[whatwg] comments on SCRIPT ASYNC and DEFER
whatwg at souders.org
Wed Feb 10 10:28:30 PST 2010
In the current text, it says "must then be fetched". In my suggestion I
say "should not start until after parsing". Saying "should" instead of
"must" leaves the opening for browsers that feel they can fetch
immediately without negatively impacting performance.
On 2/9/2010 6:39 PM, Boris Zbarsky wrote:
> On 2/8/10 4:54 PM, Steve Souders wrote:
>> 4. "If the element has a src attribute, [snip] the specified resource
>> must then be fetched, from the origin of the element's Document."
>> If the script has DEFER, the request should not start until after
>> parsing is finished. Starting it earlier could block other
>> (non-deferred) requests due to a connection limit or limited bandwidth.
> Shouldn't this be left up to a UA? I can see a UA with high enough
> connection limits being willing to use some small number of those
> connections for deferred scripts even before parsing is done. The
> alternative might end up being for the network to be completely idle
> while a bunch of parsing happens followed by a flurry of deferred
> script loading activity....
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