Group call to on_change_with for later fields

Closes #12218

proteus/proteus/__init__.py

@@ -1176,13 +1176,15 @@ class Model(object):
             changes = getattr(self._proxy, 'on_change_with')(values,
                 list(to_change), context)
             self._set_on_change(changes)
-        for field in later:
-            on_change_with = self._fields[field]['on_change_with']
-            values = self._on_change_args(on_change_with)
+        if later:
+            values = {}
+            for field in later:
+                on_change_with = self._fields[field]['on_change_with']
+                values.update(self._on_change_args(on_change_with))
             context = self._context
-            result = getattr(self._proxy, 'on_change_with_%s' % field)(values,
-                    context)
-            self._on_change_set(field, result)
+            changes = getattr(self._proxy, 'on_change_with')(
+                values, list(later), context)
+            self._set_on_change(changes)
 
         if self._parent:
             self._parent._changed.add(self._parent_field_name)

sao/src/model.js

@@ -1144,18 +1144,32 @@
                 }
                 this.set_on_change(result);
             }
-            for (fieldname in later) {
-                on_change_with = this.model.fields[fieldname]
-                    .description.on_change_with;
-                values = this._get_on_change_args(on_change_with);
+            if (!jQuery.isEmptyObject(later)) {
+                values = {};
+                for (fieldname in later) {
+                    on_change_with = this.model.fields[fieldname]
+                        .description.on_change_with;
+                    values = jQuery.extend(
+                        values,
+                        this._get_on_change_args(on_change_with));
+                }
+                fieldnames = Object.keys(later);
                 try {
-                    result = this.model.execute(
-                        'on_change_with_' + fieldname,
-                        [values], this.get_context(), false);
+                    if (fieldnames.length == 1) {
+                        fieldname = fieldnames[0];
+                        result = {};
+                        result[fieldname] = this.model.execute(
+                            'on_change_with_' + fieldname,
+                            [values], this.get_context(), false);
+                    } else {
+                        result = this.model.execute(
+                            'on_change_with',
+                            [values, fieldnames], this.get_context(), false);
+                    }
                 } catch (e) {
                     return;
                 }
-                this.load(fieldname, false).set_on_change(this, result);
+                this.set_on_change(result);
             }
         },
         set_on_change: function(values) {

tryton/tryton/gui/window/view_form/model/record.py

@@ -632,18 +632,27 @@ class Record:
             except RPCException:
                 return
             self.set_on_change(result)
-        for fieldname in later:
-            on_change_with = self.group.fields[fieldname].attrs.get(
-                    'on_change_with')
-            values = self._get_on_change_args(on_change_with)
+        if later:
+            values = {}
+            for fieldname in later:
+                on_change_with = self.group.fields[fieldname].attrs.get(
+                        'on_change_with')
+                values.update(self._get_on_change_args(on_change_with))
             try:
-                result = RPCExecute('model', self.model_name,
-                    'on_change_with_' + fieldname, values,
-                    context=self.get_context())
+                if len(later) == 1:
+                    fieldname, = fieldnames
+                    result = {}
+                    result[fieldname] = RPCExecute(
+                        'model', self.model_name,
+                        'on_change_with_' + fieldname,
+                        values, context=self.get_context())
+                else:
+                    result = RPCExecute(
+                        'model', self.model_name, 'on_change_with',
+                        values, list(later), context=self.get_context())
             except RPCException:
                 return
-            # Load fieldname before setting value
-            self[fieldname].set_on_change(self, result)
+            self.set_on_change(result)
 
     def autocomplete_with(self, field_name):
         for fieldname, fieldinfo in self.group.fields.items():

trytond/trytond/model/modelview.py

@@ -773,6 +773,7 @@ class ModelView(Model):
             field = self._fields[fieldname]
             method_name = 'on_change_with_%s' % fieldname
             value = getattr(self, method_name)()
+            setattr(self, fieldname, value)
             if field._type in {'many2one', 'one2one', 'reference'}:
                 if isinstance(value, ModelStorage):
                     if value.id and value.id >= 0: