some debug and clearance

data/fields_default.xml

@@ -14,7 +14,7 @@
 self = record  # res.partner.contract
 
 partner = self.partner_id # res.partner
-seller = self.company_id
+seller = self.company_id.partner_id
 
 # Functions
 _ = self._
@@ -164,7 +164,7 @@ action = ctx
 # Aliases
 self = record  # res.partner.contract.annex
 
-seller = self.company_id
+seller = self.company_id.partner_id
 partner = self.partner_id
 
 # Functions

models/res_partner_contract.py

@@ -48,9 +48,9 @@ class PartnerContract(models.Model):  # , IDocument, Extension):
         required=True,
     )
     company_id = fields.Many2one(
-        "res.partner",
+        "res.company",
         string="Company",
-        default=lambda self: self.env.company.partner_id,
+        default=lambda self: self.env.company,
     )
     create_date_ts = fields.Char(default=_get_default_create_date_ts)
     res_model = fields.Char(default=lambda self: self._name)

models/res_partner_contract_annex.py

@@ -30,17 +30,17 @@ class ContractOrderAnnex(models.Model):  # , IDocument, Extension):
         readonly=True,
     )
     company_id = fields.Many2one(
-        "res.partner",
+        comodel_name="res.company",
         related="contract_id.company_id",
     )
     partner_id = fields.Many2one(
-        "res.partner",
+        comodel_name="res.partner",
         related="contract_id.partner_id",
     )
     order_id = fields.Many2one(
-        "sale.order",
-        string="Order",
-        help="This partner's orders which are not used in annexes yet",
+        comodel_name="sale.order",
+        string="Sale order",
+        help="Sale order for this annex.",
         required=True,
     )
     date_conclusion = fields.Date(

models/sale_order.py

@@ -12,25 +12,39 @@ class SaleOrder(models.Model):
         default=45,
     )
     contract_annex_id = fields.Many2one(
-        "res.partner.contract.annex",
+        comodel_name="res.partner.contract.annex",
         string="Contract Annex",
-        readonly=True,
+        compute="get_contract_annex_id",
     )
+    contract_annex_ids = fields.One2many(
+        comodel_name="res.partner.contract.annex",
+        inverse_name="order_id",
+        string="Annex for this Sale order",
+        help="Technical field for binding with contract annex\n"
+        "In form this link showed in 'contract_annex_id' field.",
+    )
+
     # Extend default field for showing payment terms created by this module only.
     payment_term_id = fields.Many2one(
-        "account.payment.term",
+        comodel_name="account.payment.term",
         domain=lambda self: [("id", "in", self._get_payment_terms())],
     )
 
     def _get_payment_terms(self):
-        ref = self.env.ref
-        terms = (
-            ref("{}.{}".format(MODULE_NAME, external_id)).id
+        terms = [
+            self.env.ref("{}.{}".format(MODULE_NAME, external_id)).id
             for external_id in (
                 "payment_term_prepaid",
                 "payment_term_postpayment",
                 "payment_term_partial_2",
                 "payment_term_partial_3",
             )
-        )
-        return list(terms)
+        ]
+        return terms
+
+    @api.onchange("contract_annex_ids")
+    def get_contract_annex_id(self):
+        if self.contract_annex_ids:
+            self.contract_annex_id = self.contract_annex_ids[0].id
+        else:
+            self.contract_annex_id = False

views/sale_order.xml

@@ -10,7 +10,7 @@
             
             <xpath expr="//field[@name='payment_term_id']" position="after">
                 <field name="delivery_time"/>
-                <field name="contract_annex_id"/>
+                <field name="contract_annex_id" readonly="1"/>
             </xpath>
             
         </field>

wizard/res_partner_contract_wizard.py

@@ -10,7 +10,7 @@ from ..utils.docxtpl import get_document_from_values_stream
 _logger = logging.getLogger(__name__)
 
 
-class ContractWizard(models.TransientModel):  # , Extension):
+class ContractWizard(models.TransientModel):
     _name = "res.partner.contract.wizard"
     _inherit = ["client_contracts.utils"]
 
@@ -31,7 +31,6 @@ class ContractWizard(models.TransientModel):  # , Extension):
             "res.partner.contract.annex": "annex",
         }.get(self.active_model, False)
         company_type = self.env.context.get("company_form", False)
-
         document_template_domain = [
             ("template_type", "=", template_type),
             ("company_type", "=", company_type),
@@ -45,14 +44,15 @@ class ContractWizard(models.TransientModel):  # , Extension):
         ],
         string="Target",
         default=_default_target,
+        help="Record of contract or annex entity, from where wizard has been called",
     )
     company_id = fields.Many2one(
-        "res.partner",
+        comodel_name="res.partner",
         string="Company",
         compute="_compute_company_id",
     )
     partner_id = fields.Many2one(
-        "res.partner",
+        comodel_name="res.partner",
         string="Partner",
         compute="_compute_partner_id",
     )
@@ -60,7 +60,7 @@ class ContractWizard(models.TransientModel):  # , Extension):
         string="Document Name", compute="_compute_document_name"
     )
     document_template = fields.Many2one(
-        "res.partner.document.template",
+        comodel_name="res.partner.document.template",
         string="Document Template",
         default=_default_document_template,
         domain=lambda self: self._get_template_domain(),
@@ -78,8 +78,10 @@ class ContractWizard(models.TransientModel):  # , Extension):
 
     @api.depends("target")
     def _compute_company_id(self):
-        if self.target:
-            self.company_id = self.target.company_id
+        if self.target and self.target.company_id:
+            self.company_id = self.target.company_id.id
+        else:
+            self.company_id = self.env.company.id
 
     @api.depends("target")
     def _compute_partner_id(self):
@@ -176,37 +178,7 @@ class ContractWizard(models.TransientModel):  # , Extension):
             )
         ]
 
-        """
-        self.transient_field_ids = [  # one2many
-            (
-                4,
-                self.env["res.partner.contract.field.transient"]
-                .create(
-                    {
-                        "contract_field_id": get_contract_field(field).id,
-                        "value": value,
-                    }
-                )
-                .id,
-                0,
-            )
-            for field, value in sorted(
-                contract_context_values.items(),
-                key=lambda tpl: self.env.ref(
-                    "{}.contract_field_{}".format(MODULE_NAME, tpl[0])
-                ).sequence,
-            )
-        ]
-        self.transient_field_ids_hidden = (
-            self.transient_field_ids - self.transient_field_ids.filtered("visible")
-        )
-        self.transient_field_ids = (
-            self.transient_field_ids - self.transient_field_ids_hidden
-        )
-        """
-
     # Other
-
     def get_docx_contract(self):
         template = self.document_template.attachment_id
         template_path = template._full_path(template.store_fname)
@@ -297,11 +269,14 @@ class ContractWizard(models.TransientModel):  # , Extension):
                 "attachment_ids": [(4, result.id, False)],
             }
         )
-
         return result
 
-    def middleware_fields(self, kv):
-
+    @staticmethod
+    def middleware_fields(kv):
+        """
+        Removes items without values from dictionary.
+        :kv: dict.
+        """
         # Debug False values
         empty = []
         for k, v in list(kv.items()):
@@ -309,7 +284,6 @@ class ContractWizard(models.TransientModel):  # , Extension):
                 empty.append(k)
                 kv.pop(k)
         _logger.debug("Empty fields: {}".format(empty))
-
         return kv
 
     @property

wizard/res_partner_contract_wizard.xml

@@ -10,12 +10,11 @@
 
                 <group string="Template">
                     <field name="document_template"></field>
-                    <field name="target"/>
                 </group>
 
                 <group invisible="1">
                     <!-- Need for generate a document -->
-
+                    <field name="target"/>
                     <field name="partner_id"/>
                     <field name="company_id"/>
                 </group>