I'm .clone -ing a record in rails...
new_blerg = Blerg.find(1).clone
This record has loads and loads of associations, and those associations even have associations.
Is there a way to deep-copy a record and clone it so it is cloned with all of those associations too?
You may get some good use out of the Amoeba gem for ActiveRecord 3.2.
It supports easy and automatic recursive duplication of has_one, has_many and has_and_belongs_to_many associations, field preprocessing and a highly flexible and powerful configuration DSL that can be applied both to the model and on the fly.
be sure to check out the Amoeba Documentation but usage is pretty easy...
just
gem install amoeba
or add
gem 'amoeba'
to your Gemfile
then add the amoeba block to your model and run the dup method as usual
class Post < ActiveRecord::Base
has_many :comments
has_and_belongs_to_many :tags
amoeba do
enable
end
end
class Comment < ActiveRecord::Base
belongs_to :post
end
class Tag < ActiveRecord::Base
has_and_belongs_to_many :posts
end
class PostsController < ActionController
def some_method
my_post = Post.find(params[:id])
new_post = my_post.dup
new_post.save
end
end
Your new post should have all the tags that were originally associated with it, and all the comments should be duplicated as well. You can disable the duplication of various records through the DSL, which you can read about in the documentation, but for example, if you wanted to keep the tags, but not the comments you could do something like this:
class Post < ActiveRecord::Base
has_many :comments
has_and_belongs_to_many :tags
amoeba do
include_field :comments
end
end
or using the exclusive syntax
class Post < ActiveRecord::Base
has_many :comments
has_and_belongs_to_many :tags
amoeba do
exclude_field :comments
end
end
or by specifying which field types to recognize (and thusly copy)
class Post < ActiveRecord::Base
has_many :comments
has_and_belongs_to_many :tags
amoeba do
recognize :has_and_belongs_to_many
end
end
each of these various options should result in re-associating the new post with the same tags as the old post, but without duplicating the comments.
Amoeba will also automatically recurse in to child records if you enable them
class Post < ActiveRecord::Base
has_many :comments
amoeba do
enable
end
end
class Comment < ActiveRecord::Base
belongs_to :post
has_many :ratings
amoeba do
enable
end
end
class Rating < ActiveRecord::Base
belongs_to :comment
end
You can also prefix fields with some extra data to indicate uniqueness
class Post < ActiveRecord::Base
has_many :comments
amoeba do
enable
prepend :title => "Copy of "
end
end
and in addition to prepend you can also append to or run a regex on a given field
Enjoy! :)
You'd need to write your own clone_with_associations method which goes through a specific listed set of associations. Theoretically you could write something generic which uses reflect_on_all_associations but you would need to do the same on the associated objects, and this would inevitably end up creating a loop that generates an infinite amount of records.
So, just write your own. Something like
#in Blerg
has_many :foos
has_many :bars #bars also have many chickens which we want to copy over as well
def clone_with_associations
new_blerg = self.dup
new_blerg.save
#simple association
new_blerg.foos = self.foos
#two-level association
self.bars.each do |bar|
new_bar = bar.clone
new_bar.save
new_bar.chickens = bar.chickens
new_blerg.bars << bar
end
new_blerg
end
Now you can do
@new_blerg = Blerg.find(1).clone_with_associations
Equally, this gem seems to work well: https://github.com/moiristo/deep_cloneable, and is pretty easy to use.
Just
gem ‘deep_cloneable’, ‘~> 1.4.0’
and then:
pirate.deep_clone :include => :mateys
