Rails spinoffs - Apr 2008 - element has no properties error.

Hey all,

I''ve recently started messing around with Prototype again, so I
thought I''d start small and write 5 lines of code that would check if
all fields in a form are filled out. So I thought

document.observe(''dom:loaded'', function() {
	$(''submNewUser'').disable();
	new Form.Observer($(''newUser''), 0.3, function(e, val) {
		if(!$F(''newUsername'').blank() &&
!$F(''email'').blank() && $F(''pword'')
== $F(''checkPassword'')) {
			$(''submNewUser'').enable();
		}
	});
});

would do the trick. But this throws an error:
element has no properties
var method = element.tagName.toLowerCase();

I''m guessing it has something to do with the fact that I''m
checking
the value of an empty field, but I thought you had to use the blank
function for it... So is this a bug or am I missing something stupid?
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Hi,
> I''m guessing it has something to do with the fact that
I''m checking
> the value of an empty field...
That shouldn''t be a problem.  Have you tried breaking up that if
statement into separate checks and then walking through with a
debugger like Firebug to see where exactly the error occurs?  That
could well reveal the problem.  "element has no properties" *usually*
means you''ve gotten a name wrong (case sensitivity?), or -- since
we''re dealing with a form here -- that you''re trying to
retrieve
something by ID that doesn''t have an ID (even though it has a name).
That''s an easy mistake to make.  $F requires an *ID*, not a name:
http://www.prototypejs.org/api/form/element/getValue

Hope this helps,
--
T.J. Crowder
tj / crowder software / com


On Apr 18, 1:29 pm,
"bram.vanders...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org"
<bram.vanders...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> Hey all,
>
> I''ve recently started messing around with Prototype again, so I
> thought I''d start small and write 5 lines of code that would check
if
> all fields in a form are filled out. So I thought
>
> document.observe(''dom:loaded'', function() {
>         $(''submNewUser'').disable();
>         new Form.Observer($(''newUser''), 0.3, function(e,
val) {
>                 if(!$F(''newUsername'').blank() &&
!$F(''email'').blank() && $F(''pword'')
> == $F(''checkPassword'')) {
>                         $(''submNewUser'').enable();
>                 }
>         });
>
> });
>
> would do the trick. But this throws an error:
> element has no properties
> var method = element.tagName.toLowerCase();
>
> I''m guessing it has something to do with the fact that
I''m checking
> the value of an empty field, but I thought you had to use the blank
> function for it... So is this a bug or am I missing something stupid?
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