-8"?>   
2.  phplamp>   
3.  post>   
4.  title id="1">PHP XML处理介绍一 /title>   
5.  details>详细内容一 /details>   
6.  /post>   
7.  post>   
8.  title id="2">PHP XML处理介绍二 /title>   
9.  details>详细内容二 /details>   
10.  /post>   
11.  post>   
12.  title id="3">PHP XML处理介绍三 /title>   
13.  details>详细内容三 /details>   
14.  /post>   
15.  /phplamp>   

然后就需要用PHP DOMDocument去处理这个文件，将XML文件中的任何元素都解析出来。代码如下，里面有注释。

PHP DOMDocument解析XML文件的代码
 

<ol class="dp-xml">
<li class="alt"><span><span class="tag"><span> ?php   </span></span></span></li>
<li><span>// 首先要建一个DOMDocument对象   </span></li>
<li class="alt">
<span>$</span><span class="attribute">xml</span><span> = </span><span class="attribute-value">new</span><span> DOMDocument();   </span>
</li>
<li><span> </span></li>
<li class="alt"><span>// 加载Xml文件   </span></li>
<li>
<span>$xml-</span><span class="tag">></span><span>load("me.xml");   </span>
</li>
<li class="alt"><span> </span></li>
<li><span>// 获取所有的post标签   </span></li>
<li class="alt">
<span>$</span><span class="attribute">postDom</span><span> = $xml-</span><span class="tag">><br></span><span>getElementsByTagName("post");   </span>
</li>
<li><span> </span></li>
<li class="alt"><span>// 循环遍历post标签   </span></li>
<li><span>foreach($postDom as $post){   </span></li>
<li class="alt"><span>// 获取Title标签Node   </span></li>
<li>
<span>$</span><span class="attribute">title</span><span> = $post-</span><span class="tag">><br></span><span>getElementsByTagName("title");   </span>
</li>
<li class="alt"><span> </span></li>
<li><span>/**   </span></li>
<li class="alt"><span>* 要获取Title标签的Id属性要分两部走   </span></li>
<li>
<span>* 1. 获取title中所有属性的<br>列表也就是$title-</span><span class="tag">></span><span>item(0)-</span><span class="tag">></span><span>attributes   </span>
</li>
<li class="alt"><span>* 2. 获取title中id的属性，<br>因为其在第一位所以用item(0)   </span></li>
<li><span>*   </span></li>
<li class="alt"><span>* 小提示：   </span></li>
<li>
<span>* 若取属性的值可以用item(*)-</span><span class="tag">></span><span>nodeValue   </span>
</li>
<li class="alt">
<span>* 若取属性的标签可以用item(*)-</span><span class="tag">></span><span>nodeName   </span>
</li>
<li>
<span>* 若取属性的类型可以用item(*)-</span><span class="tag">></span><span>nodeType   </span>
</li>
<li class="alt"><span>*/   </span></li>
<li>
<span>echo "Id: " . $title-</span><span class="tag">></span><span>item(0)-</span><span class="tag">><br></span><span>attributes-</span><span class="tag">></span><span>item(0)-</span><span class="tag">></span><span>nodeValue . "</span><span class="tag"><span> </span><span class="tag-name">br</span><span> </span><span class="tag">/></span><span>";   </span></span>
</li>
<li class="alt">
<span>echo "Title: " . $title-</span><span class="tag">><br></span><span>item(0)-</span><span class="tag">></span><span>nodeValue . "</span><span class="tag"><span> </span><span class="tag-name">br</span><span> </span><span class="tag">/></span><span>";   </span></span>
</li>
<li>
<span>echo "Details: " . $post-</span><span class="tag">><br></span><span>getElementsByTagName("details")-</span><span class="tag">></span><span>i<br>tem(0)-</span><span class="tag">></span><span>nodeValue . "</span><span class="tag"><span> </span><span class="tag-name">br</span><span> </span><span class="tag">/></span><span class="tag"><span> </span><span class="tag-name">br</span><span> </span><span class="tag">/></span><span>";   </span></span></span>
</li>
<li class="alt"><span>}   </span></li>
<li>
<span class="tag">?></span><span>  </span>
</li>
</ol>

这只是一种方法，PHP DOMDocument相当强大，还有更多的解析方法与策略，等待您去发掘。