Question: Is it possible to coherce an array with hashes into virtus objects?

[sporto]

I have something like this:

class Book
    include Virtus.model

    attribute :name, String

    def self.all
        [
            self.new(name: 'a'),
            self.new(name: 'b'),
            ...
        ]
    end

end

So I can do: books = Book.all

But instead of doing all these self.new I will like to simply do:

def self.all
    self.some_method_that_generates_a_collection(   [
        {name: 'a}.
        {name: 'b'},
        ...
    ])
end

So just passing an array of hashes and get a collection of virtus objects back, is this possible?

I saw the example in the readme about Book and Library, but that uses two classes, with seems unnecessary and doesn't fit with the ActiveRecord way of doing things.

[dkubb]

@sporto what about something like:

def self.all
  [
    { name: 'a' },
    { name: 'b' },
  ].map(&method(:new))
end

This doesn't use any special virtus features, but rather just relies on built-in ruby features.

[sporto]

@dkubb yes, that works nicely, thanks

Maybe virtus could have a convenience method for doing this.

[solnic]

The example in the readme shows how to achieve collection member coercion when you're mutating the collection via its own interface - then you need a custom collection class.

Virtus supports coercing hashes into objects if member type is set to a virtus model or an open-struct but I'm not sure if that helps in your scenario.

[sporto]

@solnic the main issue is that when I am working on a rails codebase I want to imitate what Active records does, which is using the same class for the instance and the collection. So having a collection class doesn't fit well. Maybe it would be nice if Virtus adds a convenience way of achieving this.

[solnic]

OK but not in virtus itself. It can be a virtus plugin.

On Tue, Feb 11, 2014 at 10:26 PM, Sebastian Porto notifications@github.com wrote:

@solnic the main issue is that when I am working on a rails codebase I want to imitate what Active records does, which is using the same class for the instance and the collection. So having a collection class doesn't fit well. Maybe it would be nice if Virtus adds a convenience way of achieving this.

Reply to this email directly or view it on GitHub: https://github.com/solnic/virtus/issues/241#issuecomment-34808895