Observes this field or form and submits the form when a value changes.
The form field will be assigned a CSS class up-active
while the autosubmitted form is processing.
The programmatic variant of this is the up.autosubmit() function.
Example
The following would submit the form whenever the
text field value changes:
<form method="GET" action="/search" up-autosubmit>
<input type="search" name="query">
</form>
The following would submit the form only if the query was changed,
but not if the checkbox was changed:
<form method="GET" action="/search">
<input type="search" name="query" up-autosubmit>
<input type="checkbox"> Include archive
</form>
