RFC: Add common named params to all Element constructors

RFC: Add common named params to all Element constructors

This is one of the options we discussed to streamline element construction.

E.g., the following (fairly common pattern):

new Element.html('<div class="back-arrow button"></div>');

becomes:

new DivElement(classes: ['back-arrow', 'button']);

See the test for a few more examples.  Improvement?

[sethladd, 2012-06-14 17:25:50]

how about adding a Map attrs as optional catch-all map of other attributes? This
is the escape hatch so we don't need to be totally complete.

var input = new InputElement(id: 'foo', attrs: {'name': foo', 'disabled':true});

Also, name is pretty common for input elements, you might want that as a first
class named arg.

[sethladd, 2012-06-14 17:27:45]

VideoElement should probably have a src named arg.

Where is AudioElement?

[sra1, 2012-06-14 18:02:59]

Our plan of record here is to use method cascades.

I have made a comment on Issue 3640.
http://code.google.com/p/dart/issues/detail?id=3640

Lets take the debate there, and restrict the commentary on the CL to issues of
the code.