- From: Elliotte Harold <elharo@metalab.unc.edu>
- Date: Thu, 01 Dec 2005 07:59:47 -0500
- To: Maciej Stachowiak <mjs@apple.com>
- CC: DOM mailing list <www-dom@w3.org>, andersca@mac.com
Maciej Stachowiak wrote: > Both "" and null are reasonable things to return for a nonexistent > attribute, there is no deep principle at stake here. I disagree. I think there's an obvious difference between null and "". It allows one to distinguish between <img alt="" /> and <img />. This has semantic value. The former indicates that an explicit choice was made not to provide an alt attribute, and that therefore the image is purely presentational. The latter indicates that the author didn't consider the alt text to provide. The former is the empty string. The latter is null. There are many other cases one could construct where the difference between having an attribute with an empty string value and not having an attribute at all is significant. Of course, it would be possible to use hasAttribute to make this distinction if necessary. is it necessary? The issue of languages without any nulls is compelling, provided examples of such languages can be provided. Off the top of my head the only one I can think of is XSLT, but there's no DOM implementation for XSLT. Which languages someone might actually want to use inside a browser do not have a null value? -- Elliotte Rusty Harold elharo@metalab.unc.edu XML in a Nutshell 3rd Edition Just Published! http://www.cafeconleche.org/books/xian3/ http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim
Received on Thursday, 1 December 2005 13:00:05 UTC