Displays the needle, and some surrounding text, within a haystack

Excerpt

function excerpt($text, $phrase, $radius = 50, $ending = "...", $offset = 0) {
	// excerpt('SuperLongStringThatMightNotFitInTheSpaceAllowed', 'That', 10)
	// will return
	// rLongStringThatMightNotFi...
	
	$phraseLen = strlen($phrase);
	if ($radius < $phraseLen) {
		$radius = $phraseLen;
	}

	$pos = strpos(strtolower($text), strtolower($phrase), $offset);
	
	$startPos = 0;
	if ($pos > $radius) {
		$startPos = $pos - $radius;
	}

	$textLen = strlen($text);

	$endPos = $pos + $phraseLen + $radius;
	if ($endPos >= $textLen) {
		$endPos = $textLen;
	}

	$excerpt = substr($text, $startPos, $endPos - $startPos);
	if ($startPos != 0) {
		$excerpt = substr_replace($excerpt, $ending, 0, $phraseLen);
	}

	if ($endPos != $textLen) {
		$excerpt = substr_replace($excerpt, $ending, -$phraseLen);
	}

	return $excerpt;
}