[Flow] Usage of Multiselect

[Christian Loock]

Hello,

I have a problem with a Multiselect I am using to select roles.

Here is the form snippet I use:


<f:form.select multiple="true" name="roles" options="{availableRoles}"/>

{availableRoles} is a query result from the roleRepository.

I also added a Validator to my action that receives the form:

@Flow\Validate(argumentName="roles", type="NotEmpty")

However, when I submit the form, without having a role selected, I get 
the following error:

*#1297759968: Exception while property mapping for target type "array", 
at property path "": No converter found which can be used to convert 
from "string" to "array".* (More information 
<http://typo3.org/go/exception/1297759968>)

I tried tricking this error by adding a hidden field in front of my 
multiselect, to simulate a selection with an empty string. However, the 
Validator wont work here anymore.

I couldnt find anything about this googling. But I am sure, there must 
be a way to get this very basic usage of a multiselect to work and am 
probably just missing something.

Greetings,

Christian