[TYPO3-mvc] Fluid: form.select view helper and empty default item

[Susanne Moog]

Hey everyone,

I have a short question about the form.select view helper of fluid. How
do you handle select boxes that should start with an empty item
(optional attribute).

I want to render something like

<select name="category" size="1" id="category"><option value="">---</option>
<option value="cat1">cat1</option>
<option value="cat2">cat2</option>
<option value="cat3">cat3</option>
</select>

I'm using the following code atm (with the categories as object) and am
unsure how to get an empty object at the beginning:

<f:form.select property="category" options="{categories}"
optionLabelField="name" size="1" id="category" />

Thanks for any help,

Susanne