So, and first of all, I must say, or repeat what many others have said:
"You can, perhaps, do almost everything in Yii, if you are able to extended and tweak it to your needs."
Again, I'm not Yii proficient, neither OOP guru, but I do believe, this last statement is true.
Despite this, however, I do understand that they should exist certain things that, for their common nature, shouldn't not require such a need for tweaks.
Here's our small history/experience:
The point, at this very beginning, was to create a form (yes, one single, form), that should allow a team to register her self. Each team can have several members, so when you insert the team, members should also be inserted, either 1, or N members. So, 1-N relationship.
Yes, we know about all the forums posts regarding "tabular" validation, and stackoverflow a lot about this, and wikis, and Yii articles regarding similar situations.
And even if you may think, "yeah that can be done!", PLEASE, without wanting to be arrogant: try it yourself first, and then tell us if you have actually been able to do it.
On a ideal design prespective immo, here's the points:
1 - CActiveForm usage on both, main _form and partials inside;
2 - Each member should be a partial;
3 - Each member should be loaded via ajax;
4 - Each member should be validated using their model rules() method;
- so that we can benefit from (consistency server-and-client side, scenario usage, easier Yii::t() integration...)
5 - Working with either Ajax Validation or Client Side validation set to true;
While this may sound simple, truth is, achieving something like this is not possible at the moment.
Re-struture the "validation" classes in order to work on "nested" models scenarios, should be something that, as far as I can tell, would be a very important step to take on Yii 2.0;
Again. I'm not saying it's not possible. But it's clearly as well, not "out of the box" either.