25_class_context.coffee

class InvoiceForm

  constructor: (@customer) ->

  # Value of "this" might not be the InvoiceForm class 
  calculateTotal: =>
    # do some fancy calculation
    total = 10
    alert "#{this.customer} your total is #{total}" 

$ ->
  invoice = new InvoiceForm("Acme Corporation")
  invoice.calculateTotal()  
  
  $('#btnCalculate').click invoice.calculateTotal 


# If you look at the JavaScript code generated, the 
# code to make sure "this" is what you expect is 
# more complicated than a simple _this.