Moodle multi-select: linking over items - moodle

Question

I'm trying to use the multi-select form element in a Moodle database to generate a list of tags. I would like these tags to link to the relevant search page displaying the filtered results.
The following template code works for singly tagged items, but fails for items with multiple tags:
<a href='/view.php?mode=list&filter=[[Tags]]'>[[Tags]]</a>
Is there a way to loop over items in a multi-select? Something like:
[[for Tag in Tags]] <a href='/view.php?mode=list&filter=[[Tag]]'>[[Tag]]</a> [[/for]]

Answer 1

I'm not certain there is an easy way to do this using the method above. Though, I've hacked together some javascript to accomplish the same thing:
function init() {
var tags = document.getElementsByClassName('tags');
for (var i=0; i<tags.length; i++) {
tags[i].innerHTML = tags[i].innerHTML.replace(/\w[\w\s]+?(?=<br>)/g, function(n) {
return "<a href='view.php?d=16&mode=list&perpage=10&filter=1&f_81%5B%5D="+ escape(n) + "'>" + n + "</a>";
});
}
};
window.onload = init;

Answer 2

Assuming you have an edit_form.php with something like this
defined('MOODLE_INTERNAL') || die;
require_once($CFG->libdir . '/formslib.php');
class edit_form extends moodleform {
public function definition() {
$mform =& $this->_form;
$options = array('red' => 'red', 'blue' => 'blue', 'green' => 'green');
$select = $mform->addElement('select', 'tags', get_string('tags'), $options);
$select->setMultiple(true);
$this->add_action_buttons(false, get_string('submit'));
}
}
Then use this in your edit.php file
require_once(dirname(__FILE__) . '/edit_form.php');
...
$mform = new edit_form();
$mform->display();
if ($formdata = $mform->get_data()) {
foreach ($formdata->tags as $tag) {
$url = new moodle_url('/view.php', array('mode' => 'list', 'tag' => $tag));
echo html_writer::link($url, $tag);
}
}