Hi!
I send mail wit Email_Template.
My problem is that I have a checkbox and I'm unable to print data in my email template because I have an error:

ArrayData::__construct: Parameter needs to be an object or associative array
At line 39 in E:\_silverstripe_cms\silverstripe\sapphire\core\ArrayData.php

The proble is how write data in checkbox. Can you hel me?
This is my checkbox:

new CheckboxSetField(
            $name = "topics",
            $title = "Settori d'interesse:",
            $source = array(
             "1" => "Information Management",
             "2" => "Application Integration (EAI)",
             "3" => "System Management",
             ),
            $value = ""
               )

and in GenericEmail.ss I wrote: Settori d'interesse: $topics

I think the form returns an array ... So depending on what you need to do , you could either implode it into a string (for , say , displaying it in a mail) and feed it to the template or convert it into viewable data for Silverstripe using ArrayData() ...

See:
http://doc.silverstripe.com/doku.php?id=arraydata&s=arraydata

or

http://doc.silverstripe.com/doku.php?id=tutorial:3-forms&s=arraydata

Good luck !

Well.. A very easy way is converting the values to a string .. ;-)

e.g. :

$data['Checkbox_String'] = implode("<br/>",$data['Checkboxes']);