[Form] Filter arrays out of scalar form types

[nicolas-grekas]

Q	A
Branch?	3.4
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	#4102
License	MIT
Doc PR	-

Replaces fix #20935

[HeahDude]

Thanks! Finally closing this old issue 🎉

[nicolas-grekas]

Now with tests, ready.

[dmaicher]

Interesting test 😄

[nicolas-grekas]

Why do we need to check for the multiple option here? Such a hard coded knowledge about type specific options looks suspicious to me.

"multiple" is exactly the info we're missing to decide if we allow arrays or not: form types that know how to deal with array of values don't have to be compound, and "multiple" is their way to express they still deal with arrays. Note that this is already what we use, that's why the patch is so simple yet it works and tests are green.

[ro0NL]

Can we check if the type is actual multiple, i.e. getOption('multiple', false) instead of hasOption('multiple').

Is the same check needed vice versa? If the submitted data is scalar and the type is compound/multiple?

[nicolas-grekas]

@ro0NL that's how I first wrote the patch, but the tests broke all around. The reason is that we don't need to decide if arrays are allowed. Instead we need to decide if arrays are dealt with at the form type level. All form types that declare multiple true/false can do that.

[nicolas-grekas]

rebased - ready

[bvisonl]

I was using the type of TextType::class to submit an array to a data transformer, I am unclear to what could be the alternative to TextType in this scenario in case I need this data to be an array, can anyone provide some guidance?

[TrickyC94]

I was using the type of TextType::class to submit an array to a data transformer, I am unclear to what could be the alternative to TextType in this scenario in case I need this data to be an array, can anyone provide some guidance?

I'm on the same situation. Things worked before this update

[omarboussarsar]

This code can help you to bind an array with a TextType by serializing the array before the submit.
(In my case I need to serialize all the children of my form type).

$builder->addEventListener(FormEvents::PRE_SUBMIT, function (FormEvent $event) {
    $event->setData(array_map(function ($value) {
        return serialize($value);
    }, $event->getData()));
})