NotBlank validator should not invalidate null values

[Taluu]

Description
In most validators, there's a failsafe mecanism that prevent the validator from validating if it's a null value, as there's a validator for that (NotNull). I think NotBlank shouldn't bother on null values, especially as NotBlank and NotNull are used together to prevent null values too.

Not really a feature request, but not really a bug too... more like a RFC but for all versions. But I guess this would be a BC break though. :/ So maybe add a deprecated on the validator if it's a null value or something, and remove the null invalidation from the NotBlank on 5.0 ?

Currently, we need to reimplement the validator just to skip null values...

Possible Solution
Either deprecate the validation on null value in NotBlank, or do as in most validators, (if null value, then skip). But as I mentionned, this would probably be a bc break.

[stof]

That would be a huge BC break.
And due to the form component setting properties to null when submitting an empty field, it might even be confusing to change the behavior of NotBlank. So I'm not sure it is worth it.

[theofidry]

Maybe we could add a NullOrNotBlank and potentially rename NotBlank to NotNullNotBlank. I'm not too happy with the names but IMO it's the original name that is messed up and we can't change it without BC breaks.

On a side note, I witnessed at least 10 Symfony projects where they declared a NotBlank ignoring null values, so I also strongly feel there is an issue here.

[ostrolucky]

especially as NotBlank and NotNull are used together to prevent null values too.

Can you provide a source for this? We always use just NotBlank. Usage for NotNull is really rare in projects I've seen.

rename NotBlank to NotNullNotBlank

How is "not blank" value ever null value? Blank includes null.

I witnessed at least 10 Symfony projects where they declared a NotBlank ignoring null values,

For what use case?

[theofidry]

@ostrolucky because there is a need to check for non null empty values. null is often given either as "reset" or "not provided" value.

You can always argue that a form (for an API or not) - and I agree on paper. But in practice for a lot of front-ends omitting non provided fields as opposed to sending null requires too much work for what it's worth, hence this need in the back-end.

[ostrolucky]

If you have a text type field in your form and don't type anything there, it's transformed to null. If you omit that field completely, it's again null. There is no difference. This kind of problem is meant to be solved with validation groups.

[theofidry]

@ostrolucky I don't really see how that invalidates the points above tbh

[xabbuh]

If I don't misunderstand the proposal that would pretty much the same as having the Length constraint with min set to 1, isn't it?

[theofidry]

Provides the value is a string but NotBlank also works on other types

…

On Sun 8 Jul 2018 at 20:46, Christian Flothmann ***@***.***> wrote: If I don't misunderstand the proposal that would pretty much the same as having the Length constraint with min set to 1, isn't it? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#27876 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AE76gXwgY2hK-pKQnpLUU9zMM-Y0c-0Pks5uElOMgaJpZM4VFUrc> .

[xabbuh]

How do you use it with other types if you do not want to fail on null? I mean do you rely on implicit type casts here?

[theofidry]

No we do explicit casts in your blank validator. We don't rely on empty() and if the value is null we don't validate it with this constraint

[xabbuh]

Well, my point is I don't see a use case for the NotBlank constraint when you are not validating a string. For other types there are better constraints IMO. Based on this assumption we only need to discuss whether or not we need to distinguish null from the empty string which brings us back to the question if we need a shortcut for the Length constraint with a minimum length of 1.

[ogizanagi]

@xabbuh : The issue with the Length constraint is that it ignores empty strings:

symfony/src/Symfony/Component/Validator/Constraints/LengthValidator.php

Lines 32 to 34 in b226859

	if (null === $value || '' === $value) {
	return;
	}

[theofidry]

Which makes no sense to me neither tbh...