Module: Dynamoid::Associations::ClassMethods

Defined in:
lib/dynamoid/associations.rb

Instance Method Summary collapse

Instance Method Details

#belongs_to(name, options = {}) ⇒ Object

Declare a belongs_to association for this document.

class Post
  include Dynamoid::Document

  belongs_to :categories
end

Association supports following operations:

  • create

  • create!

  • delete

When a name of an associated class doesn't match an association name a class name should be specified explicitly either with class or class_name option:

belongs_to :item, class: Post
belongs_to :item, class_name: 'Post'

When associated class has own has_many or has_one association to the current class and the name doesn't match a name of the current class this name can be specified with inverse_of option:

class Category
  include Dynamoid::Document

  has_many :items, class_name: 'Post'
end

class Post
  include Dynamoid::Document

  belongs_to :categories, inverse_of: :items
end

By default a hash key attribute name is id. If an associated class uses another name for a hash key attribute it should be specified in the belongs_to association:

belongs_to :categories, foreign_key: :uuid

Parameters:

  • name (Symbol)

    the name of the association

  • options (Hash) (defaults to: {})

    options to pass to the association constructor

Options Hash (options):

  • :class (Class)

    the target class of the has_one association; that is, the has_many or has_one class

  • :class_name (String)

    the name of the target class of the association; that is, the name of the has_many or has_one class

  • :inverse_of (Symbol)

    the name of the association on the target class; that is, if the class has a has_many or has_one association, the name of that association

  • :foreign_key (Symbol)

    the name of a hash key attribute in the target class

Since:

  • 0.2.0


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# File 'lib/dynamoid/associations.rb', line 183

def belongs_to(name, options = {})
  association(:belongs_to, name, options)
end

#has_and_belongs_to_many(name, options = {}) ⇒ Object

Declare a has_and_belongs_to_many association for this document.

class Post
  include Dynamoid::Document

  has_and_belongs_to_many :tags
end

Association is an enumerable collection and supports following addition operations:

  • create

  • create!

  • destroy_all

  • delete_all

  • delete

  • <<

  • where

  • all

  • empty?

  • size

When a name of an associated class doesn't match an association name a class name should be specified explicitly either with class or class_name option:

has_and_belongs_to_many :labels, class: Tag
has_and_belongs_to_many :labels, class_name: 'Tag'

When associated class has own has_and_belongs_to_many association to the current class and the name doesn't match a name of the current class this name can be specified with inverse_of option:

class Tag
  include Dynamoid::Document

  has_and_belongs_to_many :items, class_name: 'Post'
end

class Post
  include Dynamoid::Document

  has_and_belongs_to_many :tags, inverse_of: :items
end

Parameters:

  • name (Symbol)

    the name of the association

  • options (Hash) (defaults to: {})

    options to pass to the association constructor

Options Hash (options):

  • :class (Class)

    the target class of the has_and_belongs_to_many association; that is, the belongs_to class

  • :class_name (String)

    the name of the target class of the association; that is, the name of the belongs_to class

  • :inverse_of (Symbol)

    the name of the association on the target class; that is, if the class has a belongs_to association, the name of that association

Since:

  • 0.2.0


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# File 'lib/dynamoid/associations.rb', line 239

def has_and_belongs_to_many(name, options = {})
  association(:has_and_belongs_to_many, name, options)
end

#has_many(name, options = {}) ⇒ Object

Declare a has_many association for this document.

class Category
  include Dynamoid::Document

  has_many :posts
end

Association is an enumerable collection and supports following addition operations:

  • create

  • create!

  • destroy_all

  • delete_all

  • delete

  • <<

  • where

  • all

  • empty?

  • size

When a name of an associated class doesn't match an association name a class name should be specified explicitly either with class or class_name option:

has_many :labels, class: Tag
has_many :labels, class_name: 'Tag'

When associated class has own belongs_to association to the current class and the name doesn't match a name of the current class this name can be specified with inverse_of option:

class Post
  include Dynamoid::Document

  belongs_to :item, class_name: 'Tag'
end

class Tag
  include Dynamoid::Document

  has_many :posts, inverse_of: :item
end

Parameters:

  • name (Symbol)

    the name of the association

  • options (Hash) (defaults to: {})

    options to pass to the association constructor

Options Hash (options):

  • :class (Class)

    the target class of the has_many association; that is, the belongs_to class

  • :class_name (String)

    the name of the target class of the association; that is, the name of the belongs_to class

  • :inverse_of (Symbol)

    the name of the association on the target class; that is, if the class has a belongs_to association, the name of that association

Since:

  • 0.2.0


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# File 'lib/dynamoid/associations.rb', line 80

def has_many(name, options = {})
  association(:has_many, name, options)
end

#has_one(name, options = {}) ⇒ Object

Declare a has_one association for this document.

class Image
  include Dynamoid::Document

  has_one :post
end

Association supports following operations:

  • create

  • create!

  • delete

When a name of an associated class doesn't match an association name a class name should be specified explicitly either with class or class_name option:

has_one :item, class: Post
has_one :item, class_name: 'Post'

When associated class has own belong_to association to the current class and the name doesn't match a name of the current class this name can be specified with inverse_of option:

class Post
  include Dynamoid::Document

  belongs_to :logo, class_name: 'Image'
end

class Image
  include Dynamoid::Document

  has_one :post, inverse_of: :logo
end

Parameters:

  • name (Symbol)

    the name of the association

  • options (Hash) (defaults to: {})

    options to pass to the association constructor

Options Hash (options):

  • :class (Class)

    the target class of the has_one association; that is, the belongs_to class

  • :class_name (String)

    the name of the target class of the association; that is, the name of the belongs_to class

  • :inverse_of (Symbol)

    the name of the association on the target class; that is, if the class has a belongs_to association, the name of that association

Since:

  • 0.2.0


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# File 'lib/dynamoid/associations.rb', line 128

def has_one(name, options = {})
  association(:has_one, name, options)
end