[whatwg] Generalized execCommand() alternatives, or standardized selection and range handling

Tim Down timdown at gmail.com
Thu Jun 2 17:07:58 PDT 2011


On 31 May 2011 18:39, Aryeh Gregor <Simetrical+w3c at gmail.com> wrote:
> On Tue, May 31, 2011 at 4:15 AM, Markus Ernst <derernst at gmx.ch> wrote:
>> Anyway, everything we need is actually available in the DOM, except a
>> standardized and simple handling of selections and ranges. (Well, I might be
>> wrong - but looking at the Gecko DOM reference and the MSDN DHTML reference,
>> they show very different approaches to the range and selection objects, and
>> the code of TinyMCE shows lots of browser sniffing.)
>
> That's because browsers' implementations don't follow the specs, or in
> some cases because there weren't specs until the last few months, not
> because there's anything wrong with the spec.  I've implemented all my
> algorithms in pure JavaScript, and there are almost no places where I
> have to work around browser bugs -- given that I only target the
> latest versions of IE/Firefox/Chrome/Opera.  implementation.js is over
> 4000 lines, and I estimate I've needed maybe ten browser-specific
> workarounds, certainly under twenty.  (If you want to support IE<9, of
> course, have fun . . .)

I'm working on this. There was a perverse pleasure in getting to a
workable version of the Range and Selection APIs in IE < 9, and the
commands stuff I've recently built on top based on (a slightly
outdated version of) Aryeh's code has required relatively little
browser-specific code to get bold and italic working. Very rough demo
here (works in IE 6 - 8 as well as sensible browsers):
http://rangy.googlecode.com/svn/branches/1point2/demos/commands.html.

> The only major thing that can't be done in JS is change how ranges
> behave when you mutate the DOM.  Effectively, I work around it by
> using a single Range object to represent the user's selection, and I
> only care how that changes.  This might actually be the way I'll end
> up speccing it too, although it'd be nice if we could preserve ranges
> outside the selection too.

My version passes an array of ranges to be preserved to the command's
various internal methods. Works with multiple selected ranges in
Firefox.

Tim


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