How to convert currency to number?

Question

Yii

I am using maskedinput yii2 widget. After saving, it does not save me, writes that the field must be a number. How to convert to number and remove all other characters?
Here is the code I am using

<?= $form->field($model, 'oplata')->widget(MaskedInput::className(), [
                    'clientOptions' => [
                        'alias' => 'decimal',
                        'groupSeparator' => '.',
                        'autoGroup' => true,
                    ],
                'options' => ['placeholder' => 'Cтоимость', 'class' => 'inputWidget-form'],
            ])->label(false) ?>

Answer 1

Please show the rule for this field from the model and the data entry format.