So this bug is kinda funky. The code path is basically "if we weren't passed an
instance of the class we compose to, and we have a converter, call that".
Ignoring the hash case for a moment, everything after that was roughly intended
to be the "else" clause, meaning that we are expected to have an instance of
the class we compose to. Really, we should be blowing up in that case, as we
can give a much better error message than what they user will likely get (e.g.
`NameError: No method first for String` or something). Still, Ruby is duck
typed, so if the object you're assigning responds to the same methods as the
type you compose to, knock yourself out.
The hash case was added in 36e9be8 to remove a bunch of special cased code from
multiparameter assignment. I wrongly assumed that the only time we'd get a hash
there is in that case. Multiparameter assignment will construct a very specific
hash though, where the keys are integers, and we will have a set of keys
covering `1..part.size` exactly. I'm pretty sure this could actually be passed
around as an array, but that's a different story. Really I should convert this
to something like `class MultiParameterAssignment < Hash; end`, which I might
do soon. However for a change that I'm willing to backport to 4-2-stable, this
is what I want to go with for the time being.
Fixes#25978
This behavior was broken by 36e9be85. When the value is assigned
directly, either through mass assignment or directly assigning a hash,
the hash gets passed through to this writer method directly. While this
is intended to handle certain cases, when an explicit converter has been
provided, we should continue to use that instead. The positioning of the
added guard caused the new behavior to override that case.
Fixes#25210
This reverts commit 14fc8b3452.
Reason: we need to discuss a better path from this removal.
Conflicts:
activerecord/lib/active_record/reflection.rb
activerecord/test/cases/base_test.rb
activerecord/test/models/developer.rb
This feature adds a lot of complication to ActiveRecord for dubious
value. Let's talk about what it does currently:
class Customer < ActiveRecord::Base
composed_of :balance, :class_name => "Money", :mapping => %w(balance amount)
end
Instead, you can do something like this:
def balance
@balance ||= Money.new(value, currency)
end
def balance=(balance)
self[:value] = balance.value
self[:currency] = balance.currency
@balance = balance
end
Since that's fairly easy code to write, and doesn't need anything
extra from the framework, if you use composed_of today, you'll
have to add accessors/mutators like that.
Closes#1436Closes#2084Closes#3807
This makes it possible to filter invalid input values before they are passed
into the value-object (like empty strings). This behaviour is only relevant
if the :allow_nil options is set to true. Otherwise you will get
the resulting NoMethodError.
