Load Server Side in iFrame instead of URL

Question

Is it possible iframe a source file from the server instead of a URL meaning instead of

   ---> Instead of
<iframe width='100%' height='100%' src='http://example.com/file.php' allowTransparency='yes' frameborder='no' scrolling='no' id='adminheader' > </iframe>

   ---> Load Server Side File
    
    <iframe width='100%' height='100%' src='/home/username/public_html/header.php' allowTransparency='yes' frameborder='no' scrolling='no' id='adminheader' > </iframe>

The aim to load the header only as is and if possible to access it indirectly applying certain styles and scripts.

Answer 1

No, since iframes are rendered client-side. But I don't see why you couldn't just load them with URL.

<iframe src='http://example.com/header.php'>