Routing in cakephp 3.4

2

this is my view.ctp <?php echo $this->Html->link($school->name,

array(

   'controller' => 'schools',

   'action' => 'show', $school->id,

   'school_name' => strtolower(preg_replace('/\s+/', '_', $school->'name)),

   'ext' => 'school'

  )

);

 ?>