Warning
Development work as stopped as we don't use SimplyStored anymore. Please do not expect any future commits and fixes.
Introduction
Convenience layer for CouchDB on top of CouchPotato.
SimplyStored allows you to persist your objects to CouchDB using an ActiveRecord-like syntax.
In contrast to CouchPotato (on top of it is build) it supports associations and other syntactic sugar that makes ActiveRecord so appealing.
SimplyStored has also support for S3 attachments.
See also RockingChair on how to speed-up your unit tests by using an in-memory CouchDB backend.
More examples on how to work with SimplyStored can be found here
Installation
gem install simply_stored
Using with Rails
Create a config/couchdb.yml:
default: &default
validation_framework: :active_model # optional
split_design_documents_per_view: true # optional
development:
<<: *default
database: http://localhost:5984/development_db
test:
<<: *default
database: http://localhost:5984/test_db
production:
<<: *default
database: <%= ENV['DB_NAME'] %>
Rails 2.x
In config/environment.rb:
config.gem 'simply_stored', :source => 'http://gemcutter.org'
config.frameworks -= [:active_record] # if you do not need ActiveRecord any more
Please note that if you use Rails 2.x, you can only use SimplyStored until version 0.5.4. SimplyStored 0.6 and above require Rails 3.x.
Rails 3.x
Add to your Gemfile:
# gem 'rails' # we don't want to load activerecord so we can't require rails
gem 'railties'
gem 'actionpack'
gem 'actionmailer'
gem 'activemodel'
gem 'simply_stored', :require => 'simply_stored/couch'
Please also see the installation info of CouchPotato
Usage
Require SimplyStored:
require 'simply_stored'
CouchPotato::Config.database_name = "http://example.com:5984/name_of_the_db"
From now on you can define classes that use SimplyStored.
Intro
SimplyStored auto-generates views for you and handles all the serialization and de-serialization stuff.
class User
include SimplyStored::Couch
property :login
property :age
property :accepted_terms_of_service, :type => :boolean
property :last_login, :type => Time
end
user = User.new(:login => 'Bert', :age => 12, :accepted_terms_of_service => true, :last_login = Time.now)
user.save
User.find_by_age(12).login
# => 'Bert'
User.all
# => [user]
class Post
include SimplyStored::Couch
property :title
property :body
belongs_to :user
end
class User
has_many :posts
end
post = Post.create(:title => 'My first post', :body => 'SimplyStored is so nice!', :user => user)
user.posts
# => [post]
Post.find_all_by_title_and_user_id('My first post', user.id).first.body
# => 'SimplyStored is so nice!'
post.destroy
user.posts(:force_reload => true)
# => []
Associations
The supported associations are: belongs_to, has_one, has_many, has_many :through, and has_and_belongs_to_many:
class Post
include SimplyStored::Couch
property :title
property :body
has_many :posts, :dependent => :destroy
has_many :users, :through => :posts
belongs_to :user
end
class Comment
include SimplyStored::Couch
property :body
belongs_to :post
belongs_to :user
end
post = Post.create(:title => 'Look ma!', :body => 'I can have comments')
mike = User.create(:login => 'mike')
mikes_comment = Comment.create(:user => mike, :post => post, :body => 'Wow, comments are nice')
john = User.create(:login => 'john')
johns_comment = Comment.create(:user => john, :post => post, :body => 'They are indeed')
post.comments
# => [mikes_comment, johns_comment]
post.comments(:order => :desc)
# => [johns_comment, mikes_comment]
post.comments(:limit => 1)
# => [mikes_comment]
post.comment_count
# => 2
post.users
# => [mike, john]
post.user_count
# => 2
n:m relations where the IDs are stored on one part as an array:
class Server
include SimplyStored::Couch
property :hostname
has_and_belongs_to_many :networks, :storing_keys => true
end
class Network
include SimplyStored::Couch
property :klass
has_and_belongs_to_many :servers, :storing_keys => false
end
network = Network.create(:klass => "A")
server = Server.new(:hostname => 'www.example.com')
network.add_server(server)
server.network_ids # => [network.id]
network.servers # => [server]
server.networks # => [network]
The array property holding the IDs of the other item will be used to constuct two view to lookup the other part. Soft deleting is only supported on the class holding the IDs.
Custom Associations
class Document
include SimplyStored::Couch
belongs_to :creator, :class_name => "User"
belongs_to :updater, :class_name => "User"
end
d = Document.new
d.creator = User.first
Validations
Further, you can have validations (using the validatable gem)
class Project
include SimplyStored::Couch
property :title
property :budget
property :deadline, :type => Time
property :priority
validates_presence_of :budget
validates_uniqueness_of :priority
validates_format_of :title, :with => /\A[a-z0-9\-']+\Z/, :allow_blank => true
validates_inclusion_of :priority, :in => [0,1,2,3,4,5]
end
project = Project.new
project.save
# => false
project.errors
# => #<Validatable::Errors:0x102592740 @errors={:budget=>["can't be empty"], :priority=>["must be one or more of 0, 1, 2, 3, 4, 5"]}
project.save!
# => raises CouchPotato::Database::ValidationsFailedError: #<CouchPotato::Database::ValidationsFailedError:0x102571130>
S3 Attachments
SimplyStored supports storing large attachments in Amazon S3. It uses RightAWS for the interaction with the EC2 API:
class Log
include SimplyStored::Couch
has_s3_attachment :data, :bucket => 'the-bucket-name',
:access_key => 'my-AWS-key-id',
:secret_access_key => 'psst!-secret',
:location => :eu,
:after_delete => :delete,
:logger => Logger.new('/dev/null')
end
log = Log.new
log.data = File.read('/var/log/messages')
log.save
# => true
log.data_size
# => 11238132
This will create an item on S3 in the specified bucket. The item will use the ID of the log object as the key and the body will be the data attribute. This way you can store big files outside of CouchDB.
Soft delete
SimplyStored also has support for "soft deleting" - much like acts_as_paranoid. Items will then not be deleted but only marked as deleted. This way you can recover them later.
class Document
include SimplyStored::Couch
property :title
enable_soft_delete # will use :deleted_at attribute by default
end
doc = Document.create(:title => 'secret project info')
Document.find_all_by_title('secret project info')
# => [doc]
doc.destroy
Document.find_all_by_title('secret project info')
# => []
Document.find_all_by_title('secret project info', :with_deleted => true)
# => [doc]
CouchDB - Auto resolution of conflicts on save
SimplyStored now by default retries conflicted save operations if it is possible to resolve the conflict. Solving the conflict means that if updated were done one different attributes the local object will refresh those attributes and try to save again. This will be tried two times by default. Afterwards the conflict exception will be re-raised.
This feature can be controlled on the class level like this: User.auto_conflict_resolution_on_save = true | false
If auto_conflict_resolution_on_save is enabled, something like this will work:
class Document
include SimplyStored::Couch
property :title
property :content
end
original = Document.create(:title => 'version 1', :content => 'Hi there')
other_client = Document.find(original.id)
original.title = 'version 2'
original.save!
other_client.content = 'A better version'
other_client.save! # -> this line would fail without auto_conflict_resolution_on_save
other_client.title
# => 'version 2'
License
SimplyStored is licensed under the Apache 2.0 license. See LICENSE.txt
About
SimplyStored was written by Mathias Meyer and Jonathan Weiss for Peritor.