What is substitute for Magento's transactional email {{skin}} in PHP?

Question

I need to achieve this {{skin url="img/logo.png" _area="frontend" _package="my-package" _theme="default"}} via PHP. The reason is, rewriting email templates and extracting common templates of headers and footers into PHP part, leaving only text and simple HTML of emails in Magento's admin panel.

Answer 1

In a theme template you could use for example

$this->getSkinUrl('img/logo.png', [
    '_area'    => 'frontend',
    '_package' => 'my-package',
    '_theme'   => 'default',
]);