force_balance_tags

Source code

function force_balance_tags( $text ) {

	$tagstack = array();

	$stacksize = 0;

	$tagqueue = '';

	$newtext = '';

	$single_tags = array( 'br', 'hr', 'img', 'input' ); // Known single-entity/self-closing tags

	$nestable_tags = array( 'blockquote', 'div', 'span', 'q' ); // Tags that can be immediately nested within themselves



	// WP bug fix for comments - in case you REALLY meant to type '< !--'

	$text = str_replace('< !--', '<    !--', $text);

	// WP bug fix for LOVE ❤ (and other situations with '<' before a number)

	$text = preg_replace('#<([0-9]{1})#', '&lt;$1', $text);



	while ( preg_match("/<(\/?[\w:]*)\s*([^>]*)>/", $text, $regex) ) {

		$newtext .= $tagqueue;



		$i = strpos($text, $regex[0]);

		$l = strlen($regex[0]);



		// clear the shifter

		$tagqueue = '';

		// Pop or Push

		if ( isset($regex[1][0]) && '/' == $regex[1][0] ) { // End Tag

			$tag = strtolower(substr($regex[1],1));

			// if too many closing tags

			if( $stacksize <= 0 ) {

				$tag = '';

				// or close to be safe $tag = '/' . $tag;

			}

			// if stacktop value = tag close value then pop

			else if ( $tagstack[$stacksize - 1] == $tag ) { // found closing tag

				$tag = '</' . $tag . '>'; // Close Tag

				// Pop

				array_pop( $tagstack );

				$stacksize--;

			} else { // closing tag not at top, search for it

				for ( $j = $stacksize-1; $j >= 0; $j-- ) {

					if ( $tagstack[$j] == $tag ) {

					// add tag to tagqueue

						for ( $k = $stacksize-1; $k >= $j; $k--) {

							$tagqueue .= '</' . array_pop( $tagstack ) . '>';

							$stacksize--;

						}

						break;

					}

				}

				$tag = '';

			}

		} else { // Begin Tag

			$tag = strtolower($regex[1]);



			// Tag Cleaning



			// If self-closing or '', don't do anything.

			if ( substr($regex[2],-1) == '/' || $tag == '' ) {

				// do nothing

			}

			// ElseIf it's a known single-entity tag but it doesn't close itself, do so

			elseif ( in_array($tag, $single_tags) ) {

				$regex[2] .= '/';

			} else {	// Push the tag onto the stack

				// If the top of the stack is the same as the tag we want to push, close previous tag

				if ( $stacksize > 0 && !in_array($tag, $nestable_tags) && $tagstack[$stacksize - 1] == $tag ) {

					$tagqueue = '</' . array_pop ($tagstack) . '>';

					$stacksize--;

				}

				$stacksize = array_push ($tagstack, $tag);

			}



			// Attributes

			$attributes = $regex[2];

			if( !empty($attributes) )

				$attributes = ' '.$attributes;



			$tag = '<' . $tag . $attributes . '>';

			//If already queuing a close tag, then put this tag on, too

			if ( !empty($tagqueue) ) {

				$tagqueue .= $tag;

				$tag = '';

			}

		}

		$newtext .= substr($text, 0, $i) . $tag;

		$text = substr($text, $i + $l);

	}



	// Clear Tag Queue

	$newtext .= $tagqueue;



	// Add Remaining text

	$newtext .= $text;



	// Empty Stack

	while( $x = array_pop($tagstack) )

		$newtext .= '</' . $x . '>'; // Add remaining tags to close



	// WP fix for the bug with HTML comments

	$newtext = str_replace("< !--","<!--",$newtext);

	$newtext = str_replace("<    !--","< !--",$newtext);



	return $newtext;

}