TYPO3.Fluid

Currently only types which can be casted to string are support as values in hidden form fields. However, it should be possible to use (domain) objects as values:

    <f3:form method="post" action="create" object="invoice">
        <f3:form.textbox name="properties[title]" property="title" />
        <f3:form.textarea name="properties[description]" property="description" />
        <f3:form.hidden name="properties[customer]" value="{customer}" />
        <f3:form.submit>Create Invoice</f3:form.submit>
    </f3:form>

Internally Fluid would convert the object into an identity array (not clear yet, if / when it becomes array('__uuid' => '1234...') or array('__identity' => array('title' => 'the title', 'number' => 234)) which then is converted back to an object by FLOW3's MVC framework on processing the request after the form has been submitted.