A submit button.
A submit button must be placed within a form.
When the user presses the submit button, the form is submitted. The value of the
This is the *action* code (a string) associated with this submit button. By default, action is "submit". This value is passed along to the server-side property nextPage as
If defined, the URL to go to after this form is submitted successfully. This value, if defined, will override the
nextPageof the form.
Subclasses implement this in order to render the static HTML contents of a component.
Internal onclick handler method for submit button. Users should not call this method.