RethinkDB ORM for Crystal Lang

Extending ActiveModel for attribute definitions, callbacks and validations

Callbacks

Register callbacks for save, update, create and destroy by setting the corresponding before/after callback handler.

class ModelWithCallbacks < RethinkORM::Base
  attribute address : String
  attribute age : Int32 = 10

  before_create :set_address
  after_update :set_age
  before_destroy do
    self.name = "joe"
  end

  def set_address
    self.address = "23"
  end

  def set_age
    self.age = 30
  end
end

Associations

Set associations with belongs_to, has_many and has_one.

Access children in parent by accessing the method correpsonding to the pluralised child. Children collection method name is generated by dumb pluralisation (appending an s). Optionally set children collection name in has_many by setting collection_name param.

The has_many association requires the belongs_to association on the child. By default, belongs_to creates a secondary index on the foreign key.

class Parent < RethinkORM::Base
  attribute name : String
  has_many Child, collection_name: "children"
end

class Child < RethinkORM::Base
  attribute age : Int32
  belongs_to Parent
  has_many Pet
end

class Pet < RethinkORM::Base
  attribute name : String
  belongs_to Child
end

parent = Parent.new(name: "Phil")
parent.children.empty? # => true

child = Child.new(age: 99)
child.pets.empty? # => true

belongs_to

Parameter | | Default -------------- | ------------------------------------------------------------- | ------- parent_class | The parent class who this class is dependent on | dependent | Sets destroy behaviour. One of :none, :destroy, :delete | :none create_index | Create a secondary index on the foreign key | true through | Sets a through relationship | nil

has_many

Parameter | | Default ----------------- | ----------------------------------------------------------------------------- | ------- child_class | The parent class who this class is dependent on | dependent | Sets destroy behaviour. One of :none, :destroy, :delete | :none collection_name | Define collection name, otherwise collection named through dumb pluralisation | nil through | Sets a through relationship | nil

has_one

Parameter | | Default ----------------- | ----------------------------------------------------------------------------- | ------- child_class | The parent class who this class is dependent on | dependent | Sets destroy behaviour. One of :none, :destroy, :delete | :none collection_name | Define collection name, otherwise collection named through dumb pluralisation | nil through | Sets a through relationship | nil

Dependency

dependent param in the association definition macros defines the fate of the association on model destruction.
Default is :none, :destroy and :delete ensure destruction of association dependents.

Through Relation

In progress..

Indexes

Set secondary indexes with secondary_index

Parameter | | ----------- | --------------------------------------------- | attribute | defines the field on which to create an index |

Changefeeds

In progress..

class Game < RethinkORM::Base
  attribute type : String
  attribute score : Int32, default: 0
end

ballgame = Game.create!(type: "footy")

# Observe changes on a single document
spawn do
  Game.changes(ballgame.id).each do |game|
    puts "looks like the score is #{game.score}"
  end
end

# Observe changes on a table
spawn do 
  Game.changes.each do |game|
    puts "#{game.type}: #{game.score}"
  end
end