Be able to reference HTML element's reactive properties during cell creation

[rmehlinger]

Currently, a bound attribute on an HTML element cannot reference the reactive properties of the element itself. If, for instance, I want a checkbox to always be enabled if it's already checked, it seems that I have to take the following, slightly complicated approach:

  isChecked = rx.cell()
  R.input {
    type: 'checkbox'
    change: -> isChecked.set($(@).is(':checked'))
    disabled: bind -> not isChecked.get() and someOtherCell.get()
  }

It would be nice to be able to do something like:

  R.input {
    type: 'checkbox'
    disabled: eBind ($elem) -> not $elem.rx('checked').get() and someOtherCell.get()
  }

It would be even nicer if, instead of adding an argument to bind, we could do something like:

  R.input {
    type: 'checkbox'
    disabled: bind => not @.rx('checked').get() and someOtherCell.get()
  }

However, I'm not sure this last is feasible.