How to remove empty html tags (wich containing whitespaces and/or their html codes)

问题

Need a regex for preg_replace.

This question wasn't answered in "another question" because not all tags I want to remove aren't empty.

I have not only to remove empty tags from an HTML structure, but also tags containing line breaks as well as white spaces and/or their html code.

Possible Codes are:

<br />     &ensp; &emsp;      

BEFORE removing matching tags:

<div> 
  <h1>This is a html structure.</h1> 
  <p>This is not empty.</p> 
  <p></p> 
  <p><br /></p>
  <p> <br /> &;thinsp;</p>
  <p>&nbsp;</p> 
  <p> &nbsp; </p> 
</div>

AFTER removing matching tags:

<div> 
  <h1>This is a html structure.</h1> 
  <p>This is not empty.</p> 
</div>

回答1:

You can use the following:

<([^>\s]+)[^>]*>(?:\s*(?:<br \/>|&nbsp;|&thinsp;|&ensp;|&emsp;|&#8201;|&#8194;|&#8195;)\s*)*<\/\1>

And replace with '' (empty string)

See DEMO

Note: This will also work for empty html tags with attributes.

回答2:

Use tidy It uses the following function:

function cleaning($string, $tidyConfig = null) {
    $out = array ();
    $config = array (
            'indent' => true,
            'show-body-only' => false,
            'clean' => true,
            'output-xhtml' => true,
            'preserve-entities' => true 
    );
    if ($tidyConfig == null) {
        $tidyConfig = &$config;
    }
    $tidy = new tidy ();
    $out ['full'] = $tidy->repairString ( $string, $tidyConfig, 'UTF8' );
    unset ( $tidy );
    unset ( $tidyConfig );
    $out ['body'] = preg_replace ( "/.*<body[^>]*>|<\/body>.*/si", "", $out ['full'] );
    $out ['style'] = '<style type="text/css">' . preg_replace ( "/.*<style[^>]*>|<\/style>.*/si", "", $out ['full'] ) . '</style>';
    return ($out);
}

回答3:

I'm not so good with regex but, try this

\<.*\>\s*\&.*sp;\s*\<\/.*\>|\<.*\>\s*\<\s*br\s*\/\>\s*\&.*sp;\s*\<\/.*\>|\<.*\>\s*\&.*sp;\s*\<\s*br\s*\/\>\<\/.*\>

Basically matches

Tags with HTML space elements in them OR
Tags with breaks occurring before HTML space elements in them
Tags with breaks occurring after HTML space elements in them

来源：https://stackoverflow.com/questions/30865464/how-to-remove-empty-html-tags-wich-containing-whitespaces-and-or-their-html-cod

标签

php

html

regex

preg-replace