How specify parameter's format in Nelmio ApiDocBundle

Format column is designed only for datetime, date and choice types.

For datetime and date it represents the date format like Y-m-d H:i:s and the array of choices for choice.

I haven't found any documentation about it, so I had to look through the source code. This is FormTypeParser class, the place where FormType is actually parsed and and you can see how format field is set.

In FormTypeParserTest class you can see how to use it. Just pass the string parameter with format name for one of the available types and the parser will handle it.

UPDATE: You are to define your constrains inside your FormType class.

For example:

class TestType extends AbstractType
{
    /**
     * @Assert\Type("string")
     * @Assert\Length(min="10", max="255")
     * @Assert\Regex("/^[^<>]+$/i")
     */
    private $title;

    /**
     * @Assert\Type("string")
     * @Assert\Length(min="10", max="255")
     * @Assert\Regex("/^[^<>]+$/i")
     */
    private $content;

    /**
     * @Assert\Date()
     */
    private $created;

    public function getName()
    {
        return 'test';
    }
}

will be parsed into:

ValidationParser in doParse() method finds all constrains defined in your FormType class and then executes parseConstraint() method for each of them.

You can also use FormTypeParser as I described above. For example:

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder->add('created', 'date', array('label' => 'Created', 'format' => 'yyyy-MM-dd'))
        ->add('color', 'choice', array('label' => 'Color', 'choices' => array('grey' => '#CCCCCC', 'red' => '#FF0000')))
        ->add('save', 'submit');
}

will be parsed as:

Hope it helps now!

i submit a pull request that use validation metadata for format property.

you can see this PR here