Zend Framework 2 filter / validate array of contents

Question

How do I apply a filter to a field element with the contents of an array?

For example:

$this->add(
  "name" => "tags",
  "type" => "text",
  "filter" => array(
    array("name" => "StripTags"),
    array("name" => "StringTrim")
  )
);

$tags[0] = "PHP";
$tags[1] = "CSS";

If I attempt to filter I receive an error saying a scalar object is excepted, array given.

Answer 1

This isn't really possible at this time. Your best bet is to use a Callback filter and filter each Item individually. Something like this

$this->add(
  "name" => "tags",
  "type" => "text",
  "filter" => array(
    array("name" => "Callback", "options" => array(
       "callback" => function($tags) {
          $strip = new \Zend\Filter\StripTags();
          $trim = new \Zend\Filter\StringTrim();
          foreach($tags as $key => $tag) {
            $tag = $strip->filter($tag);
            $tag = $trim->filter($tag);
            $tags[$key] = $tag;
          }
          return $tags;
    }))
  )
);