Implement element.classList.

element.classList is a DOM feature which allows adding, removing, and
testing for DOM classes on an element without doing string processing
on the space-separated tokens in .className. Add the classList property
and taming for its new list type.

Supporting changes:
* finishArrayLikeClass handles accessor properties on the prototype.
* confidence.amplifying()'s result is constFunc'd rather than def'd
  (not needed here, but spotted as an opportunity).

Fixes <https://code.google.com/p/google-caja/issues/detail?id=1744>.

@r5426

[ihab.awad, 2013-05-28 20:05:52]

The remark in es53-test-scan-guest.js is the only "important" one; all else is
advisory.

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
File src/com/google/caja/plugin/domado.js (right):

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
src/com/google/caja/plugin/domado.js:3463: privates.setT = setTransform;
Are getTransform and setTransform always the same thing throughout Domado?

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
src/com/google/caja/plugin/domado.js:3479: add:
Props.ampMethod(function(privates, ttoken) {
Shouldn't these methods be defined down on the "settable" variant since they are
arguably setters?

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
src/com/google/caja/plugin/domado.js:3496: function(ftoken) {
What are the pros and cons of doing it this way versus iterating using the
feral-side .length and .item()?

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
src/com/google/caja/plugin/domado.js:3514: return
privates.feral.value.replace(/[^ \t\n\r\f]+/g, function(s) {
linewrap nit

https://codereview.appspot.com/9731044/diff/1/tests/com/google/caja/plugin/es...
File tests/com/google/caja/plugin/es53-test-scan-guest.js (right):

https://codereview.appspot.com/9731044/diff/1/tests/com/google/caja/plugin/es...
tests/com/google/caja/plugin/es53-test-scan-guest.js:1431:
argsByProp('addEventListener', argsByProp('removeEventListener',
add vs. remove? confused about this line....

[kpreid2, 2013-05-28 20:20:48]

element.classList is a DOM feature which allows adding, removing, and
testing for DOM classes on an element without doing string processing
on the space-separated tokens in .className. Add the classList property
and taming for its new list type.

Supporting changes:
* finishArrayLikeClass handles accessor properties on the prototype.
* confidence.amplifying()'s result is constFunc'd rather than def'd
  (not needed here, but spotted as an opportunity).

Fixes <https://code.google.com/p/google-caja/issues/detail?id=1744>.

[kpreid2, 2013-05-28 20:24:07]

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
File src/com/google/caja/plugin/domado.js (right):

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
src/com/google/caja/plugin/domado.js:3463: privates.setT = setTransform;
On 2013/05/28 20:05:52, ihab.awad wrote:
> Are getTransform and setTransform always the same thing throughout Domado?

Currently, yes, because we only implement .classList. However, there is at least
one other use of DOMTokenList, per MDN
<https://developer.mozilla.org/en-US/docs/Web/API/DOMTokenList>: .relList, which
is presumably to rel="" as classList is to class="".

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
src/com/google/caja/plugin/domado.js:3479: add:
Props.ampMethod(function(privates, ttoken) {
On 2013/05/28 20:05:52, ihab.awad wrote:
> Shouldn't these methods be defined down on the "settable" variant since
> they are arguably setters?

No. The specified difference between the two types is that DOMSettableTokenList
has a .value property which is an alias for the underlying string value, whereas
DOMTokenList operates strictly on the view of that value as a split list of
tokens.

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
src/com/google/caja/plugin/domado.js:3496: function(ftoken) {
On 2013/05/28 20:05:52, ihab.awad wrote:
> What are the pros and cons of doing it this way versus iterating using the
> feral-side .length and .item()?

The spec says that "A DOMTokenList object must stringify to the value of the
DOMTokenList object's underlying string.", so synthesizing the string out of
iteration over the list would not be appropriate here; for example, it would
discard extra whitespace.

More generally, I observe that a previous version of this change attempted to
implement DOMTokenList and friends from scratch, rather than wrapping the host
types, and it turned out messy. This version tries to be a pure taming: forward
to the underlying operations and do the minimum of rewriting necessary to
preserve the virtualization.

https://codereview.appspot.com/9731044/diff/1/src/com/google/caja/plugin/doma...
src/com/google/caja/plugin/domado.js:3514: return
privates.feral.value.replace(/[^ \t\n\r\f]+/g, function(s) {
On 2013/05/28 20:05:52, ihab.awad wrote:
> linewrap nit

Done.

https://codereview.appspot.com/9731044/diff/1/tests/com/google/caja/plugin/es...
File tests/com/google/caja/plugin/es53-test-scan-guest.js (right):

https://codereview.appspot.com/9731044/diff/1/tests/com/google/caja/plugin/es...
tests/com/google/caja/plugin/es53-test-scan-guest.js:1431:
argsByProp('addEventListener', argsByProp('removeEventListener',
On 2013/05/28 20:05:52, ihab.awad wrote:
> add vs. remove? confused about this line....

Not sure what you're asking.

• argsBy* are chainable: they return their second argument, for convenience when
function have identical signatures.

• I didn't actually change this line: I just reordered it versus item/namedItem
to create a distinct group for the list types below.

[ihab.awad, 2013-05-28 21:38:22]

lgtm++