rethinkdb-orm
RethinkDB ORM for Crystal Lang
Extending ActiveModel for attribute definitions, callbacks and validations
Configuration
# Below is the list of settings exposed by RethinkORM and their defaults
RethinkORM::Settings.configure do |settings|
settings.host = ENV["RETHINKDB_HOST"]? || "localhost"
settings.port = (ENV["RETHINKDB_PORT"]? || 28015).to_i
settings.db = ENV["RETHINKDB_DB"]? || ENV["RETHINKDB_DATABASE"]? || "test"
settings.user = ENV["RETHINKDB_USER"]? || "admin"
settings.password = ENV["RETHINKDB_PASSWORD"]? || ""
settings.lock_expire = (ENV["RETHINKDB_LOCK_EXPIRE"]? || 30).to_i.seconds
settings.lock_timeout = (ENV["RETHINKDB_LOCK_TIMEOUT"]? || 5).to_i.seconds
settings.retry_interval = (ENV["RETHINKDB_TIMEOUT"]? || 2).to_i.seconds
# Driver level reconnection attempts
settings.retry_attempts = ENV["RETHINKDB_RETRIES"]?.try(&.to_i) || 10
# ORM level query retries
settings.query_retries = ENV["RETHINKDB_QUERY_RETRIES"]?.try &.to_i || 10
end
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
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
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
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.
Indexes
Set secondary indexes with secondary_index
Parameter | |
----------- | --------------------------------------------- |
attribute
| defines the field on which to create an index |
Changefeeds
Access the changefeed of a document or table through the changes
query.
Defaults to watch for events on a table if no id provided.
Parameter | | Default
--------- | ----------------------------------- | -------
id
| id of document to watch for changes | nil
Returns an iterator that emits NamedTuple(value: T, event: Event)
Changefeed::Event::Deleted
events yield the deleted modelChangefeed::Event::Created
events yield the created modelChangefeed::Event::Updated
events yield the updated model
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 |change|
game = change.value
puts "looks like the score is #{game.score}" unless game.nil?
end
end
# Observe changes on a table
spawn do
Game.changes.each do |change|
game = change.value
puts "#{game.type}: #{game.score}" unless game.nil?
puts "game event: #{change.event}"
end
end
Validations
Builds on active-model's validation
ensure_unique
Fails to validate if field with duplicate value present in db. If scope is set, the callback/block signature must be a tuple with types matching that of the scope. The field(s) are set with the result of the transform block upon successful validation
Parameter | | Default
----------------------- | ------------------------------------------------------- | -------
field
| Model attribute on which to guarantee uniqueness |
scope
| Attributes passed to the transform, defaults to :field | nil
create_index
| Whether or not to generate a secondary index | true
callback : T -> T
| Optional function to transform field value | nil
block : T -> T
| Optional block to transform field value before querying | nil
Timestamps
Adds creates created_at
and updated_at
attributes.
updated_at
is set through thebefore_update
callback, and initially set in thebefore_save
callback.created_at
is set through thebefore_create
callback.
The generated timestamp is UTC.
class Timo < RethinkORM::Base
# Simply include the module
include RethinkORM::Timestamps
attribute name : String
end