Dear all,
I am using Odoo 12 and need to print (on the sales order report) a resume of all taxes included on the sales order.
For this, I have tried to create a binary field and pass a dictionary to this field on a computed field.

What I have tried:

1. On the model:

      tax_on_lines = fields.Binary(string="Taxes Lines", compute='_check_taxes')

      def _check_taxes(self):
     for document in self:
         res = {}
         for line in document.order_line:
             tax = line.tax_id
             res.update({tax.name: tax.description})
         document.tax_on_lines = res
         print(document.tax_on_lines)

On the sales order report xml:

     <t t-foreach="doc.tax_on_lines" t-as="tax_on_lines">
         <span t-esc="tax_on_lines"/>
     </t>

This is not working (at least for the xml  - nothing is printed on the report) and I am sure the problem is on the "_check_taxes" method.

When I look to the print() method on the model, I get the following result:

     {'V01': 'Tax description 1', 'V02': 'Tax description 2', 'V05': 'Tax description 5', 'V03': 'Tax description 3'}

So, this ensures that the values are being passed to the "res" dictionary, but in some point the values are not passed to the xml.

Can anyone help me?
Basically I need to print on the sales order report, all taxes included on the sales order. Something like:

      VAT1 - VAT 10%
      VAT2 - VAT 13%
      VAT5 - VAT 23%
      VAT3 - VAT 15%

Thank you all in advance

Best regards

Paulo