Change Pool into a Singleton

account.py

@@ -6,6 +6,7 @@ from trytond.model import ModelView, ModelSQL, fields
 from trytond.wizard import Wizard
 from trytond.pyson import Equal, Eval, Not, PYSONEncoder
 from trytond.transaction import Transaction
+from trytond.pool import Pool
 
 
 class Account(ModelSQL, ModelView):
@@ -78,8 +79,8 @@ class Account(ModelSQL, ModelView):
         return Transaction().context.get('company') or False
 
     def default_currency(self):
-        company_obj = self.pool.get('company.company')
-        currency_obj = self.pool.get('currency.currency')
+        company_obj = Pool().get('company.company')
+        currency_obj = Pool().get('currency.currency')
         if Transaction().context.get('company'):
             company = company_obj.browse(Transaction().context['company'])
             return company.currency.id
@@ -98,7 +99,7 @@ class Account(ModelSQL, ModelView):
         return False
 
     def on_change_with_currency_digits(self, vals):
-        currency_obj = self.pool.get('currency.currency')
+        currency_obj = Pool().get('currency.currency')
         if vals.get('currency'):
             currency = currency_obj.browse(vals['currency'])
             return currency.digits
@@ -112,8 +113,8 @@ class Account(ModelSQL, ModelView):
 
     def get_balance(self, ids, name):
         res = {}
-        line_obj = self.pool.get('analytic_account.line')
-        currency_obj = self.pool.get('currency.currency')
+        line_obj = Pool().get('analytic_account.line')
+        currency_obj = Pool().get('currency.currency')
         cursor = Transaction().cursor
 
         child_ids = self.search([('parent', 'child_of', ids)])
@@ -178,8 +179,8 @@ class Account(ModelSQL, ModelView):
 
     def get_credit_debit(self, ids, name):
         res = {}
-        line_obj = self.pool.get('analytic_account.line')
-        currency_obj = self.pool.get('currency.currency')
+        line_obj = Pool().get('analytic_account.line')
+        currency_obj = Pool().get('currency.currency')
         cursor = Transaction().cursor
 
         if name not in ('credit', 'debit'):
@@ -326,8 +327,8 @@ class OpenChartAccount(Wizard):
     }
 
     def _action_open_chart(self, data):
-        model_data_obj = self.pool.get('ir.model.data')
-        act_window_obj = self.pool.get('ir.action.act_window')
+        model_data_obj = Pool().get('ir.model.data')
+        act_window_obj = Pool().get('ir.action.act_window')
         act_window_id = model_data_obj.get_id('analytic_account',
                 'act_account_tree2')
         res = act_window_obj.read(act_window_id)
@@ -362,7 +363,7 @@ class AccountSelection(ModelSQL, ModelView):
 
     def check_root(self, ids):
         "Check Root"
-        account_obj = self.pool.get('analytic_account.account')
+        account_obj = Pool().get('analytic_account.account')
 
         root_account_ids = account_obj.search([
             ('parent', '=', False),

line.py

@@ -6,6 +6,7 @@ from trytond.wizard import Wizard
 from trytond.backend import TableHandler
 from trytond.pyson import Eval, PYSONEncoder
 from trytond.transaction import Transaction
+from trytond.pool import Pool
 
 
 class Line(ModelSQL, ModelView):
@@ -58,14 +59,14 @@ class Line(ModelSQL, ModelView):
         table.not_null_action('currency', action='remove')
 
     def default_date(self):
-        date_obj = self.pool.get('ir.date')
+        date_obj = Pool().get('ir.date')
         return date_obj.today()
 
     def default_active(self):
         return True
 
     def on_change_with_currency(self, vals):
-        move_line_obj = self.pool.get('account.move.line')
+        move_line_obj = Pool().get('account.move.line')
         if vals.get('move_line'):
             move_line = move_line_obj.browse(vals['move_line'])
             return move_line.account.company.currency.id
@@ -78,7 +79,7 @@ class Line(ModelSQL, ModelView):
         return res
 
     def on_change_with_currency_digits(self, vals):
-        move_line_obj = self.pool.get('account.move.line')
+        move_line_obj = Pool().get('account.move.line')
         if vals.get('move_line'):
             move_line = move_line_obj.browse(vals['move_line'])
             return move_line.account.company.currency.digits
@@ -141,8 +142,8 @@ class OpenAccount(Wizard):
     }
 
     def _action_open_account(self, data):
-        model_data_obj = self.pool.get('ir.model.data')
-        act_window_obj = self.pool.get('ir.action.act_window')
+        model_data_obj = Pool().get('ir.model.data')
+        act_window_obj = Pool().get('ir.action.act_window')
 
         act_window_id = model_data_obj.get_id('analytic_account',
                 'act_line_form')