Add an other method to disable validation on Form

[gilles-g]

Q	A
Doc fix?	no
New docs?	no
Applies to	all
Fixed tickets	-

Hi,
I think this method can be usefull for disable the group_validation.
The important question, is why set a unknow group on the group validation disable all validation, but set to false does not work?
What did you think?

[OskarStark]

An other -> Another

[xabbuh]

I am not happy with this suggestion. It's more a hack and will fail as soon as the group used here is introduced without thinking about using it here in a special way.

[gilles-g]

Hi,
I known that it's look like a hack, but I'm not satisfied by the solution proposed by the documentation also. To disable all of this, use a listener, Caution! By doing this, you may accidentally disable something more than just form validation, since the POST_SUBMIT event may have other listeners.

What the difference between my propose and this?

Maybe we need to found a real method to disable validation, not here but an issue on the github symfony..

[weaverryan]

I kind of like this, but I wonder the same thing as @Spike31 - why does setting groups to an non-existent group truly disable validation, but setting it to false doesn't. That's weird (but also out-of-scope for the docs, clearly). @Spike31 you're sure that works?

If It does work, I'd vote to only show that example. The event listener is also a hack.

But also, why are we disabling validation again? Does it hurt something to have it run?

[gilles-g]

@weaverryan If you pass a non-existent group, the validator will search for asserts with that specific group, and if nothing exist so there is no validation.

We disable the validation because it's a submit in an ajax call. We just want to submit the form with a different value for the select and change the FormEvents::PRE_SET_DATA only, we don't care about the rest of the other fields in the call.

[HeahDude]

Hi @Spike31 and thank you for this first contribution :).

To me this PR is wrong. The paragraph just above the added note says:

The reason for needing to do this is that even if you set ``group_validation``
 to ``false`` there  are still some integrity checks executed. For example
 an uploaded file will still be checked to see if it is too large and the form
 will still check to see if non-existing fields were submitted. To disable
 all of this, use a listener::

So first, I'd say this is not true about uploaded size, and the note does not change anything about that.

The max uploaded file triggers an error at the root level because it is handled by the request handler, and null is submitted, so no data is validated in such cases (see https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Form/NativeRequestHandler.php#L88). Not that children are not even submitted (because of the second argument of submit()), so no errors would be mapped on them anyway.

Second, the extra fields do trigger an error independently from the validation groups (see https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Form/Extension/Validator/Constraints/FormValidator.php#L111), so again this note does not change anything about that.

Lastly and out of scope here, "disabling" validation should be done by setting the validation_groups option to false or an empty array (which is false actually does internally). Setting it to a "random" string for this is a no-go in the docs for me.

To conclude, I propose to remove this paragraph since preventing the validation listener has no benefit:

• handling max uploaded error is done by a request handler which can be replaced or decorated in user land,
• validation groups and extra fields handling have theirs dedicated option for custom handling.

[javiereguiluz]

Closing in favor of #8940.