Re: Mutation events replacement

On 9/07/11 1:12 AM, Ryosuke Niwa wrote:
> On Fri, Jul 8, 2011 at 5:21 AM, Sean Hogan <shogun70@westnet.com.au 
> <mailto:shogun70@westnet.com.au>> wrote:
>
>     - MathJax (http://mathjax.org) is a JS lib that facilitates
>     putting math onto the web by converting LaTeX or MathML markup in
>     a page to HTML. By default MathJax triggers off the onload event
>     to run this conversion on the page. When content containing math
>     is dynamically added to the page, MathJax must be called manually
>     to convert the new content. A DOM insertion listener could
>     potentially be used to handle this conversion automatically.
>
>     - A similar use-case is element augmentation too complex for CSS
>     :before and :after
>
>     - ARIA support in JS libs currently involves updating
>     aria-attributes to be appropriate to behavior the lib is
>     implementing. Attribute mutation listeners would allow an inverse
>     approach - behaviors being triggered off changes to aria-attributes.
>
>     - DOM insertion and removal listeners could facilitate the
>     implementation of automatically updating Table-of-* (Headings /
>     Images / etc).
>
>
> It seems like all 3 use cases here can be implemented by observers 
> that are called AFTER the fact, and do not requiere any events or 
> callbacks before mutation.
>


I agree, but it's just a list of the top of my head - I was merely 
trying to assist with the request for use-cases.

An obvious advantage of callbacks that occur BEFORE mutation is that 
they can be used to implement post-mutation notifications. The reverse 
is impossible.