TYPO3 - Flexform selectSingle set fieldControl

Question

I would like to achieve that an editor can add values for the select field himself. Therefor I would like to change settings for the fieldControl option of a selectSingle in flexform.

I found an example for TCA:

[
    'columns' => [
        'select_multiplesidebyside_6' => [
            'exclude' => 1,
            'label' => 'select_multiplesidebyside_6 fieldControl',
            'config' => [
                'type' => 'select',
                'renderType' => 'selectMultipleSideBySide',
                'foreign_table' => 'tx_styleguide_staticdata',
                'size' => 5,
                'autoSizeMax' => 20,
                'fieldControl' => [
                    'editPopup' => [
                        'disabled' => false,
                        'options' => [
                            'windowOpenParameters' => 'height=300,width=500,status=0,menubar=0,scrollbars=1',
                        ],
                    ],
                    'addRecord' => [
                        'disabled' => false,
                    ],
                    'listModule' => [
                        'disabled' => false,
                    ],
                ],
            ],
        ],
    ],
]

I've already tried something like this, but I didn't get it to work.

<settings.test>
    <TCEforms>
        <label>label</label>
        <config>
            <type>select</type>
            <renderType>selectSingle</renderType>                                
            <fieldControl>
                <addRecord>
                    <disabled>false</disabled>
                </addRecord>
            </fieldControl>
        </config>
    </TCEforms>
</settings.test>

Answer 1

I had the same issue and debugged the code. The following is working for me:

 <fieldControl>
     <addRecord>
         <disabled type="boolean">0</disabled>
     </addRecord>
 </fieldControl>

The "Trick" is to use the type attribute in order to tell the parser to cast the value to a boolean. Then use a falsy value, e.g. the number 0 but not the string false.