I want to set a tax for each lines of an invoice.

can you elaborate the exact scenario ?

Regards,
Parthiv

Thanks for your prompt reply...

Well when I go to Sales module---> Sales Orders----> Click on New
          1. select the customer
          2. click on Advance Invoice
          3. select Advance Product/Amount
          4. Click on Create Invoice
          5. Prompt you a message "You invoice has been successfully created! ----Close or Open Invoice
         6. Click on "Open Invoice"
         7. Now you create several invoices - suppose you have 2 records in the invoice line as shown below:

        Product Qty Unit Price Discount Subtotal
        xxxxx 1 100 0 100
        yyyy 1 200 0 200

       8 Now I want to add a column Line Vat Amount with the actual vat rate from table account.tax field amount as shown below :
     Product Qty Unit Price Discount Line Vat Amount Subtotal
        xxxxx 1 100 0 15 115
        yyyy 1 200 0 30 230

     I have selected tax rate 15%

Should you need any other info please let me know.
Please help.

You can add one function field in invoice.line object which will compute line wise tax.
you can reuse code of account.invoice to compute line wise tax in new function field.

Actually I wrote a class that inherit the account.invoice.line class and created a function field. But it doesn't work. It gives following error :

ProgrammingError: column account_invoice_line.vatt does not exist
LINE 1: ...voice_line.uos_id,account_invoice_line.account_id,account_in...

Here's .py file

import decimal_precision as dp
from osv import osv,fields

class account_invoice_line(osv.osv):

 def _amount_tax_linee(self,cr,uid,ids,name,args,context=None):
  res = {}
  tax_obj = self.pool.get('account.tax')
  for line in self.browse(cr,uid,ids):
   price = line.price_unit * (1-(line.discount or 0.0)/100.0)
   taxes = tax_obj.compute_all(cr, uid, line.invoice_line_tax_id, price, line.quantity, product=line.product_id,address_id=line.invoice_id.address_invoice_id,partner=line.invoice_id.partner_id)
   for tax in tax_obj.compute_all(cr, uid, line.invoice_line_tax_id, (line.price_unit* (1-(line.discount or 0.0)/100.0)), line.quantity, line.invoice_id.address_invoice_id,line.product_id,line.invoice_id.partner_id)['taxes']:
    val = {}
    val['amount'] = tax['amount']
    res[line.id] = val['amount']
  return res

 _name="account.invoice.line"
 _inherit="account.invoice.line"
 _columns = {
  'vatt' : fields.function(_amount_tax_linee, method=True, string='Line Vat', type="float",
            digits_compute= dp.get_precision('Account'), store=True),

 }

account_invoice_line()

Kindly advise where am I wrong.

Best regards
Angel

Complete error message

Environment Information :
System : Windows-Vista-6.1.7600
OS Name : nt
Operating System Release : Vista
Operating System Version : 6.1.7600
Operating System Architecture : 32bit
Operating System Locale : en_GB.cp1252
Python Version : 2.5.2
OpenERP-Client Version : 6.0.1
Last revision No. & ID :Bazaar Package not Found !Traceback (most recent call last):
  File "netsvc.pyo", line 489, in dispatch
  File "service\web_services.pyo", line 599, in dispatch
  File "osv\osv.pyo", line 122, in wrapper
  File "osv\osv.pyo", line 176, in execute
  File "osv\osv.pyo", line 167, in execute_cr
  File "osv\orm.pyo", line 2921, in read
  File "osv\orm.pyo", line 3041, in _read_flat
  File "osv\fields.pyo", line 793, in get
  File "C:\Program Files\OpenERP 6.0\Server\addons\account_invoice_layout\account_invoice_layout.py", line 136, in _fnct
  File "osv\orm.pyo", line 285, in __getattr__
  File "osv\orm.pyo", line 205, in __getitem__
  File "osv\orm.pyo", line 2921, in read
  File "osv\orm.pyo", line 2980, in _read_flat
  File "sql_db.pyo", line 78, in wrapper
  File "sql_db.pyo", line 131, in execute
ProgrammingError: column account_invoice_line.vatt does not exist
LINE 1: ...voice_line.uos_id,account_invoice_line.account_id,account_in...

On Wednesday 16 February 2011, you wrote:
> Question #144173 on OpenERP Addons changed:
> https://answers.launchpad.net/openobject-addons/+question/144173

> ProgrammingError: column account_invoice_line.vatt does not exist
> LINE 1: ...voice_line.uos_id,account_invoice_line.account_id,account_in...

did you put a double 't' there? "vatt" ??

Thanks Husen Daudi, that solved my question.