feat: Adapt UOM selection and validation to Odoo 19's _has_common_reference method, update module version, and correct the window action's group attribute.

__manifest__.py

@@ -1,6 +1,6 @@
 {
     'name': 'Product UOM Change',
-    'version': '18.0.1.0.0',
+    'version': '19.0.1.0.0',
     'summary': 'Allow changing Product UOM even if stock moves exist',
     'description': """
         This module adds a wizard to allow changing the Unit of Measure (UOM) of a product

wizard/change_uom.py

@@ -7,23 +7,66 @@ class ProductUomChangeWizard(models.TransientModel):
 
     product_tmpl_id = fields.Many2one('product.template', string='Product', required=True, readonly=True)
     current_uom_id = fields.Many2one('uom.uom', related='product_tmpl_id.uom_id', string='Current UOM', readonly=True)
-    uom_category_id = fields.Many2one('uom.category', related='product_tmpl_id.uom_id.category_id', readonly=True)
+    allowed_uom_ids = fields.Many2many('uom.uom', string='Allowed UOMs', compute='_compute_allowed_uom_ids')
     new_uom_id = fields.Many2one('uom.uom', string='New UOM', required=True)
     new_uom_po_id = fields.Many2one('uom.uom', string='New Purchase UOM')
 
+    @api.depends('product_tmpl_id.uom_id')
+    def _compute_allowed_uom_ids(self):
+        for record in self:
+            if record.product_tmpl_id.uom_id:
+                # Find all UOMs that share the same root reference as the current UOM
+                # uom.uom model now uses _has_common_reference logic, but simpler to search by root category if possible.
+                # Since category_id is gone, we can group by root UoM if that concept exists, or rely on _has_common_reference.
+                # However, for a domain, we need a list of IDs.
+                # We can iterate all UOMs and check _has_common_reference, OR traverse up to the root and back down.
+                # Looking at uom_uom.py: _order = 'sequence, relative_uom_id, id'.
+                # fields: relative_uom_id (Reference Unit), related_uom_ids (Related UoMs).
+                # To get all in "category", we need to find the root.
+                
+                # Let's traverse up to find the root.
+                uom = record.product_tmpl_id.uom_id
+                while uom.relative_uom_id:
+                    uom = uom.relative_uom_id
+                
+                # uom is now the root. Now find all descendants.
+                # A recursive search or using parent_path would be ideal if available/indexed.
+                # uom.uom has parent_path.
+                # parent_path structure: "root_id/child_id/..."
+                # So all UOMs in same category start with same root_id in parent_path.
+                root_id = uom.id
+                domain = [('parent_path', '=like', f'{root_id}/%')]
+                # Also include the root itself if it doesn't match the like pattern (which it usually doesn't as it is just "id/")
+                # Wait, parent_path is updated by standard valid Parent/Child implementation.
+                # Actually, simpler: search for uoms where root is the same.
+                # But we don't have a stored 'root_id'.
+                # Let's use the fact that we have the root uom 'uom'.
+                # We can search for all uoms that have this root as ancestor?
+                # Actually, standard Odoo usually just does `uom.search([])` and filters in python if the set is small, 
+                # but UOMs can be many.
+                # Let's look at uom_uom.py again. 
+                # It has `_has_common_reference`.
+                
+                # A safer approach for now: Get all UOMs and filter. UOM table is usually small < 100.
+                all_uoms = self.env['uom.uom'].search([])
+                allowed = all_uoms.filtered(lambda u: u._has_common_reference(record.product_tmpl_id.uom_id))
+                record.allowed_uom_ids = allowed
+            else:
+                record.allowed_uom_ids = False
+
     @api.model
     def default_get(self, fields):
         res = super(ProductUomChangeWizard, self).default_get(fields)
-        if self._context.get('active_model') == 'product.template' and self._context.get('active_id'):
+        if self.env.context.get('active_model') == 'product.template' and self.env.context.get('active_id'):
-            res['product_tmpl_id'] = self._context['active_id']
+            res['product_tmpl_id'] = self.env.context['active_id']
-        elif self._context.get('active_model') == 'product.product' and self._context.get('active_id'):
+        elif self.env.context.get('active_model') == 'product.product' and self.env.context.get('active_id'):
-            product = self.env['product.product'].browse(self._context['active_id'])
+            product = self.env['product.product'].browse(self.env.context['active_id'])
             res['product_tmpl_id'] = product.product_tmpl_id.id
         return res
 
     def action_change_uom(self):
         self.ensure_one()
-        if self.new_uom_id.category_id != self.product_tmpl_id.uom_id.category_id:
+        if not self.new_uom_id._has_common_reference(self.product_tmpl_id.uom_id):
             raise UserError(_("New UOM must be in the same category as the current UOM."))
 
         # Update UOM via SQL to bypass the constraint check in product.template write
@@ -31,7 +74,7 @@ class ProductUomChangeWizard(models.TransientModel):
         
         # Also update Purchase UOM if specified
         if self.new_uom_po_id:
-            if self.new_uom_po_id.category_id != self.product_tmpl_id.uom_po_id.category_id:
+            if not self.new_uom_po_id._has_common_reference(self.product_tmpl_id.uom_po_id):
                  raise UserError(_("New Purchase UOM must be in the same category as the current Purchase UOM."))
             self.env.cr.execute("UPDATE product_template SET uom_po_id = %s WHERE id = %s", (self.new_uom_po_id.id, self.product_tmpl_id.id))
 

wizard/change_uom_views.xml

@@ -8,9 +8,9 @@
                 <group>
                     <field name="product_tmpl_id"/>
                     <field name="current_uom_id"/>
-                    <field name="uom_category_id" invisible="1"/>
+                    <field name="allowed_uom_ids" invisible="1"/>
-                    <field name="new_uom_id" domain="[('category_id', '=', uom_category_id), ('id', '!=', current_uom_id)]"/>
+                    <field name="new_uom_id" domain="[('id', 'in', allowed_uom_ids), ('id', '!=', current_uom_id)]"/>
-                    <field name="new_uom_po_id" domain="[('category_id', '=', uom_category_id)]"/>
+                    <field name="new_uom_po_id" domain="[('id', 'in', allowed_uom_ids)]"/>
                 </group>
                 <footer>
                     <button name="action_change_uom" string="Change UOM" type="object" class="btn-primary" data-hotkey="q"/>
@@ -27,6 +27,6 @@
         <field name="target">new</field>
         <field name="binding_model_id" ref="product.model_product_template"/>
         <field name="binding_view_types">form</field>
-        <field name="groups_id" eval="[(4, ref('base.group_system'))]"/>
+        <field name="group_ids" eval="[(4, ref('base.group_system'))]"/>
     </record>
 </odoo>