Remove all except inside tag

Question

How to remove all from page except text inside <p> tag?

Page:

  This is text.
  <div class="text">This is text in 'div' tag</div>
  <p>This is text in 'p' tag</p>

Expected result:

This is text in 'p' tag

Greetings.

Answer 1

Basically, you'll have to parse the markup. PHP comes with a good parser in the form of the DOMDocument class, so that's really quite easy:

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

Next, get all p tags:

$paragraphs = $dom->getElementsByTagName('p');

This method returns a DOMNodeList object, which implements the Traversable interface, so you can use it as an array of DOMNode instances (DOMElement in this case):

$first = $paragraphs->item(0);//or $paragraphs[0] even
foreach ($paragraphs as $p) {
    echo $p->textContent;//echo the inner text
}

If you only want the paragraph elements that do not contain child elements, then you can easily check that:

foreach ($paragraphs as $p) {
    if (!$p->hasChildNodes()) {
        echo $p->textContent; // or $p->nodeValue
    }
}

A closely related answer with some more links/info: How to split an HTML string into chunks in PHP?

Answer 2

You can easily do this with the native php strip_tags function like so:

strip_tags("<p>This is text in 'p' tag</p>"); 

Which will return as you expected, "This is text in 'p' tag". NOTE: this is only useful when you have an outer-container div, and you use a little bit of dirty RegExp in order to strip not only the P, but the whole tags the user expected (ex. the div tag). This function has one argument, and a second optional argument. The first one is the string that you are stripping the tags from, and the second one specifies allowable tags that won't be stripped as a string. These tags will not be removed in the process. For more information on the strip_tags function click here.

I hope you got the idea :)