serialize_has_many

Serializes has_many relationships into a single column while still doing attributes, validations, callbacks, nested forms and fields_for. Easy NoSQL with ActiveRecord!

Installation

Add this line to your application's Gemfile:

gem 'serialize_has_many'

And then execute:

$ bundle

Or install it yourself as:

$ gem install serialize_has_many

Usage

Assume you have a Parent has-many Child relation. To use serialize_has_many:

• Child should respond to attributes and new(attributes). To be clear:
  • child.attributes should give a hash
  • Child.new(attributes) should take that hash
• Parent should have an attribute to store the serialized data, preferably text datatype
• Add serialize_has_many in the Parent

Example

(For a real scenario, check example/app/models/)

# Make Child to use ActiveModel::Model instead of ActiveRecord
class Child
  include ActiveModel::Model
  attr_accessor :name, :age, ...
  validates ...

  def attributes
    { name: name, age: age, ... }
  end
end

# Convert Parent to use serialize_has_many instead of has_many
class Parent < ActiveRecord::Base
  include SerializeHasMany::Concern
  serialize_has_many "<name of column>",
    Child, # Child class
    using: JSON, # JSON, YAML, or any other ActiveRecord serializer
    validate: false, # Set true to validate children when validating the parent
    reject_if: Proc.new { ... } # Proc to reject empty children when submitting from nested forms
end

Works With

• Tested on Rails 4.0 and above, Ruby 1.9.3+
• For the Child model, you can use any class that you want, as long as attributes provides a hash, and new(attributes) takes that hash. Some options are:
  • ActiveModel
  • Virtus
  • ActiveAttr

Advanced Scenarios

This gem supports nested relationships in the Child class. You can do it yourself with a simple array attribute, or you can use Virtus which allows you to have explicit nested object types. Just remember that attributes should provide a hash (and only a hash, no nested objects), and new(attributes) should take the same hash.

Contributing

1. Fork it ( https://github.com/rdsubhas/serialize_has_many/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request