iron-form works with native and custom elements, and can prevent automatic redirectionsubmit(),
using a native button, or by wrapping a paper-button in a native button:iron-form-presubmit eventiron-form reacting to state changesThis form will have the "Submit" button disabled until all fields
are valid, and then show a paper-spinner during submission.
novalidate form attributeiron-form respects nested elements