Create Sample Tax Extension

Create a sample tax extension as follows:

• on post event for financial_item (create, edit, delete), implement code to handle the tax implementations of the financial_item by doing an appropriate thing (create, edit or delete) with a matched financial_item, and also updating the contribution total as appropriate.
  • the extension will assume that all items using a revenue financial account marked as taxable are taxable
  • the financial account for the tax will not be taxable in this simple example extension
  • name the tax HST, and use 0.13 as the amount
• UI: change the offline New Membership form so that it displays price set amounts as follows (see image):
  • under membership Amount field, add Taxes (frozen) and Total Amount (frozen)
  • use the Name of the Financial Account that is used for the tax as the label of the field
• add an additional record to the civicrm_financial_trxn table transferring the HST amount from the Expenses HST account to an Accounts Payable HST account representing the amount owed to the government
• on changes and reversals, ensure that any transfer into or out of the HST expense account is matched by an additional entry in civicrm_financial_trxn making equivalent changes to the Accounts Payable HST account (ie change reducing tax results in reduction in expense and reduction in amounts owed to government)