[whatwg] HTML 5 : Misconceptions Documented

Kristof Zelechovski giecrilj at stegny.2a.pl
Mon Aug 11 14:53:18 PDT 2008

I have considered inline response.  I have two options: do it by hand (I am
rather busy) and do it for every reply (which makes business people angry).
I am sorry for the inconvenience it causes.  
The item method on a collection when the argument passed is a string that
cannot be coerced to an integer is equivalent to namedItem.  A form element
does not have an intrinsic length property; it can be added as an embedded
named control or by a script.  The elements collection has the intrinsic
length property and it cannot be shadowed.  
My source of information is MSDN, as you have correctly guessed.  If you
have contradictory information on legacy interfaces, please share it with
us.  Note that there is no way we can say it is correct or not; it is an
obsolete interface after all.  However, if it is consistent and all major
implementations support it, there is no reason to think it is false.  
The name 'ell' I used is a name of an embedded control in order to make it
different.  I am not sure about undefined versus null; I rather use Visual
Basic Scripting Edition and I get Nothing (not Empty) for a property an
object does not have.  It may as well be undefined under JavaScript.
See also <http://msdn.microsoft.com/en-us/library/ms536460(VS.85).aspx>.

-----Original Message-----
From: Garrett Smith [mailto:dhtmlkitchen at gmail.com] 
Sent: Monday, August 11, 2008 10:37 PM
To: Kristof Zelechovski
Cc: WHATWG List; Maciej Stachowiak
Subject: Re: [whatwg] HTML 5 : Misconceptions Documented

On 8/11/08, Kristof Zelechovski <giecrilj at stegny.2a.pl> wrote:

Hi Chris,

Thanks for taking the time to respond to some things I was writing
about. I think these are important things that deserve attention, too.

If it's not too much to ask, have you considered inline style response?

I tried to restore posting order, but since you are using Outlook, it
was not effectively possible.

> Neither the expression 'form.elements.$name' nor its expanded form
>  'form.elements["$name"]' is supposed to be defined even if $name is an
>  identifier of an embedded control.  The correct way to address the
>  is 'form.elements("$name")',

Can you cite a reference for this?

AFAIK, this is an IE feature that was copied.

> which is a shorthand notation for
>  'form.elements.item("$name")'.

No, that is wrong. Doubly wrong, I think. The item method retrieves a
node by ordinal index (based on depth-first traversal).

 now if you had wrote:-


That would at least be partially correct. If namedItem is what you
meant, then please supply a reference to back up your claim. I do not
think the claim:

| The correct way to address the control is 'form.elements("$name")'

is true and correct. I think it's an MSIE invention that other
implementations copied.

> These two should not be confused.
>  Therefore, the bug in Opera is not about shadowing the length property
>  about defining the corresponding property at all (in particular,
>  'form.elements.ell' should be null no matter what).

Are you referring to the example I supplied?

>  This could potentially be described in the EcmaScript bindings. But it
>  would be a good idea to explore some edge cases. Particularly, if the
>  case was the order of definition of properties: One such case would be
>  an HTMLCollection with an element named "length". In that case, the
>  readonly "length" property would have to be the actual length of the
>  collection; the value should not be replaced with an element of that
>  name/id.
>  <form><input name="length"></form>
>  document.forms[0].elements.length
>  Opera9: [object HTMLInputElement] <-- BUG
>  FF3: 1
>  Saf3: 1

There was no element in my example with a id or name 'ell', so I would
have to say that form.elements.ell would be undefined, not null.

Where is this - ell - coming from?

>  OTOH, the expression 'form.length' is a perfect equivalent for
>  'form.elements("length")', provided a control with such a name is

form.elements has a readonly property named length.

That property can't be changed (legally) just because a parse  event
found an element named (or id'd) "length".

The length property of a form - form.length - refers to:

>  Have you reported this to Opera technical support?
>  I can see no harm in principle in assigning a value to 'form.length'
>  length is not an intrinsic property the form object.

Chris, I have stated at least twice prior to this email that an
HTMLCollection has a readonly length property.

| length of type unsigned long, readonly
| This attribute specifies the length or size of the list.


>  Chris

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