[whatwg] Questions about script attributes in HTML5
Ian Hickson
ian at hixie.ch
Tue Aug 24 15:20:39 PDT 2010
On Thu, 29 Jul 2010, zhao Matt wrote:
>
> Quote:
> "The async and defer attributes are boolean attributes that indicate how the
> script should be executed."..."The defer attribute may be specified even if
> the async attribute is specified"
> Do it mean 'async' is equivalent to 'defer'? (namely, are the two attributes
> interchangeable?)
No.
> Quote:
> "The defer and async attributes must not be specified if the src attribute
> is not present."
> Do it mean "if the src attribute is not present, the defer and async
> attributes can be not used" ? (English is not my native language, :) )
Yes.
> However, I saw the defer attribute can work on both in-line and external
> scripts . In short, when the src attribute is not present, the defer
> attributes can be used.
We disallow that because there are some serious compatibility issues
regarding document.write() and innerHTML if you implement defer="" on
inline scripts, so it was easier to just make it not work.
--
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
More information about the whatwg
mailing list