[Seaside] tutorial1: form submit method

[Nevin Pratt]

OK, looking at the following code from the seaside tutorial1:

<form action="@convert">
<input name="@amount" type="text" size="4">

<input type="radio" name="@conversion" value="13.760300">ATS
<input type="radio" name="@conversion" value="40.3399900">BEF
<input type="radio" name="@conversion" value="1.955830">DEM
<input type="radio" name="@conversion" value="166.386000">ESP
<input type="radio" name="@conversion" value="6.559570">FRF

<input type="submit" value="Convert">
</form>
 = <b>42.0 EUR</b>


The above is the string for the #html method for the SeasideTutorial 
class from the tutorial.  When that class/app is viewed in the browser, 
it of course has a button that, when pressed, invokes the #convert 
instance method in the SeasideTutorial class.  Just as the tutorial says 
it should.

OK, good enough.

But, what exactly happens if there was *no* action attribute specified 
in the form tag above, and it is therefore just <form> rather than <form 
action="@convert">?  What method gets invoked then?

When I try to test this particular variation (i.e., no action attribute 
at all), then press the input button in the browser, nothing happens *at 
all* (that I can tell).

I've tried some judiciously placed 'self halt' statements in the Seaside 
code hoping to intercept it trying to do something, but so far I've come 
up empty.

So, what exactly happens when there is no action attribute specified for 
the form tag?

The reason I am asking is because some server-to-server communication 
conventions will try to do just that.  For example, if you use the IPN 
(Instant Payment Notification) server-to-server feature of PayPal, then 
the PayPal server will try to invoke a URL that you have specified, with 
a form filled with a bunch of hidden input fields.  In other words, 
PayPal will try to POST something very similar to the above html, but 
without an action attribute specified.  I need to know how to intercept 
such a situation from within Seaside so that I can look at the hidden 
fields PayPal is trying to send me.

Nevin