The Coffeescript class:

root = exports ? this

class Modal
  constructor: (options = {}) ->
    @options = options
    @id = options.id ? 'modal-dialog-' + Math.round((Math.random() * 1000))
    @dom_id = "##{@id}"
    @onPrimaryButton = options.onPrimaryButton ? ->
    @onSecondaryButton = options.onSecondaryButton ? ->
    @template = options.template ? HandlebarsTemplates['modal'](id: @id)
    @render()

  render: ->
    $('body').append(@template)
    @modal = $(@dom_id)
    _this = this
    @modal.find('.btn-primary').on 'click', ->
      _this.onPrimaryButton(this)
    @modal.find('.btn-secondary').on 'click', ->
      _this.onSecondaryButton(this)

  setButtonText: (primary, secondary) ->
    @modal.find('.btn-primary').html(primary)
    @modal.find('.btn-secondary').html(secondary)

  setTitle: (title) ->
    @modal.find('.title').html(title)

  setBody: (body) ->
    @modal.find('.body').html(body)

  show: ->
    @modal.modal('show')

  hide: ->
    @modal.modal('hide')

root.Modal = Modal

The view (bootstrap 2.3.2):

<div class="modal hide fade" id="{{id}}">
  <div class="modal-header">
    <button aria-hidden="true" class="close" data-dismiss="modal" type="button"> &times;</button>
    <h3 class="title"></h3>
  </div>
  <div class="modal-body body">
  </div>
  <div class="modal-footer">
    <button class="btn btn-secondary" data-dismiss="modal">Cancel</button>
    <button class="btn btn-primary" data-dismiss="modal">Ok</button>
  </div>
</div>

Usage, e.g.:

class Notifications
  constructor:  ->
    @modal = new Modal
      onPrimaryButton: $.proxy(@onItemDelete, this)
      onSecondaryButton: $.proxy(@onItemRead, this)
  onItemDelete: ->
    # do something when primary button was clicked
  onItemRead: ->
    # do something when secondary button was clicked

int choice = NSRunAlertPanel(@"title", @"description", @"DEFAULT", @"ALTERNATE", "OTHER", 8);
    
if(choice == NSAlertDefaultReturn)        

} else if(choice == NSAlertOtherReturn) {

} else if(choice == NSAlertAlternateReturn) {

}