lims_industry: avoid deleting components associated with samples

lims_industry/industry.py

@@ -6,6 +6,8 @@ from trytond.model import ModelSQL, ModelView, fields, Unique
 from trytond.pool import Pool
 from trytond.pyson import Eval, If
 from trytond.transaction import Transaction
+from trytond.exceptions import UserError
+from trytond.i18n import gettext
 
 
 class Plant(ModelSQL, ModelView):
@@ -400,6 +402,22 @@ class Component(ModelSQL, ModelView):
             res.append(component)
         return res
 
+    @classmethod
+    def delete(cls, components):
+        cls.check_delete(components)
+        super().delete(components)
+
+    @classmethod
+    def check_delete(cls, components):
+        Sample = Pool().get('lims.sample')
+        for component in components:
+            samples = Sample.search_count([
+                ('component', '=', component.id),
+                ])
+            if samples != 0:
+                raise UserError(gettext('lims_industry.msg_delete_component',
+                    component=component.get_rec_name(None)))
+
     def get_rec_name(self, name):
         res = self.type.rec_name
         if self.brand:

lims_industry/locale/es.po

@@ -837,6 +837,14 @@ msgstr ""
 "Ya existe para el equipo un componente del mismo tipo con la misma "
 "descripción"
 
+msgctxt "model:ir.message,text:msg_delete_component"
+msgid ""
+"You can not delete component \"%(component)s\" because it is associated with"
+" a sample"
+msgstr ""
+"No puede eliminar el componente «%(component)s» porque está asociado a una "
+"muestra"
+
 msgctxt "model:ir.message,text:msg_edit_entry_party"
 msgid "You must select all samples from the same entry to change the Party"
 msgstr ""

lims_industry/message.xml

@@ -25,6 +25,9 @@
         <record model="ir.message" id="msg_equipment_name_unique">
             <field name="text">There is already an equipment with the same name for the plant</field>
         </record>
+        <record model="ir.message" id="msg_delete_component">
+            <field name="text">You can not delete component "%(component)s" because it is associated with a sample</field>
+        </record>
         <record model="ir.message" id="msg_party_no_email">
             <field name="text">Party "%(party)s" has no Email</field>
         </record>