Module: Lotus::Repository::ClassMethods

Defined in:
lib/lotus/repository.rb

Overview

Since:

  • 0.1.0

Instance Method Summary collapse

Instance Method Details

#adapter=(adapter) ⇒ Object

Assigns an adapter.

Lotus::Model is shipped with two adapters:

* SqlAdapter
* MemoryAdapter

Examples:

Memory adapter

require 'lotus/model'
require 'lotus/model/adapters/memory_adapter'

mapper = Lotus::Model::Mapper.new do
  # ...
end

adapter = Lotus::Model::Adapters::MemoryAdapter.new(mapper)

class UserRepository
  include Lotus::Repository
end

UserRepository.adapter = adapter

SQL adapter with a Sqlite database

require 'sqlite3'
require 'lotus/model'
require 'lotus/model/adapters/sql_adapter'

mapper = Lotus::Model::Mapper.new do
  # ...
end

adapter = Lotus::Model::Adapters::SqlAdapter.new(mapper, 'sqlite://path/to/database.db')

class UserRepository
  include Lotus::Repository
end

UserRepository.adapter = adapter

SQL adapter with a Postgres database

require 'pg'
require 'lotus/model'
require 'lotus/model/adapters/sql_adapter'

mapper = Lotus::Model::Mapper.new do
  # ...
end

adapter = Lotus::Model::Adapters::SqlAdapter.new(mapper, 'postgres://host:port/database')

class UserRepository
  include Lotus::Repository
end

UserRepository.adapter = adapter

Parameters:

  • adapter (Object) —

    an object that implements ‘Lotus::Model::Adapters::Abstract` interface

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 211

def adapter=(adapter)
  @adapter = adapter
end

#all ⇒ Array<Object>

Returns all the persisted entities.

Examples:

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

ArticleRepository.all # => [ #<Article:0x007f9b19a60098> ]

Returns:

  • (Array<Object>) —

    the result of the query

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 408

def all
  @adapter.all(collection)
end

#clear ⇒ Object

Deletes all the records from the current collection.

If used with a SQL database it executes a ‘DELETE FROM <table>`.

Examples:

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

ArticleRepository.clear # deletes all the records

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 507

def clear
  @adapter.clear(collection)
end

#create(entity) ⇒ Object

Creates a record in the database for the given entity. It assigns the ‘id` attribute, in case of success.

If already persisted (‘id` present) it does nothing.

Examples:

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

article = Article.new(title: 'Introducing Lotus::Model')
article.id # => nil

ArticleRepository.create(article) # creates a record
article.id # => 23

ArticleRepository.create(article) # no-op

Parameters:

  • entity (#id, #id=) —

    the entity to create

Returns:

  • (Object) —

    the entity

See Also:

  • Lotus::Repository#persist

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 286

def create(entity)
  unless _persisted?(entity)
    _touch(entity)
    @adapter.create(collection, entity)
  end
end

#delete(entity) ⇒ Object

Deletes a record in the database corresponding to the given entity.

If not already persisted (‘id` present) it raises an exception.

Examples:

With a persisted entity

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

article = ArticleRepository.find(23)
article.id # => 23

ArticleRepository.delete(article) # deletes the record

With a non persisted entity

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

article = Article.new(title: 'Introducing Lotus::Model')
article.id # => nil

ArticleRepository.delete(article) # raises Lotus::Model::NonPersistedEntityError

Parameters:

  • entity (#id) —

    the entity to delete

Returns:

  • (Object) —

    the entity

Raises:

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 384

def delete(entity)
  if _persisted?(entity)
    @adapter.delete(collection, entity)
  else
    raise Lotus::Model::NonPersistedEntityError
  end

  entity
end

#find(id) ⇒ Object, NilClass

Finds an entity by its identity.

If used with a SQL database, it corresponds to the primary key.

Examples:

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

ArticleRepository.find(23)   # => #<Article:0x007f9b19a60098>
ArticleRepository.find(9999) # => nil

Parameters:

  • id (Object) —

    the identity of the entity

Returns:

  • (Object, NilClass) —

    the result of the query, if present

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 431

def find(id)
  @adapter.find(collection, id)
end

#first ⇒ Object?

Returns the first entity in the database.

Examples:

With at least one persisted entity

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

ArticleRepository.first # => #<Article:0x007f8c71d98a28>

With an empty collection

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

ArticleRepository.first # => nil

Returns:

  • (Object, nil) —

    the result of the query

See Also:

  • Lotus::Repository#last

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 460

def first
  @adapter.first(collection)
end

#last ⇒ Object?

Returns the last entity in the database.

Examples:

With at least one persisted entity

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

ArticleRepository.last # => #<Article:0x007f8c71d98a28>

With an empty collection

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

ArticleRepository.last # => nil

Returns:

  • (Object, nil) —

    the result of the query

See Also:

  • Lotus::Repository#last

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 489

def last
  @adapter.last(collection)
end

#persist(entity) ⇒ Object

Creates or updates a record in the database for the given entity.

Examples:

With a non persisted entity

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

article = Article.new(title: 'Introducing Lotus::Model')
article.id # => nil

ArticleRepository.persist(article) # creates a record
article.id # => 23

With a persisted entity

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

article = ArticleRepository.find(23)
article.id # => 23

article.title = 'Launching Lotus::Model'
ArticleRepository.persist(article) # updates the record

article = ArticleRepository.find(23)
article.title # => "Launching Lotus::Model"

Parameters:

  • entity (#id, #id=) —

    the entity to persist

Returns:

  • (Object) —

    the entity

See Also:

  • Lotus::Repository#create
  • Lotus::Repository#update

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 254

def persist(entity)
  _touch(entity)
  @adapter.persist(collection, entity)
end

#transaction(options = {}) ⇒ Object

Wraps the given block in a transaction.

For performance reasons the block isn’t in the signature of the method, but it’s yielded at the lower level.

Please note that it’s only supported by some databases. For this reason, the accepted options may be different from adapter to adapter.

For advanced scenarios, please check the documentation of each adapter.

Examples:

Basic usage with SQL adapter

require 'lotus/model'

class Article
  include Lotus::Entity
  attributes :title, :body
end

class ArticleRepository
  include Lotus::Repository
end

article = Article.new(title: 'Introducing transactions',
  body: 'lorem ipsum')

ArticleRepository.transaction do
  ArticleRepository.dangerous_operation!(article) # => RuntimeError
  # !!! ROLLBACK !!!
end

Parameters:

  • options (Hash) (defaults to: {}) —

    options for transaction

See Also:

Since:

  • 0.2.3



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# File 'lib/lotus/repository.rb', line 548

def transaction(options = {})
  @adapter.transaction(options) do
    yield
  end
end

#update(entity) ⇒ Object

Updates a record in the database corresponding to the given entity.

If not already persisted (‘id` present) it raises an exception.

Examples:

With a persisted entity

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

article = ArticleRepository.find(23)
article.id # => 23
article.title = 'Launching Lotus::Model'

ArticleRepository.update(article) # updates the record

With a non persisted entity

require 'lotus/model'

class ArticleRepository
  include Lotus::Repository
end

article = Article.new(title: 'Introducing Lotus::Model')
article.id # => nil

ArticleRepository.update(article) # raises Lotus::Model::NonPersistedEntityError

Parameters:

  • entity (#id) —

    the entity to update

Returns:

  • (Object) —

    the entity

Raises:

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/repository.rb', line 335

def update(entity)
  if _persisted?(entity)
    _touch(entity)
    @adapter.update(collection, entity)
  else
    raise Lotus::Model::NonPersistedEntityError
  end
end