I'm 👍 for this addition, but I made several comments about the implementation.

@fabpot Comments addressed

The failing tests seems to not be related.

Fatal error: Call to undefined method Symfony\Component\DependencyInjection\Definition::getParent() in /home/travis/build/symfony/symfony/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php on line 535

Can we add a check to the constraint that ensures that the format string is something that is understood by DateTime::createFormFormat()?

@dosten Can you make the missing changes?

@xabbuh I'll work on this ASAP

@xabbuh The DateTime::createFromFormat() method can return false when the given string does not match the format, but this is already covered by this statement: https://github.com/dosten/symfony/blob/validator/add-datetime-format/src/Symfony/Component/Validator/Constraints/DateTimeValidator.php#L51-L58
Also, the format can be anything, for example this code is valid: DateTime::createFromFormat('foo', 'foo'), so, any string is understood by DateTime::createFromFormat()

Thanks for that feature 👍

Some feedback? @xabbuh @webmozart @fabpot

@dosten But wouldn't be better to use a different error code if the format string cannot be parsed?

@xabbuh can you give an example of a "unparsable" format?

@dosten Take this example:

$date = \DateTime::createFromFormat('f.m.Y', '27.02.2016');

\DateTime::getLastErrors() will now contain something like this:

Array (
    [warning_count] => 0
    [warnings] => Array
        (
        )

    [error_count] => 3
    [errors] => Array
        (
            [0] => The format separator does not match
            [1] => The separation symbol could not be found
            [5] => Trailing data
        )

)

see https://3v4l.org/tTAvU

@dosten Any news on this one?

@fabpot @xabbuh The "f" format char does not exists, so your code is expecting a format like: "f.02.2016":

$date = \DateTime::createFromFormat('f.m.Y', 'f.02.2016');

\DateTime::getLastErrors() will now contain something like this:

Array
(
    [warning_count] => 0
    [warnings] => Array
        (
        )

    [error_count] => 0
    [errors] => Array
        (
        )

)

If you pass "27.02.2016" the validator will add a INVALID_FORMAT_ERROR violation, IMO this is correct.
I can add a test case for this to prove that this works correctly.

Ah yes, you are right. I missed that you have to use these characters if they are present in the user input. Sorry for the confusion.

👍

Status: Reviewed

Thank you @dosten.

@dosten Can you submit a PR on symfony/symfony-docs to document this new feature? Thanks.

@dosten You can refer to symfony/symfony-docs#6313 (I created it so that we do not forget about this feature).

Nice feature, thanks!