Note: YML and XML examples for configuration are not included. Worked with weaverryan to try to come up with a working version in YML without success.

This gist contains the YML configuration I tried:
https://gist.github.com/afishnamedsquish/5277987

The issue was that the constraint for the field needed to be parsed into an instance of Required or Optional and instead it was always parsed into an array with a single instance of Required or Optional in it. Might be a YML limitation or just something wrong with the syntax I tried.

Fixed whitespace issues from your comments.

you should add the YAML and XML mapping too

@stof it seems like this is not possible with Yaml and Xml. Afishnamedsquish, Ryan and I have tried it but can't come with a solution. Even bernhard didn't know the format, see also:https://gist.github.com/afishnamedsquish/5277987
If you know it, you're welcome to post it! ;-)

@wouterj This should be reported as a bug if YAML and XML don't support it. Can you open a ticket ?

@stof, yes I will do

Hey!

This is a really nice entry - very clearly explained, nice work! I did tweak some minor language at sha:cf049ed, because iirc,Required doesn't really make the key required, it just means that the validation rules will be applied always (and so theNotBlank really makes it required).

Thanks!

This works for me:

Acme\AuthorBundle\Entity\Author:properties:profileData:             -Collection:fields:alternate_email:constraints:                            -Collection\Optional:                                -Email:~

Can someone confirm?

negative for sf2.1 (didn't test it in other versions)

Now thatsymfony/symfony#7930 is merged. Is any work left here?

An example of YML configuration could be added to the docs

And a xml example

You're right, see#2841 for this.