CSPP51038
Homework 2
Due: July 28

We will continue with our mortgage application by writing a second
code (service) that takes the xml output of the first code as input
and returns a new xml file. The second code will be written entirely
in XSLT (standalone is fine). It will remove some nodes, add others,
and do a few calculations to put in the output.  You should be expert
in XSLT after writing this!

What your xslt will do:
 - Input: 
    * A valid Mortgage_payments .xml file
    * begin month
    * name of borrower
    * currency 

- Output:
    *transformed .xml file

- Transformed .xml file will have the following elements with valid data:
   * name of the borrower 
   * loan initiation date
   * payment amount and due date with a boolean "made" attribute (ie true if payment has been made)
   * remaining balance, as in input .xml
   * principle paid
   * interest paid
   * currency -- an enumerated type defined in a separate schema and namespace

   Any field not mentioned above that is in the input .xml should be removed and should not appear in output .xml

   Your XSLT program must be able to convert all figures from the input currency ($$) to the specified target
   currency.

- perform validation of output against schema (this can be done as a separte step and does not have to be invoked from XSL program)


You are free to define any reasonable schema that contains the elements/concepts specified above (I don't
want to overprescribe). A reasonable example might be:

<?xml version="1.0" encoding="UTF-8"?>

<loan begin_date="2002-09-24" currency="USD">
    <borrower>Andrew Siegel</borrower>
    <amount>500000.00</amount>
    <payment made="false" due_date="2002-10-24">
        <amount>2200.50</amount>
        <principle_paid>500.00</principle_paid>
        <interest_paid>1700.00</interest_paid>
        <remaining_balance>499950.00</remaining_balance>   
    </payment>
    
    <payment made="false" due_date="2002-11-24" currency="USD">
        <amount>2200.50</amount>
        <principle_paid>502.00</principle_paid>
        <interest_paid>1698.50</interest_paid>
        <remaining_balance>...</remaining_balance>   
    </payment>
    .
    .
    .
</loan>