Statamic plugin to check if variable contains a string

gistfile1.php

<?php

class Plugin_contains extends Plugin {

  public function index() {
  	
  	$needle = $this->fetchParam('needle', '', null, false, false);
  	$haystack = $this->context[$this->fetch('haystack')];

  	return strpos($haystack, $needle) ? $this->content : false;

  }
   
}