Add include_347 field in tax template to update this field throw an xml (347.xml) on tax tempalte and after when update account char, update it on tax

__init__.py

@@ -18,6 +18,7 @@ def register():
         invoice.Reasign347RecordStart,
         invoice.Reasign347RecordEnd,
         invoice.InvoiceTax,
+        tax.TaxTemplate,
         tax.Tax,
         module='aeat_347', type_='model')
     Pool.register(

tax.py

@@ -9,7 +9,25 @@ from trytond.transaction import Transaction
 from sql.operators import In
 from .aeat import OPERATION_KEY
 
-__all__ = ['Tax']
+__all__ = ['TaxTemplate', 'Tax']
+
+
+class TaxTemplate:
+    __metaclass__ = PoolMeta
+    __name__ = 'account.tax.template'
+
+    include_347 = fields.Boolean('Include 347')
+
+    @staticmethod
+    def default_include_347():
+        return True
+
+    def _get_tax_value(self, tax=None):
+        res = super(TaxTemplate, self)._get_tax_value(tax)
+
+        if not tax or tax.include_347 != self.include_347:
+            res['include_347'] = self.include_347
+        return res
 
 
 class Tax:

tryton.cfg

@@ -8,3 +8,4 @@ xml:
     invoice.xml
     party.xml
     tax.xml
+    347.xml