Ruby on rails named scope implementation?

There are two tricks (or patterns if you will) employed in the named_scope magic Proxy pattern calling a named scope method on a class or an association always returns an instance of the ActiveRecord::NamedScope::Scope class, not a colleciton of filtered AR objects. This pattern, altough very useful, makes things kind of blurry sometimes, since the proxy objects are ambivalent in their nature Lazy loading thanks to lazy loading (which in this context means - hitting the database only if neccessary) named scopes can be chained up to the point when you need to work with the collection defined by the scopes. Whenever you request the underlying colleciton, all the chained scopes are evaluated and a database query is executed One final note: There's one thing to have in mind when playing with named scopes (or with any thing that uses delegation of some kind) in IRB.

Everytime you hit Enter, the thing you wrote beforehand is evaluated and the inspect method is called on the returned value. In the case of chained named scopes, although the whole expression is evaluated to a Scope instance, when the IRB calls the inspect method on it, the scopes are evaluated and the database query is fired. This is caused by the fact that the inspect method is by means of delegation propagated through all the scope objects up to the underlying collection.

You might want to try this class Order 'updated {:pay_type => :check}) end end end usage is the same @orders = Order. Last_n_days(5) @orders = Order. Checks @orders = Order.checks.

Last_n_days(5) This still does all the lazy loading you love. That is, it won't make a query until you attempt to access the records. Bonus: Rails 3 compatible!

Named Scopes Are Dead.

Very cool. I was thinking of doing something like this in Javascript but Javascript behaves rather weird. The statement: var x = SomeObject; does not call SomeObject's toString() function.

But the statement: var x; x = SomeObject; correctly calls the toString() function as expected. This prevents Javascript from doing cool stuff with chaining. =(.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.