The purpose of onchange2() is to adress two shortcomings of onchange(): - reduce the payload of the RPC call by minimizing the diff - use the "unity" format for returning the data Because of the dependency of onchange2() on web_read(), the new method has been introduced in module web. closes odoo/odoo#119510 Signed-off-by: Raphael Collet <rco@odoo.com> Co-authored-by: Julien Castiaux <juc@odoo.com> Co-authored-by: VincentSchippefilt <VincentSchippefilt@users.noreply.github.com>