What is the difference between “someFunction()”, “JavaScript:somFuction()”, and “return someFunct()” in form onsubmit attribute?

I’m wondering the differences are between calling a JavaScript function in these different ways from a form. Method 1

Method 2

Render an iframe using formio

I’m tring to make a new formio.js component to render iframes because i want something easy to show PDF files for example but the iframe does not work. Everything is rendered except the iframe… I …