Why JSF adds hidden field in an empty form?

Question

So this is my view:

<!DOCTYPE html>
<html xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core">
<h:head>
    <title>Welcome</title>
</h:head>
<h:body>
    <h:form id="myForm" prependId="false">
    </h:form>
</h:body>
</html>

And this is the source of the html output:

<!DOCTYPE html>
<html>
    <head>
        <title>Welcome</title>
     </head>
<body>
    <form id="myForm" name="myForm" method="post" action="/6june/index.xhtml"
                  enctype="application/x-www-form-urlencoded">
        <input type="hidden" name="myForm" value="myForm" />
        <input type="hidden" name="javax.faces.ViewState" id="javax.faces.ViewState"
value="-6073854252721841133:2030478025710553343" autocomplete="off" />
    </form>
</body>
</html>

So why do I get 2 hidden input fields? And what is that value?

Regards.

http://stackoverflow.com/questions/2910741/what-is-viewstate-in-jsf-and-how-is-it-used will provide you a good start point — Alexandre Lavoie, Jun 08 '13 at 10:23

Adrian Mitev · Accepted Answer · 2013-06-09T19:20:49.300

0

These two hidden fields are added by the renderer of h:form. They're send with each JSF request and are used by JSF to restore its view when postback (form submit) is performed. The value of the javax.faces.ViewState hidden field is also used as CSRF token.

edited Jun 09 '13 at 19:20

answered Jun 08 '13 at 14:32

Adrian Mitev

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You forgot to explain the use of the first hidden input field. – BalusC Jun 08 '13 at 17:12
@BalusC Balus, did not you proivde a very detailed answer to this question? Why is it gone? – Koray Tugay Jun 17 '13 at 17:43

Why JSF adds hidden field in an empty form?

1 Answers1