I have just started reading documentation and examples about DOM, in order to crawl and parse the document.
For example I have part of document shown below:
<div id="showContent"> <table> <tr> <td> Crap </td> </tr> <tr> <td width="172" valign="top"><a href="link"><img height="91" border="0" width="172" class="" src="img"></a></td> <td width="10"> </td> <td valign="top"><table cellspacing="0" cellpadding="0" border="0"> <tbody><tr> <td height="30"><a class="px11" href="link">title</a><a><br> <span class="px10"></span> </a></td> </tr> <tr> <td><img height="1" width="580" src="crap"></td> </tr> <tr> <td align="right"> <a href="link"><img height="16" border="0" width="65" src="/buy"></a> </td> </tr> <tr> <td valign="top" class="px10"> <p style="width: 500px;">description.</p> </td> </tr> </tbody></table></td> </tr> <tr> <td> Crap </td> </tr> <tr> <td> Crap </td> </tr> </table> </div>
I'm trying to use the following code to get all the tr
tags and analyze whether there is crap or information inside them:
$dom = new DOMDocument(); @$dom->loadHTML($html); $xpath = new DOMXPath($dom); $tags = $xpath->query('.//div[@id="showContent"]'); foreach ($tags as $tag) { $string=""; $string=trim($tag->nodeValue); if(strlen($string)>3) { echo $string; echo '<br>'; } }
However I'm getting just stripped string without the tags, for example:
Crap Crap Title Description
But I would like to get:
<tr> <td>Crap</td> </tr> <tr> <a href="link">title</a> </tr>
How to keep html nodes (tags)?
The XML Document Object Model (DOM) class is an in-memory representation of an XML document. The DOM allows you to programmatically read, manipulate, and modify an XML document. The XmlReader class also reads XML; however, it provides non-cached, forward-only, read-only access.
Dom parser travels based on tree based and before access the data, it will load the data into dom object and it will update the data to the web browser. Below Example shows how to get access to the HTML data in web browser. <? $cols->item(0)->nodeValue.
The DOMDocument::getElementsByTagName() function is an inbuilt function in PHP which is used to return a new instance of class DOMNodeList which contains all the elements of local tag name.
The DOM implementation in PHP have more than 15 classes! But don't get afraid, for most cases, you might just end up using these ones: DOMNode, DOMDocument, DOMNodeList and DOMElement.
If you want to work with DOM you have to understand the concept. Everything in a DOM Document, including the DOMDocument, is a Node.
The DOMDocument is a hierarchical tree structure of nodes. It starts with a root node. That root node can have child nodes and all these child nodes can have child nodes on their own. Basically everything in a DOMDocument
is a node type of some sort, be it elements, attributes or text content.
HTML Legend: / \ UPPERCASE = DOMElement HEAD BODY lowercase = DOMAttr / \ "Quoted" = DOMText TITLE DIV - class - "header" | \ "The Title" H1 | "Welcome to Nodeville"
The diagram above shows a DOMDocument with some nodes. There is a root element (HTML) with two children (HEAD and BODY). The connecting lines are called axes. If you follow down the axis to the TITLE element, you will see that it has one DOMText leaf. This is important because it illustrates an often overlooked thing:
<title>The Title</title>
is not one, but two nodes. A DOMElement with a DOMText child. Likewise, this
<div class="header">
is really three nodes: the DOMElement with a DOMAttr holding a DOMText. Because all these inherit their properties and methods from DOMNode, it is essential to familiarize yourself with the DOMNode class.
In practise, this means the DIV you fetched is linked to all the other nodes in the document. You could go all the way to the root element or down to the leaves at any time. It's all there. You just have to query or traverse the document for the wanted information.
Whether you do that by iterating the childNodes
of the DIV
or use getElementByTagName()
or XPath is up to you. You just have to understand that you are not working with raw HTML, but with nodes representing that entire HTML document.
If you need help with extracting specific information from the document, you need to clarify what information you want to fetch from it. For instance, you could ask how to fetch all the links from the table and then we could answer something like:
$div = $dom->getElementById('showContent'); foreach ($div->getElementsByTagName('a') as $link) { echo $dom->saveXML($link); }
But unless you are more specific, we can only guess which nodes might be relevant.
If you need more examples and code snippets on how to work with DOM browse through my previous answers to related questions:
By now, there should be a snippet for every basic to medium UseCase you might have with DOM.
To create a parser you can use htmlDOM.
It is very simple easy to use DOM parser written in php. By using it you can easily fetch the contents of div
tag.
For example, find all div
tags which have attribute id
with a value of text
.
$ret = $html->find('div[id=text]');
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With