HasMagicFields

Allows the addition of custom "magic" fields and attributes on a per-model or per-parent-model basis. This is useful for situations where custom fields are required for a specific model or for multi-user, multi-account environments where accounts can customize attributes for subordinate models.

Installation

Add this line to your application's Gemfile:

gem 'has_magic_fields'

And then execute:

$ bundle

Create the migrations for MagicFileds and migrate:

rails g has_magic_fields:install
rake db:migrate

Usage

Model

Sprinkle a little magic into an existing model:

class Person < ActiveRecord::Base
  include HasMagicFields::Extend
  has_magic_fields
end

Add magic fields to your model:

@charlie = Person.create(:email => "charlie@example.com")
@charlie.create_magic_field(:name => "first_name")

Supply additional options if you have more specific requirements for your fields:

@charlie.create_magic_field(:name => "last_name", :is_required => true)
@charlie.create_magic_field(:name => "birthday", :datatype => :date)
@charlie.create_magic_field(:name => "salary", :default => "40000", :pretty_name => "Yearly Salary")

The :datatype option supports: :check_box_boolean, :date, :datetime, :integer

Use your new fields just like you would with any other ActiveRecord attribute:

@charlie.first_name = "Charlie"
@charlie.last_name = "Magic!"
@charlie.birthday = Date.today
@charlie.save

Find @charlie and inspect him:

@charlie = User.find(@charlie.id)
@charlie.first_name #=> "Charlie"
@charlie.last_name  #=> "Magic!"
@charlie.birthday #=> #<Date: 4908497/2,0,2299161>
@charlie.salary     #=> "40000", this is from :salary having a :default

Inherited Model

A child can inherit magic fields from a parent. To do this, declare the parent as having magic fields:

class Account < ActiveRecord::Base
  include HasMagicFields::Extend
  has_many :users
  has_magic_fields
end
@account = Account.create(:name => "BobCorp",:type_scoped => "User")

And declare the child as having magic fields :through the parent.

class User < ActiveRecord::Base
  include HasMagicFields::Extend
  belongs_to :account
  has_magic_fields :through => :account
end
@alice = User.create(:name => "alice", :account => @account)

To see all the magic fields available for a type_scoped(User) child from its parent:

@alice.magic_fields #=> [#<MagicColumn>,...]

To add magic fields, go through the parent or child:

@alice.create_magic_field(...)
@account.create_magic_field(…,:type_scoped => "User")

All User children for a given parent will have access to the same magic fields:

@alice.create_magic_field(:name => "salary")
@alice.salary = "40000"

@bob = User.create(:name => "bob", :account => @account)
# Magic! No need to add the column again!
@bob.salary = "50000"

###Different Model Inherited from The Samle Model the other modle Inherited from Account

class Product < ActiveRecord::Base
  include HasMagicFields::Extend
  belongs_to :account
  has_magic_fields :through => :account
end

@product = Product.create(:name => "car", :account => @account)

@product haven't salary magic field, @product.salary should raise NoMethodError

parent @account also haven't salary magic field

Get All Magic Fields

@account.magic_fields #get all meagic_fields both self and children
@account.magic_fields_with_scoped #get all meagic_fields self
@account.magic_fields_with_scoped("User") #get all meagic_fields User model

##To Do

Here's a short list of things that need to be done to polish up this gem:

• more data_type sppuort
• Benchmark and optimize

Maintainers

• Davy Zhou(ikeqiao)

Contributing

1. Fork it
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 new Pull Request

Credits

• Thank you to Brandon Keene for his original work making this plugin.
• Thank you to latortuga for his original work making this plugin. has_magic_fields