add contexual field to invoice form and copy value from sales if available

sale_order_contextual/__manifest__.py

@@ -2,11 +2,12 @@
     'name': 'Sale Order Contextual Note',
     'version': '16.0.1.0.0',
     'category': 'Sales',
-    'summary': 'Adds a contextual note field to sale orders',
+    'summary': 'Adds a contextual note field to sale orders and invoices',
     'author': 'DomusLavila',
-    'depends': ['sale_management'],
+    'depends': ['sale_management', 'account'],
     'data': [
         'views/sale_order_contextual_view.xml',
+        'views/account_move_form.xml',
     ],
     'installable': True,
     'auto_install': False,

sale_order_contextual/models/__init__.py

@@ -1 +1,2 @@
 from . import sale_order_contextual
+from . import account_move

sale_order_contextual/models/account_move.py

@@ -0,0 +1,9 @@
+from odoo import fields, models
+
+
+class AccountMoveContextual(models.Model):
+    _inherit = 'account.move'
+
+    contextual_note = fields.Text(
+        string='Contextuele opmerking',
+    )

sale_order_contextual/models/sale_order_contextual.py

@@ -7,3 +7,9 @@ class SaleOrderContextual(models.Model):
     contextual_note = fields.Text(
         string='Contextuele opmerking',
     )
+
+    def _prepare_invoice(self):
+        vals = super()._prepare_invoice()
+        if self.contextual_note:
+            vals['contextual_note'] = self.contextual_note
+        return vals

sale_order_contextual/views/account_move_form.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+    <record id="account_move_contextual_note_form" model="ir.ui.view">
+        <field name="name">account.move.contextual.note.form</field>
+        <field name="model">account.move</field>
+        <field name="inherit_id" ref="account.view_move_form"/>
+        <field name="arch" type="xml">
+            <xpath expr="//notebook" position="before">
+                <separator string="Contextual"/>
+                <group>
+                    <field name="contextual_note" string="Note" colspan="2"/>
+                </group>
+            </xpath>
+        </field>
+    </record>
+</odoo>

sale_order_contextual/views/sale_order_contextual_view.xml

@@ -5,10 +5,11 @@
         <field name="model">sale.order</field>
         <field name="inherit_id" ref="sale.view_order_form"/>
         <field name="arch" type="xml">
-            <xpath expr="//notebook" position="inside">
-                <page string="Contextual" name="contextual_note_page">
-                    <field name="contextual_note" nolabel="1"/>
-                </page>
+            <xpath expr="//group[@name='sale_header']" position="after">
+                <separator string="Contextual"/>
+                <group>
+                    <field name="contextual_note" string="Note" colspan="2"/>
+                </group>
             </xpath>
         </field>
     </record>