[5.3] Before/After validation hooks for FormRequests

[jtgrimes]

I often find that I want to munge data before I run validation and generally override the validate() function in ValidatesWhenResolvedTrait. I thought that might be useful to others, so figured I'd PR it.

(I admit, I've never had a use for afterValidation(), but I'm unable to add a before() function without an after().)

If the PR is accepted, I'll make a PR for the docs.

[taylorotwell]

Is there a strong reason you don't want to just keep overriding validate?

[jtgrimes]

I'm perfectly happy to keep overriding validate - this was just one of those rare occasions when something I do might be useful to someone else.

What would you think of a line in the docs explaining that if you want to fiddle with the data before validation, this is how you do it?

[bryannielsen]

I usually end up doing something similar to get an afterValidation hook on my FormRequests. I agree with @jtgrimes, it's not a problem to do keep doing this on an as needed basis but it could be a useful hook for other developers too.

[tomschlick]

This is something that Laravel has been sorely missing.

I remember back in the CodeIgniter days you could add mutators to the validation for things like trim or to uppercase/lowercase a field before it hit validation / the database.

[taylorotwell]

I renamed this to prepareForValidation. Got rid of after hook since we have no use case.

[juukie]

Thanks, I like this method.