Couchbase Model

This library allows to declare models for couchbase gem.

SUPPORT

If you found an issue, please file it in our JIRA. Also you are always welcome on #libcouchbase channel at freenode.net IRC servers.

Documentation: http://rdoc.info/gems/couchbase-model

Rails integration

To generate config you can use rails generate couchbase:config:

$ rails generate couchbase:config
create  config/couchbase.yml

It will generate this config/couchbase.yml for you:

common: &common
  hostname: localhost
  port: 8091
  username:
  password:
  pool: default

development:
  <<: *common
  bucket: couchbase_tinyurl_development

test:
  <<: *common
  bucket: couchbase_tinyurl_test

# set these environment variables on your production server
production:
  hostname: <%= ENV['COUCHBASE_HOST'] %>
  port: <%= ENV['COUCHBASE_PORT'] %>
  username: <%= ENV['COUCHBASE_USERNAME'] %>
  password: <%= ENV['COUCHBASE_PASSWORD'] %>
  pool: <%= ENV['COUCHBASE_POOL'] %>
  bucket: <%= ENV['COUCHBASE_BUCKET'] %>

Examples

require 'couchbase/model'

class Post < Couchbase::Model
  attribute :title
  attribute :body
  attribute :draft
end

p = Post.new(:id => 'hello-world',
             :title => 'Hello world',
             :draft => true)
p.save
p = Post.find('hello-world')
p.body = "Once upon the times...."
p.save
p.update(:draft => false)
Post.bucket.get('hello-world')  #=> {"title"=>"Hello world", "draft"=>false,
                                #    "body"=>"Once upon the times...."}

You can also let the library generate the unique identifier for you:

p = Post.create(:title => 'How to generate ID',
                :body => 'Open up the editor...')
p.id        #=> "74f43c3116e788d09853226603000809"

There are several algorithms available. By default it use :sequential algorithm, but you can change it to more suitable one for you:

class Post < Couchbase::Model
  attribute :title
  attribute :body
  attribute :draft

  uuid_algorithm :random
end

You can define connection options on per model basis:

class Post < Couchbase::Model
  attribute :title
  attribute :body
  attribute :draft

  connect :port => 80, :bucket => 'blog'
end

Validations

There are all methods from ActiveModel::Validations accessible in context of rails application:

class Comment < Couchbase::Model
  attribute :author, :body

  validates_presence_of :author, :body
end

Views (aka Map/Reduce indexes)

Views are stored in models directory in subdirectory named after the model (to be precious design_document attribute of the model class). Here is an example of directory layout for Link model with three views.

.
└── app
    └── models
        ├── link
        │   ├── total_count
        │   │   ├── map.js
        │   │   └── reduce.js
        │   ├── by_created_at
        │   │   └── map.js
        │   └── by_view_count
        │       └── map.js
        └── link.rb

To generate view you can use yet another generator rails generate couchbase:view DESIGNDOCNAME VIEWNAME. For example how total_count view could be generated:

$ rails generate couchbase:view link total_count

The generated files contains useful info and links about how to write map and reduce functions, you can take a look at them in the templates directory.

In the model class you should declare accessible views:

class Post < Couchbase::Model
  attribute :title
  attribute :body
  attribute :draft
  attribute :view_count
  attribute :created_at, :default => lambda { Time.now }

  view :total_count, :by_created_at, :by_view_count
end

And request them later:

Post.by_created_at(:include_docs => true).each do |post|
  puts post.title
end

Post.by_view_count(:include_docs => true).group_by(&:view_count) do |count, posts|
  p "#{count} -> #{posts.map{|pp| pp.inspect}.join(', ')}"
end

couchbase-model