Active Model - work in progress, questions and thoughts

rubyonrails-core
1

Hello, World!

I've been doing some hacking on ActiveModel, and I'm pretty satisfied with the results. Mmost of the validations stuff is finished. Callbacks and observing is yet to come (though Rick Olson has done some work on the observers).

Here's one of the tests, which mocks an active record implementation of AtiveModel: http://pastie.org/185638

It lets you overwrite default validation settings. It detects if the implementation defines new_record?, if it does, ActiveModel activates new/existing record differences. If it doesn't, stuff like :on => :update is ignored.

The API is pretty clean, and yes, the tests pass ; ) I'm poking around with error messages now, trying out various approaches. I think the basic idea of Errors < Hash is DHH's, and I really based my stuff on his approach, just tweaking it a bit. For instance, instead of user.errors[:base] << "foo", I've done user.errors << "Foo" (which was to be honest Pratik's idea). Also, instead of user.errors[:base] for yielding them, I'm doing user.errors.on_base. It's a very different kind of error than the attribute-based errors you add with foo.erros[:bar], so I think it makes sense to have the api different for those as well.

Certain things makes backwards compability hard, though. I've changed it so that adding errors on base causes the record to be invalid, which as far as I know breaks backwards compability (this is the first time I hack around whith in-deep rails stuff like this, so do arrest me on this if I'm wrong). Therefore, aiming for ActiveModel being a none backwards compatible 3.0 thing would make sense. As mentioned, it would really easen the process of coding it, and makes it less hacky. And it really affects active record as well, involving a lot of re- writing, so the 3.0 badge would indeed be deserved for a release like this.

So, that's it. My work so far is available on github, http://github.com/leethal/rails/tree/activemodel_cleanup/activemodel. I hope you like what I've done so far, I've really enjoyed hacking on this. Comments appreciated =)

2

I think you're getting a little ahead of yourself. We still haven't made any real decisions about the direction of ActiveModel. Its pretty experimental at this point.

Please feel free to continue to play around but don't assume we are going be taking your direction.

Also, I think we are going go w/ rspec too.

3

I didn't really see where he was getting ahead of himself. He's done a lot of hacking on this and he was saying that if you take his patches/changes then backwards compatibility could be hard. If you don't, well, who cares? That's the beauty of Git: he can maintain his own repos of the code, you can maintain yours.

Also, I think perhaps you're getting ahead of yourself, since I don't see your name on Redirecting… (at least not yet :)). I'd like to get Rick Olson's take on it (and I think Rick Bradley has been involved), since I know he has taken a look at this stuff previous to this ML message.

As for myself, I think this stuff is really cool. I had someone ask me about something like this (or, well, a little more than this...closer to DataMapper I guess) at MySQLConf, so it's cool to see something materializing. I'm going to start toying around with this and ActiveRelation once it's substantial enough to tinker with. I'm really excited to see where the model layer in Rails is going...

--Jeremy

4

I didn't really see where he was getting ahead of himself. He's done a lot of hacking on this and he was saying that if you take his patches/changes then backwards compatibility could be hard. If you don't, well, who cares? That's the beauty of Git: he can maintain his own repos of the code, you can maintain yours.

This is, indeed, the beauty of distributed source control, and experimentation with ActiveModel should be encouraged. However it's missed the 2.1 boat, so lets not get too worried about what is and isn't yet fit for the core of the framework. We have until (2.1).next to worry about such things.

Also, I think perhaps you're getting ahead of yourself, since I don't see your name on Redirecting… (at least not yet :)). I'd like to get Rick Olson's take on it (and I think Rick Bradley has been involved), since I know he has taken a look at this stuff previous to this ML message.

I know rick's been tinkering with ActiveModel in the past, but I'm not sure how 'in anger' the use has been. Though you're probably in a better position to know whether or not the entp projects are doing anything like this.

As for myself, I think this stuff is really cool. I had someone ask me about something like this (or, well, a little more than this...closer to DataMapper I guess) at MySQLConf, so it's cool to see something materializing. I'm going to start toying around with this and ActiveRelation once it's substantial enough to tinker with. I'm really excited to see where the model layer in Rails is going...

I'm also looking forward to giving active record a bit of a kicking, bi-directional associations and an identity map for starters, but I see ActiveModel as something else entirely. I'm having trouble seeing it materialise into something useful until we have an alternative method of persistence to target. ActiveResource got by fine without it, perhaps we need active document, active flat-file, active in-memory-thing or something similar to get a feel for what's needed.

5

Hey peeps,

Glad you find my stuff at least semi-sensible =)

The reason I'm hacking on it, is beacuse after asking about it's status in #rails-contrib Rick Olson suggested that I'd start hacking away on it. It was he hat suggested posting this mailing list as well.

The way I see it, ActiveModel is about tearing apart various libs inside ActiveRecord and making them stand-alone, so that 1. the active record code itself gets a lot cleaner, and that 2. people can include ActiveModel libs in their own code, without having to use active record. E.g. databaseless models in a rails app that has validations and callbacks in them.

Rick Olson has been saying all along that this wouldn't get into 2.1, so that has never been my goal anyway. DHH also said he was okay with making Active Model a 3.0 thing (in #rails-contrib), so I guess that makes sense then.

But really, I've just been playing with this, and I'm not a super experienced Ruby coder (which you can tell from the read_inheritable_attribute stuff in the validation settings part of my hacks =P), so I'm not having any high hopes of the core team embracing my ideas and hacks from day one.