@timriley Is there any plan to have anything in dry-types that mimics what Virtus does now (a “typed” PORO)?
@timriley Correct me if I’m wrong, but
Struct doesn’t do that (as it doesn’t provide writers, only readers)
dry-types isn’t going to encourage mutable state for your objects :)
Struct already gives you “typed” objects, just doesn’t give you a way to mutate them after creation
@timriley Hmm, that definitely put things at odds with using trailblazer in Rails (after validation it writes properties one at a time). I may have to rething how I go about this ;)
I guess there’s nothing to stop me from creating an evil mutable Struct :P
Yeah, ideally you can create your objects in one hit, with a full set of valid attributes.
Unfortunately that becomes really tough when you’re trying to piecemeal clean up an existing Rails app
Added 3 more sections!
And 1 extra pun.
@timriley An evil (and lazy) hack for a mutable struct:
module Dry
module Types
class Struct
class Mutable < Struct
constructor_type :schema
def self.attributes(new_schema)
super
protected_writer(*new_schema.keys)
self
end
def self.protected_writer(*writers)
writers.each do |key|
define_method("#{key}=") do |value|
instance_variable_set("@#{key}", self.class.new(key => value)[key])
end
end
end
end
end
end
end
And now I will go hang my head in shame ;)
heh
Piotr predict someone one day will change read only, not mutable dry-tapes into this ;]
but it's ok as a plugin, there should be something like this for easy moving from Virtus for example
@timriley again another awesome article :clap: :+1:
Thanks @tak1n!
@gotar Yes, that's exactly our use case. I also have a fairly unique import scenario where struct are composed of values from several different files. Difficult to do if everything's read only
Or write-once, I guess :)
BTW anyone know why you have to specify the leading
@ in instance_variable_set/get? I'm not aware of instance variables that don't begin with @, always got on my nerves
@pnomolos keep in mind that all type checks are performed in
.new method
@AMHOL you can patch
Kernel and fix it ;) Kind of
:see_no_evil: :hear_no_evil: :laughing:
Folks, done with integration tests: dry-rb/dry-validation#147
@pnomolos you'd be better off with something like:
module Dry
module Types
class Struct
class Mutable < Struct
constructor_type :schema
def self.attributes(new_schema)
super
define_protected_writers(*new_schema.keys)
self
end
def self.define_protected_writers(*writers)
writers.each do |key|
define_method("#{key}=") do |value|
instance_variable_set(
"@#{key}",
self.class.schema[key][value]
)
end
end
protected *writers
end
end
end
end
end
Nice one @jodosha, I'll check it out after work :+1:
@flash-gordon yeah my quick hack was to have the writer construct a new
Fair do
@pnomolos oh, I missed it, sorry :)
@AMHOL yeah was working towards that - my first attempt was a really lazy version :D
@jodosha I'm in the process of adding specs for the includes and excludes predicates in Dry-Validation and have found another collection of failures. Shall I just mark them with an X as you did?
@AMHOL dry-container now has 100% coverage. Officially :)
I mean I fixed codeclimate stats
@flash-gordon brilliant, thank you :D