PHP trim_text() function – shorten text without cutting words in half

Here’s another PHP function I cannot live without – I add this into my standard PHP functions include on all projects. Often when displaying text, I am forced to abbreviate the text to a certain number of characters. You might jump in a decide to use substring() on your text to achieve this abbreviation, but that can cause several problems. The most blatant is that you will often split the text right in the middle of a word. In addition, if there are any HTML tags in the text, they could get cut in the middle too, or have the closing tag left off completely, potentially breaking the display or exposing the remaining part of the tag.

As a solution to these problems, I have written a function that only trims on the last space before the number of characters you specify, so it will never cut words in half. Also, it strips out HTML tags before doing the character trim, preventing possible display issues. And, as a convenience it adds ellipses (the …) to all trimmed text, as a visual cue to the reader that the text has been abbreviated.

 * trims text to a space then adds ellipses if desired
 * @param string $input text to trim
 * @param int $length in characters to trim to
 * @param bool $ellipses if ellipses (...) are to be added
 * @param bool $strip_html if html tags are to be stripped
 * @return string 
function trim_text($input, $length, $ellipses = true, $strip_html = true) {
	//strip tags, if desired
	if ($strip_html) {
		$input = strip_tags($input);
	//no need to trim, already shorter than trim length
	if (strlen($input) <= $length) {
		return $input;
	//find last space within length
	$last_space = strrpos(substr($input, 0, $length), ' ');
	$trimmed_text = substr($input, 0, $last_space);
	//add ellipses (...)
	if ($ellipses) {
		$trimmed_text .= '...';
	return $trimmed_text;