Encore\Admin\Form\Field\SwitchField::render PHP Method

    public function render()
    {
        $key = array_search($this->value, $this->states);
        $this->value = $key == 'on' ? 'on' : 'off';
        $this->script = <<<EOT

\$('#{$this->id}_checkbox').bootstrapSwitch({
    size:'small',
    onSwitchChange: function(event, state) {
        \$('#{$this->id}').val(state ? 'on' : 'off');
    }
});;

EOT;
        return parent::render();
    }