• Temporary remove all eventual HTML tags
• Trim stripped content at desired words length
• Get all HTML tags back on their initial positions
• Watch for unclosed tags

OK, I guess the task is quite clear. Now we gonna create a function, paste it at the bottom of ‘functions.php’ so it can be (re)used whenever is needed. I didn’t want to bother with making widget or plugin coz it takes more time and does the same job. Maybe one day I will. Here is our function:

<?php
function trim_the_content( $the_contents, $read_more_tag = ' READ MORE...', $perma_link_to = '', $all_words = 45 ) {
	// make the list of allowed tags
	$allowed_tags = array( 'a', 'abbr', 'b', 'blockquote', 'b', 'cite', 'code', 'div', 'em', 'fon', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'i', 'img', 'label', 'i', 'p', 'pre', 'span', 'strong', 'title', 'ul', 'ol', 'li', 'object', 'embed' );
	if( $the_contents != '' ) {
		// process allowed tags
		$allowed_tags = '<' . implode( '><', $allowed_tags ) . '>';
		$the_contents = str_replace( ']]>', ']]&gt;', $the_contents );
		$the_contents = strip_tags( $the_contents, $allowed_tags );
		// exclude HTML from counting words
		if( $all_words > count( preg_split( '/[\s]+/', strip_tags( $the_contents ), -1 ) ) ) return $the_contents;
		// count all
		$all_chunks = preg_split( '/([\s]+)/', $the_contents, -1, PREG_SPLIT_DELIM_CAPTURE );
		$the_contents = '';
		$count_words = 0;
		$enclosed_by_tag = false;
		foreach( $all_chunks as $chunk ) {
			// is tag opened?
			if( 0 < preg_match( '/<[^>]*$/s', $chunk ) ) $enclosed_by_tag = true;
			elseif( 0 < preg_match( '/>[^<]*$/s', $chunk ) ) $enclosed_by_tag = false;
			// get entire word
			if( !$enclosed_by_tag && '' != trim( $chunk ) && substr( $chunk, -1, 1 ) != '>' ) $count_words ++;
			$the_contents .= $chunk;
			if( $count_words >= $all_words && !$enclosed_by_tag ) break;
		}
                // note the class named 'more-link'. style it on your own
		$the_contents = $the_contents . '<a class="more-link" href="' . $perma_link_to . '">' . $read_more_tag . '</a>';
		// native WordPress check for unclosed tags
		$the_contents = force_balance_tags( $the_contents );
	}
	return $the_contents;
}
?>

How to use this code with your own theme templates?

That’s easy, the only thing you need to do is to call our function (pasted in functions.php, remember?) and pass required arguments or parameters. For example…instead of using either the_excerpt() or the_content() WP’s functions you would write something like this:

<?php
	// find out your post permalink
	$perma_link = get_permalink( $post->ID );
	// save original post content to variable
	$content = get_the_content();
	// prevent tags strip | it's a bug in WordPress!
	$content = apply_filters( 'the_content', $content );
	$content = str_replace( ']]>', ']]&gt;', $content );
	// throw out trimmed: content to process, read more tag, post permalink, words length
	echo trim_the_content( $content, 'READ MORE...', $perma_link, 45 );
?>

Hopefully you find this function useful so share it with others PLEASE! Thanks!

<?php
	the_content(); // this is your standard way to output Post or Page content
	// now the test
	$var_content = get_the_content();
	echo $var_content;
?>

It looks like paragraphs and break rules (<p> and <br />) are gone. Maybe some other tags too but I have noticed those two. I suppose not so many developers use get_the_content() function, however some of my themes (this one too) needs it in order to extract images or documents out of Post/Page content and still keep text formatted. We all know that the_excerpt() function will strip down each and every html tag so there’s no sense in using it, especially not in Post/Page details template.

Solution

It’s true there’s a solution at codex.wordpress.org but for those who have hard time to find it – here it is:

<?php
	the_content(); // this is your standard way to output Post or Page content
	// now the test which works
	$var_content = get_the_content();
	$var_content = apply_filters( 'the_content', $var_content );
	$var_content = str_replace( ']]>', ']]>', $var_content );
	echo $var_content;
?>

It should be OK now. Just wanted to pay your attention to this issue since WordPress developer team didn’t fix it until 2.8.4 – currently available for download. Maybe next time.