How to write site protocol in xml?

Question

XML

It is required to do that there was an automatic substitution of the link, depending on the protocol used to enter the site. Those. if I open xml at http://site.dev/file.xml , it should contain

<?xml version="1.0"?>
<steps>
<step>
<url>http://site.dev/</url>
</step>
</steps>

if I open xml at https://site.dev/file.xml , then it should contain

<?xml version="1.0"?>
<steps>
<step>
<url>https://site.dev/</url>
</step>
</steps>

How can this be done?