Symfony5: setting ['required'=>false] to the form prevents overriding "required" in fields

[Ser5]

Symfony version(s) affected: 5.2.1

Description
The issue stems from here:
https://stackoverflow.com/questions/65823351/symfony5-forms-how-to-disable-required-for-all-fields-by-default

Symfony has the required flag enabled by default for all form fields - the feature I don't need, I need to have it backwards - to have all fields not required by default.

I have two methods on my mind to do this:

1. Set ['required'=>false] to the very top form
2. Force ['required'=>false] via an extension

But both methods produce puzzling results:

• If I don't set any required on the form, then for the individual fields I can set required to whichever I want - true or false
• If I set ['required'=>true] on the form, I can freely override required also
• But if on the form I set ['required'=>false], then Symfony refuses to override required on any individual field - required stays false forever
• The same results I get when forcing ['required'=>false] with the help of an extension

For the demonstration see the test project I put on github. It creates a form and 3 fields inside it.

• 1st field uses default required
• 2nd one uses ['required'=>true]
• 3rd one uses ['required'=>false]

When you run the index.php from CLI, it shows required values for these 3 fields.

You can modify the behavior of the form by using command-line options:

• No options - form with default required
• --set=form --required=true - form with ['required'=>true]
• --set=form --required=false - form with ['required'=>false]
• --set=ext --required=false - form with required forced to false via an extension

How to reproduce
https://github.com/Ser5/SymfonyRequireBug

git clone https://github.com/Ser5/SymfonyRequireBug.git
cd SymfonyRequireBug/lib/
composer install
cd ../

php index.php
php index.php --set=form --required=true
php index.php --set=form --required=false
php index.php --set=ext --required=false

The main question is: is this behavior intended? I find it totally confusing and counterintuitive. Or is this a bug? Should it be fixed?

Possible Solution
Allow overriding required on form fields despite the value set on the form.

Additional context
Windows 10
PHP 8

[Ser5]

Are there any updates? Is it a bug or a feature?

I was poking the code here and there myself. What I found:

• Fields in the Form object doesn't use any options inheritance
• Options inheritance is applied inside createView() method
• There is a loop inside, which creates views for all the children by calling $child->createView($view)
• Then, for each child, it enters $type->buildView($view, $this, $options);
• Where it calls $this->parent->buildView($view, $form, $options); - where the parent is the form itself
• Inside the form it calls $this->innerType->buildView($view, $form, $options);
• Which goes into FormType::buildView()
• Containing array_replace(), which replaces view vars with some other values, where the required is replaced by the result of isRequired() method
• That isRequired() - it's called for each child (form field), and each child is an instance of Form
• Therefore, for checking a field required value, Form::isRequired() is called
• That method contains some odd code: it first checks vars of the parent element, which is in our case is a form:
  1. If the form has required=true, the field returns it's own value - which can be true or false
  2. But if the form has required=false, the field ignores everything and always returns false
  3. Also, if we didn't explicitly set form's require to anything, it defaults to true, and everything acts as variant 1

As a result, whenever a form has required=false, all the fields are forced to have required=false also.

I see this as a bug, and understand as follows: required has only two possible values - true and false, and mixes two behaviors - "whether the value is set/not set" and "whether the value has true/false":

• When required has true, Symfony silently assumes that it can be a default value and allows to override it
• When required has false for the parent element and true for the child element, Symfony assumes that false one is set manually by the user, and true one is the default - then skips that "default", inheriting "manual" false

Actually required should has three states: not set, true, false:

• If not set, then inherit from a parent type, or use default hardcoded - true for example
• true - use true, don't inherit, don't use default value
• false - use false, don't inherit, don't use default value

Is this info useful for the issue?

[xabbuh]

Even though this can be confusing I think that the current behaviour is correct. If a parent type is not required, rendering its children as required would be confusing. Or put differently: If the child is required, its parent would then have to be required too. Does that make sense?

[xabbuh]

I am going to close here as I don't think there is anything that needs to be changed (see my previous comment). Though please feel free to comment if you don't agree or if you have further questions and we can consider to reopen.

[VincentLanglet]

I just found this issue, and it's really confusing @xabbuh, I think it should be reopen.

There is often a * used in order to tell if a field is required or not.
When I use a CollectionType, I do not want this * since adding a row to the collection is not required

But if I use required => false on the CollectionType, I lose the required attribute on all the children

Become

And I'm looking for

[xabbuh]

@VincentLanglet Please open a new issue. I think your case is more special than the generic request where this issue came from.

[VincentLanglet]

Done @xabbuh #41368

[willherzog]

@Ser5 If you're still looking for a solution, I discovered that this can be accomplished with a form extension that applies to each type directly (e.g. ChoiceType, TextType, etc.) rather than extending FormType. @xabbuh The issue is that FormType is technically a parent form and thus setting required false on it (i.e. in a form extension) overrides that option on every form type. It would be nice if there were a more convenient way to change the default while still preserving the parent > child behavior you cited.

[renepupil]

If a parent type is not required, rendering its children as required would be confusing.

@xabbuh I also think the current behavior is more confusing: most default options set on form class can be overwritten or extended by field options (e.g. label, constraints etc.).

Therefore it makes it more similar to other options if the "required" attribute in a field option overwrites the default required "false"...

[Kryyto]

I'd like to add that calling required a boolean is misleading. Sure it IS a boolean, but in practice it's not used like most would think at first.

For whatever reason, boolean attributes are true when existing and false if missing.

Which means that the correct writing is not: required="true" or required="false"
But this: required or nothing if you want it false

Where I got this info:
https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/required

Some example provided: