How to pre-select a form radio item with Symfony 2?

Question

I'm working on a language choice form:

    $currentLocale = "en_US"; // This is indeed sent to the formType

    $langs = array(
        'fr_FR' => 'fr',
        'en_US' => 'en'
        );

    $builder->add('language', 'language', array(
        'choices' => $langs,
        'expanded' => true,
        'multiple' => false,
        'required' => false,
        'label' => false,
    ));

The HTML code looks like this (simplified):

<div id="languageForm_language">
    <input type="radio" value="fr_FR">
    <input type="radio" value="en_US">
</div>

How could I get the second item pre-selected, according to the $currentLocale value ?

Answer 1

In your $langs array you can specify key value pairs like this:

array(
  0 => 'value1',
  1 => 'value2'
)

Now, e.g. you want to preselect value2, you can set the data attribute to the key from value2:

$builder->add('language', 'choice', array(
    'choices' => $langs,
    'expanded' => true,
    'multiple' => false,
    'required' => false,
    'label' => false,

    'data' => 1
));

According to this, you can set your data attribute to your $currentLocale variable to preselect it. Your code should look like this:

$currentLocale = "en_US"; // This is indeed sent to the formType

$langs = array(
    'fr_FR' => 'fr',
    'en_US' => 'en'
);

$builder->add('language', 'choice', array(
    'choices' => $langs,
    'expanded' => true,
    'multiple' => false,
    'required' => false,
    'label' => false,
    'data' => $currentLocale
));

Note: the second parameter from the add() method should be choice not language.

Answer 2

If the form is used with a model object, just set the language on the object itself before passing it to the form:

$object->setLanguage($currentLocale);
$form = $this->createForm('some_form_type', $object);

Otherwise, set the data option to the default language key:

$builder->add('language', 'language', array(
    'choices' => $langs,
    'data'    => $currentLocale,
    // ...
));