Chainable attributes for class + id DOM builder DSL

[Christopher Keele]

Running with the principle of least surprise, I'd expect the following to work:

$document.ready? do
  DOM do
    canvas.game!.lol.wut width: 500, height: 500
  end.append_to $document.body
end

However, this generates

<canvas id="game" class="lol wut">{"width"=>500, "height"=>500}</canvas>

My reasoning here is when constructing DOM elements, especially divs, frequently the id and classes are the primary concern, and attributes second. (This is implied by id and class attributes being special-cased by the DSL.) Years of HAML may have reinforced this preference, but I find it to be quite pleasantly readable.

Contrast with:

$document.ready? do
  DOM do
    canvas(width: 500, height: 500).game!.lol.wut
  end.append_to $document.body
end

which is what I must do at present.

I'm working on a PR, but I'm having trouble running the test suite, so I'm fumbling in the dark a little.

[Christopher Keele]

Looks like this belongs in Paggio. Moving there.