This is a div with...
data-demo-html="true" to include the markup in this div in the source code view.
data-demo-js="true" to include all scripts from the head in the source code view.
data-demo-css="true" to include all style from the head in the source code view.
This is a div with...
data-demo-html="#myMarkup" to include specific markup in the source code view.
data-demo-js="#myScript" to include a specific script from the head in the source code view.
data-demo-css="#myStyle" to include a specific style from the head in the source code view.
data-demo-php="source.php" to include PHP script from source.php, which is the plain text version of file-name.php, in the source code view (see files in this folder).