Validate also arrays

[fragsalat]

Currently the validation isn't able to validate arrays which comes from custom elements because i wasa using only the property observer. I changed that to use either the property or the array observer and to compare the old and new value deep.

This pr requires changes on binding repo. The getValue function was missing on array and collection observer.
aurelia/binding#179

[EisenbergEffect]

I have a feeling that this will not result in the correct behavior 100% of the time because there is a difference in observing a property for changes vs. observing the value of a property for it's changes (in this case an array).

@jdanyow Do you have this issue in the breeze validation work you did? I have a feeling that a number of the validation problems like this stem from the fact that the validation library does not interact with the templating library correctly. When the work was first begun on this, there was no way to get access to the View instance like there is now. Do you have any sense about this?

[jdanyow]

I think this issue needs to be migrated to aurelia-validation and aurelia/binding#179 needs to be closed. Couple of reasons for this:

1. In light of the recent decision to refactor aurelia-validation to more tightly integrate with Aurelia's templating and binding engines, it might not be a good idea to change binding's API for something in the validation internals that might change.
2. We're trying to wrap up the remaining binding items targeted for the beta and there are a number of items that take priority over this one.

Thoughts?

[EisenbergEffect]

I agree.

[plwalters]

Thanks for submitting this / commenting on this. At this time we are closing this because we have completely re-written and are deprecating the previous feature set. If you feel this should be re-opened please feel free to review this blog post and submit either again on this repository, or on the new validatejs bridge repository

Thanks again!

Tracking at aurelia/validatejs#1