Vaadin Flow 24.4.0.alpha4 validation process

[alexanoid]

Description of the bug

1. With 24.4.0.alpha4, something changed in the form validation process. Once I enter the first value, it immediately highlights the entire form with validation errors on the mandatory fields:

Previously, in version 24.4.0.alpha2, the validation started working only after I pressed the Save button. How can I control this behavior in version 24.4.0.alpha4?

Expected behavior

Validation should not highlight fields until the Save button is clicked.

Minimal reproducible example

n/a

Versions

• Vaadin / Flow version: 24.4.0.alpha4

[mcollovati]

Thanks for reporting. Could you please create a separated ticket for the drawer issue? It would be simpler to track

[alexanoid]

sure, done #18736

[mcollovati]

@alexanoid could you please share the Binder configuration code?
I tried to reproduce with binder.forField(...).asRequired("You must fill this").bind(.....) but the validation is only triggered on the edited field.

EDIT: never mind. I can reproduce the issue by calling Binder.setBean()

[alexanoid]

@mcollovati yes, I use Binder.setBean() method too

[tepi]

In at least 24.2 and 24.3, Binder.setBean() had a bug that allowed writing an invalid state to the bean since only the binding that had value change triggered would be validated, hence all the other required and empty fields which had not been touched were basically ignored, resulting into the bean being in an invalid state. This was fixed via #18535 which causes all the bindings to be validated on value change - which is causing the behavior seen here.

Quick fix for you is to use readBean and writeBean instead which should work as the buggy setBean before.

Current funtionality of setBean does not seem acceptable, but we can't roll back to previous implementation since setBean (like writeBean) should always guarantee the validity of the data written to the bean. I'll investigate if there's a way to only highlight the changed field if needed, but silenty validate all the bindings so we can keep that guarantee.