php用正则表达式替换标签

Question

I searched in many forums about replacing the text between a tag, but all I get is how to remove text between tags etc. That's not what I'm looking for. Here is a little example so you can understand what I'm talking about. I want to replace:

<form action="link1" method="post" name="form" id="form">

What I want to do is to get rid of this form and changes it to:

<form action="link2" ....> 

Now, my problem is not about replacing but with choosing form tag.
I hope you understand me.

Answer 1

You have structured data (html are structured data), so use this structure. What you want to do is to change an attribute value, it's easy with DOMDocument:

$dom = new DOMDocument;
$dom->loadHTML($yourHTML);

$formTagList = $dom->getElementsByTagName('form');

foreach ($formTagList as $formNode) {
    if ($formNode->hasAttribute('action') && $formNode->getAttribute('action') === 'link1')
        $formNode->setAttribute('action', 'link2');
}

$result = $dom->saveHTML();

Answer 2

If you want to use a regular expression, then you should use preg_replace - http://php.net/manual/en/function.preg-replace.php . If you have a sample document, and the output you want, that would help too.

Answer 3

I'm not sure if I understood your question, but basing in your sample it's pretty simple. You can use this regex:

<form.*?>

And the replacement string

<form action="link2" ....> 

Working demo

Php code

$re = "/<form.*?>/"; 
$str = "<form action=\"link1\" method=\"post\" name=\"form\" id=\"form\"></form>"; 
$subst = "<form action=\"link2\" ....>"; 

$result = preg_replace($re, $subst, $str);

//result:
//     <form action="link2" ....></form>