Question

I am creating an app for uploading and sharing files between users.
I have User and Files models and have created a third File_Sharing_Relationships model which contains a sharer_id, file_id and shared_with_id columns. I want to be able to create the following methods:

     @upload.file_sharing_relationships - lists users that the file is shared with
     @user.files_shared_with -  lists files that are shared with the user.
     @user.files_shared - lists files that the user is sharing with others
     @user.share_file_with - creates a sharing relationship

Are there any rails associations, such as ‘polymorphic’ that I could be using to make these relationships?

Any suggestions appreciated. Thanks.

Answer 1

All you need to do is to read Rails Guides and apply all what you learn.

Basically you need to store info about:

• user who created a “sharing”
• user or group or whatever is a target of a sharing action
• resource that is being shared

So:

class SharedItem < ActiveRecord::Base
      belongs_to :sharable, :polymorphic => true #this is user, please think of better name than "sharable"...
      belongs_to :resource, :polymorphic => true #can be your file
      belongs_to :user
end

You need SharedItem to have:

user_id: integer, sharable_id: integer, sharable_type: string, resource_id: integer, resource_type: string

Then you can get “methods” you specified by writing named scopes like:

named_scope :for_user, lambda {|user| {:conditions => {:user_id => user.id} }}

or by specifying proper associations:

class File < ActiveRecord::Base
  has_many :shared_items, :as => :resource, :dependent => :destroy
end