I tried to deprecate TranslatableMessage::__toString but then it creates a deprecation when writing

if label is empty

because of the twig implémentation

public static function testEmpty($value): bool
    {
        if ($value instanceof \Countable) {
            return 0 === \count($value);
        }

        if ($value instanceof \Traversable) {
            return !iterator_count($value);
        }

        if ($value instanceof \Stringable) {
            return '' === (string) $value;
        }

        return '' === $value || false === $value || null === $value || [] === $value;
    }

Not sure how to do then @stof @xabbuh ?

Also it means that removing the toString method in 8.0 will imply that such thing as

new TranslatableMessage('');
new StaticMessage('');

won't be considered as empty anymore.

I extracted the first fix in #61111

If the form theme relies on checking whether a TranslatableMessage is empty before translating it, it is broken, as it checks the emptyness of the wrong string.
A TranslatableMessage could have a non-empty key producing an empty message.

If the form theme relies on checking whether a TranslatableMessage is empty before translating it, it is broken, as it checks the emptyness of the wrong string. A TranslatableMessage could have a non-empty key producing an empty message.

If it's broken then how would you "fix" it @stof ?

I'm not sure we could call this broken since it's the same with "string key".
You could decide to have a non-empty string key producing an empty message too ; and the check will be done before translating. So the check seems consistent.

My main issue is currently the fact that

• If I have a toString in TranslatableMessage and not StaticMessage, the behavior will be different.
• If I trigger a deprecation in TranslatableMessage::__toString, it will be trigger in twig.

Should I just add @deprecated without a trigger_deprecation call ?

The fix might be to NOT wrap empty strings into TranslatableMessage. Is that possible?

The fix might be to NOT wrap empty strings into TranslatableMessage. Is that possible?

We can "forbidden" this with

• a @param non-empty-string phpdoc
• An InvalidArgument if a empty string is given on Symfony 8
• A deprecation on Symfony 7

But that does not solve the fact that a deprecation in the __toString method will be triggered by twig/twig when doing the is empty test: '' === (string) $value because of the current implementation #61109 (comment)

For this, I dunno what to do @nicolas-grekas :/

Can't we replace the empty check by a simple if msg one?

Can't we replace the empty check by a simple if msg one?

Great, it solves everything.

I just need #61111 to be merge into 7.4 now.

Thank you @VincentLanglet.