W3C home > Mailing lists > Public > www-dom@w3.org > April to June 2000

Re: hasAttribute and hasAttributeNS

From: Ray Whitmer <rayw@netscape.com>
Date: Fri, 19 May 2000 14:44:02 -0700
Message-ID: <3925B5A1.D020D9AB@netscape.com>
To: kboone@ebt.com
CC: "DOM (E-mail)" <www-dom@w3.org>
There is no way by calling getAttribute() to determine whether an attribute
exists as an empty string or does not exist.  Both cases return an empty
string, not a null.  getAttribute() != null will never happen in an
implementation that follows the spec properly (I wrote one that didn't, and I
expect others have, but it will have to be fixed...).  You could test
getAttributeNode() every time before getting the attribute and test that for
null, but in a number of implementations, the attribute node never gets
constructed unless it is explicitly referenced, so that causes significant
extra work, just to discover whether the attribute existed or not.

There's no "fixing" getAttribute at this point to make it return null if the
attribute does not exist.  It had to do with some environment or another, I
don't remember which.

Ray Whitmer
ray@xmission.com

"Keith W. Boone" wrote:

> Alright, I'll bite.  Give me a good use case for hasAttribute or
> hasAttributeNS versus getAttribute() != null.  I'm sure it has something to
> do with ancient programming languages like C++ ;-)
>
>         Keith
Received on Friday, 19 May 2000 17:43:57 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 22 June 2012 06:13:47 GMT