There might be a number of different places you may want to do this. It is left up to you to figure out where, I can however, give you a starting point.
Invoiceplane, and Codeignitor generally follows the MVC (Model-Controller-View) design pattern, so in general
- A request from a View is handled by a Controller
- The controller processes the request, then calls upon the Model to perform the business processes.
- The Model passes control back to the Controller, who send the output to the View
So, say you want to save the values on the database
=> for invoices, you would look in application/modules/invoices/models/Mdl_invoices.php
=> for quotes, you would look in application/modules/quotes/models/Mdl_quotes.php
Get the picture?
So, in the case of invoices, in the model you would find a function to create a new invoice,
public function create($db_array = null, $include_invoice_tax_rates = true)
You can either change the values in the Model, or find each place that calls that function (for example in a controller), and change it before calling the function. It is no
t so straighforward, however. Remember that you have to display the value correctly in the invoice before saving it - you cannot show one value and save another. You would therefore want to adjust the rounding when adding a new item on the invoice and calculating the rounded up values.