       # console.log 'found scopes', scopes
 
       constraintBinding = @constraints[name]
-      bindings = constraintBinding.bindings or= {}
+      bindings = constraintBinding.bindings ?= {}
 
       for scope in scopes
         bindexpression = scope.binding


  class Node extends Module
    @include Events

    constructor: (el, attributes = {}) ->
      @types = attributes.types ? {}


    init: (attributes) ->
      for name, value of attributes
        if name.indexOf('on') == 0
          name = name.substr(2)
          # console.log('binding to event expression', name, value, @)
          @bind(name, @eventCallback(name, value, @))
        else
          @setAttribute(name, value)
      @bindConstraints() if @constraints
      @trigger('init', @) if @events?['init']

    set_parent: (parent) ->
      # console.log 'set_parent', parent, @
