How to get data for Custom Validator?

below is code for my Custom Validator to see Atleast one option is selected in drop down menu....but when i try get the value of $attribute i am getting null Value but whereas the $validator has the value (of selected values)...Can anyone help me?

            <?php

use Phalcon\Validation\Validator;
use Phalcon\Validation\ValidatorInterface;
use Phalcon\Validation\Message;

class MultiSelectValidator extends Validator implements ValidatorInterface {

public function __construct($options = null) {
    parent::__construct($options);
    $this->setOption("cancelOnFail", true);
}

public function validate(Phalcon\Validation $validator, $attribute) {

    $array = $validator->getValue($attribute);//getting empty value
    var_dump($validator)
    if (empty($array)) {
        $message = $this->getOption('message');
        if (!$message) {
            $message = "Select Atleast One Wallet";
        }
        $validator->appendMessage(new Message($message, $attribute, 'IsSelected'));
        return FALSE;
    }
    return TRUE;
}
}

I had defined the attibute as an array()....

        $corporate_wallets = new Select('wallets_subscribed[]', $wallets, array(
            'multiple' => 'multiple',
            'useEmpty' => TRUE,
            'emptyText' => 'Select Wallets',
            'emptyValue' => '',
        ));
        $corporate_wallets->addValidators(array(
            new MultiSelectValidator(array(
                'message' => 'Choose atleast one  Wallet Types',
                    ))
        ));
        $corporate_wallets->setAttribute('id', 'wallettypes');
        $corporate_wallets->setLabel('Select Wallet Types');
        $this->add($corporate_wallets);

Hi @jaikumar002 Can you try with this please and tell me, use a generic name and set the real name in attribs

$corporate_wallets = new Select('walletsElement', $wallets, array(
            'multiple' => 'multiple',
            'useEmpty' => TRUE,
            'emptyText' => 'Select Wallets',
            'emptyValue' => '',
            'name' => 'wallets_subscribed[]'
        ));

How do you validate the form? $form->isValid($this->request->getPost())???