Attribute defaults

[fgarcia]

Is there any easy way to write Virtus objects where all attributes are by default "String" AND "Private" (but still shown when converted to a hash)?

Regarding private values this was my first thought:

class Foo
  include Virtus.model
  attribute :id, String
  attribute :value, String, :accessor => private
end

However while I wanted this:

a = Foo.new(id:"5", value:"5343")
a.value # access error

I got a class where the new constructor takes 0 arguments

This is more of a support question, if StackOverflow (or somewhere else) is a better place, just point me to the right direction. However I thought it was valuable asking here just to show one way I am trying to use the gem.

[solnic]

I'm not seeing this. Can you write an executable script showing the problem? And expected behavior?

[fgarcia]

Grrr... after making this gist:

https://gist.github.com/fgarcia/9277156

I realized I should solve my problem with the decorator pattern!

I still do not know how to define private attributes, but now I am starting to believe that private attributes defeat the purpose of Virtus models.

You should close this issue, I think I can solve myself how to make a Value Object out of a normal Virtus definition. It is just some rare thing where I never use normal Virtus objects. It is either as a Value Object (stateless) or as a decorated object (with state, but hiding all attributes).

[solnic]

why are you writing :accessor => private instead of :accessor => :private? :)

[fgarcia]

maaan, I dunno know if I need sleep or a big slap on my face!

Am Freitag, 28. Februar 2014 schrieb Piotr Solnica :

why are you writing :accessor => private instead of :accessor => :private? :)

Reply to this email directly or view it on GitHubhttps://github.com/solnic/virtus/issues/252#issuecomment-36401717 .

[solnic]

Shit happens, no worries :)

I suspect it works, right?

On Fri, Feb 28, 2014 at 11:39 PM, Francisco Garcia notifications@github.com wrote:

maaan, I dunno know if I need sleep or a big slap on my face! Am Freitag, 28. Februar 2014 schrieb Piotr Solnica :

why are you writing :accessor => private instead of :accessor => :private? :)

Reply to this email directly or view it on GitHubhttps://github.com/solnic/virtus/issues/252#issuecomment-36401717 .

---

Reply to this email directly or view it on GitHub: https://github.com/solnic/virtus/issues/252#issuecomment-36402008

[fgarcia]

After some sleep made it work, but here is what I expected vs what I got:

require 'virtus'

class Foo
  include Virtus.model
  attribute :name, String
  attribute :value, String, :accessor => :private
end

2.1.0 (main):0 > a = Foo.new(name:'fran', value:'a thing')
=> #<Foo:0x007fd2da8f9be8 @name="fran", @value=nil>

2.1.0 (main):0 > a.send(:value)
=> nil

2.1.0 (main):0 > a.to_hash
=> {
  :name => "fran"
}

I expected being able to define the attribute value during the object initialization.

A more controversial thing is showing private attributes when casting to_hash . Maybe everyone will have a different opinion on what should be the default behavior, but I wonder if this can be changed.

[solnic]

You want public writer and private reader, I suppose. If you set accessor to private then both writer and reader methods will be private and virtus disallows mass-assignment of attributes with private writers.

This is how it works in 1.0 at least. I will revisit this in 2.0. I'm gonna close this issue for now.

[fgarcia]

woah! impresive response time. Hope you also sleep! If we meet at any RubyConf I will owe you so many gratitude beers

I did a wrong use of :accessor, I should have written:

attribute :value, String, :writter => :private

More exactly I wanted private writter and public reader. Even so, my expectation was that private writter meant I could write during initialization, but not write afterwards. Just verified that my initialization for that :value gets ignored.

I am set to explore ROM now. I believe I was adding too many responsibilities to Virtus that fit better ROM.

Thank you so much also for all the work on that front!

[solnic]

In that case you want to use Virtus.value_object which doesn't allow changing an object after it was initialized.

Re beers and confs, I'm going to wroc_love.rb and RedDotRubyConf this year ;) Maybe some more ;)

[bguest]

It would be nice to be able to mark some attributes as imutable, ie you can define them durring initialization, but not after ie:

class User
  attribute :user_id, Integer, :accessor => :immutable
  attribute :name, String
end

uu = User.new(:user_id => 33)
uu.user_id  #=> 33
uu.user_id = 10      #error
uu.name = 'Bob'
uu.name  #=> 'Bob'