[ADD] account: compute taxes line on account.move with onchange

Allow the user to set taxes on lines when creating a new account.move.

task: https://www.odoo.com/web#id=33802&view_type=form&model=project.task&action=333&active_id=967&menu_id=4720

addons/account/models/account_move.py

@@ -116,6 +116,52 @@ def _onchange_date(self):
     reverse_date = fields.Date(string='Reversal Date', help='Date of the reverse accounting entry.')
     reverse_entry_id = fields.Many2one('account.move', String="Reverse entry", store=True, readonly=True)
 
+    @api.onchange('line_ids')
+    def _onchange_line_ids(self):
+        '''Compute additional lines corresponding to the taxes set on the line_ids.
+
+        For example, add a line with 1000 debit and 15% tax, this onchange will add a new
+        line with 150 debit.
+        '''
+        # Retrieve the existing tax lines and drop them.
+        self.line_ids -= self.line_ids.filtered(lambda l: l.tax_line_id)
+
+        for line in self.line_ids:
+            if not line.tax_ids:
+                continue
+            balance = line.debit - line.credit
+            taxes_vals = line.tax_ids.compute_all(balance,
+                currency=line.currency_id, product=line.product_id, partner=line.partner_id)
+            bank_id = line.statement_id
+
+            # Create a new line for each tax.
+            for tax_vals in taxes_vals['taxes']:
+                name = line.name and line.name + ' ' + line['name'] or tax_vals['name']
+                tax = self.env['account.tax'].browse([tax_vals['id']])
+                line_vals = {
+                    'account_id': tax.account_id.id,
+                    'name': name,
+                    'journal_id': line.journal_id.id,
+                    'company_id': line.journal_id.company_id.id,
+                    'tax_line_id': tax_vals['id'],
+                    'partner_id': line.partner_id.id,
+                    'statement_id': line.statement_id.id,
+                    'debit': tax_vals['amount'] > 0 and tax_vals['amount'] or 0.0,
+                    'credit': tax_vals['amount'] < 0 and -tax_vals['amount'] or 0.0,
+                    'analytic_account_id': line.analytic_account_id.id if tax.analytic else False,
+                    'date': line.date,
+                    'move_id': self.id,
+                }
+                if bank_id:
+                    context = {'date': line.date}
+                    from_currency_id = bank_id.company_id.currency_id
+                    to_currency_id = bank_id.currency_id
+                    amount_currency = from_currency_id.with_context(context).compute(
+                        tax_vals['amount'], currency=to_currency_id, round=True)
+                    line_vals['currency_id'] = to_currency_id.id
+                    line_vals['amount_currency'] = amount_currency
+                self.env['account.move.line'].new(line_vals)
+
     @api.model
     def fields_view_get(self, view_id=None, view_type='form', toolbar=False, submenu=False):
         res = super(AccountMove, self).fields_view_get(

addons/account/views/account_view.xml

@@ -1468,6 +1468,7 @@
                             <field name="line_ids" widget="one2many_list"
                               context="{'line_ids': line_ids, 'journal_id': journal_id }">
                                 <tree editable="bottom" string="Journal Items">
+                                    <field name="tax_line_id" invisible="1"/>
                                     <field name="account_id" domain="[('company_id', '=', parent.company_id), ('deprecated', '=', False)]"/>
                                     <field name="partner_id"
                                         domain="['|', ('parent_id', '=', False), ('is_company', '=', True)]"/>
@@ -1480,6 +1481,8 @@
                                     <field name="currency_id" options="{'no_create': True}" groups="base.group_multi_currency"/>
                                     <field name="debit" sum="Total Debit"/>
                                     <field name="credit" sum="Total Credit"/>
+                                    <field name="tax_ids" string="Tax Applied" widget="many2many_tags"
+                                           options="{'no_create': True}"/>
                                     <field name="date_maturity" required="0" invisible="context.get('view_no_maturity', False)"/>
                                 </tree>
                             </field>