[FIX] web: form: combine field and renderer classnames

The rendering of field widgets is asynchronous (as it returns a
native Promise). However, the '_renderFieldWidget' method of basic
renderers is sync, and returns a fake div that will be replaced by
the widget'$el afterwards.

The form renderer sometimes needs to add classNames on the rendered
nodes (e.g. each child of an outer group as class 'o_group_col_x').

To handle this, once the field widget is ready, we copied all
attributes of the fake node to the widget's node. Unfortunately, we
were erasing the attr value (e.g. className) by the new one. As a
consequence, the className defined in the widget were lost. This
could be observed for the 'note' field in 'sale.order'.

As this was only necessary for classNames, this rev. only retrieves
the class attribute of the fake node, and adds it to the classNames
of the widget's $el.

closes odoo/odoo#34528

Signed-off-by: VincentSchippefilt <VincentSchippefilt@users.noreply.github.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/addons/web/static/src/js/views/basic/basic_renderer.js b/addons/web/static/src/js/views/basic/basic_renderer.js
index 4c03d9b77a1..d01bf40669e 100644
--- a/addons/web/static/src/js/views/basic/basic_renderer.js
+++ b/addons/web/static/src/js/views/basic/basic_renderer.js
@@ -590,8 +590,8 @@ var BasicRenderer = AbstractRenderer.extend({
             // this.renderFieldWidget(...).addClass(...), the class is added on
             // the temporary div and not on the actual element that will be
             // rendered. As we do not return a promise and some callers cannot
-            // wait for this.defs, we copy those attributes to the final element.
-            widget.$el.attr($el.getAttributes());
+            // wait for this.defs, we copy those classnames to the final element.
+            widget.$el.addClass($el.attr('class'));
 
             $el.replaceWith(widget.$el);
             self._registerModifiers(node, record, widget, {