MongoMapper - Mapping Ruby To and From Mongo

Presentation at MongoChicago 2010 on mapping MongoDB to and from Ruby using MongoMapper.

Transcript

1. Ordered List John Nunemaker Mongo Chicago October 20, 2010 MongoMapper Mapping Ruby To and From Mongo
2. Using Extending Prophesying
3. Using Extending Prophesying
5. class Item end
6. class Item include MongoMapper::Document end
7. class Datum include MongoMapper::EmbeddedDocument end
8. Free Stuff
9. Free Stuff Persistence
10. Free Stuff Persistence Validations [presence, length, inclusion, ...]
11. Free Stuff Persistence Validations [presence, length, inclusion, ...] Callbacks [before/after validate, create, save, ...]
12. Free Stuff Persistence Validations [presence, length, inclusion, ...] Callbacks [before/after validate, create, save, ...] Associations [many, belongs_to, one, ...]
13. Free Stuff Persistence Validations [presence, length, inclusion, ...] Callbacks [before/after validate, create, save, ...] Associations [many, belongs_to, one, ...] Serialization [to_json]
14. Persistence Never gonna give you up
15. item = Item.create({ :title => 'MongoSF', :location => 'San Fran', :when => Time.now })
16. puts item.to_mongo { "_id" => ObjectID('4bd8cc5cbcd1b313b3000001'), "title" => "MongoSF", "location" => "San Fran", "when" => Wed Apr 28 17:01:32 -0700 2010 }
17. item = Item.new item[:title] = 'MongoSF' item[:location] = 'San Fran' item[:when] = Time.now item.save
18. puts item.to_mongo { "_id" => ObjectID('4bd8cc5cbcd1b313b3000001'), "title" => "MongoSF", "location" => "San Fran", "when" => Wed Apr 28 17:01:32 -0700 2010 }
19. Types What you be baby boo?
20. class Item include MongoMapper::Document key :title, String key :path, String end
21. But Mongo is Schema-less?
22. Think App Schema Instead of database schema
23. Built-in Types Array, Binary, Boolean, Date, Float, Hash, Integer, Nil, ObjectId, Set, String, Time
24. Custom Types Its shake and bake and I helped!
25. class Set def self.to_mongo(value) value.to_a end def self.from_mongo(value) Set.new(value || []) end end
26. class DowncasedString def self.to_mongo(value) value.nil? ? nil : value.to_s.downcase end def self.from_mongo(value) DowncasedString.to_mongo(value) end end
27. class User include MongoMapper::Document key :email, DowncasedString end
28. Typeless I do not know who I am
29. class Foo include MongoMapper::Document key :bar end foo = Foo.new foo.bar = 'Some text' # foo.bar => "Some text" foo.bar = 24 # foo.bar => 24
30. Validations Currently using fork of validatable
31. class Item include MongoMapper::Document key :title, String validates_presence_of :title end
32. class Item include MongoMapper::Document key :title, String, :required => true end
33. validates_presence_of validates_length_of validates_format_of validates_numericality_of validates_acceptance_of validates_confirmation_of validates_inclusion_of validates_exclusion_of
34. Callbacks Ripped from AS2’s cold, dead fingers
35. class Item include MongoMapper::Document key :title, String key :path, String key :parent_id, ObjectId belongs_to :parent before_validation :set_path private def set_path self.path = parent.path + title.parameterize end end
36. :before_save, :after_save, :before_create, :after_create, :before_update, :after_update, :before_validation, :after_validation, :before_validation_on_create, :after_validation_on_create, :before_validation_on_update, :after_validation_on_update, :before_destroy, :after_destroy, :validate_on_create, :validate_on_update, :validate
37. Scopes Plucky Power!
38. class User include MongoMapper::Document scope :johns, where(:name => 'John') end User.johns.all User.johns.first
39. class User include MongoMapper::Document scope :by_ages, lambda { |low, high| where(:age.gte => low, :age.lte => high) } end User.by_ages(13, 19).count User.by_ages(13, 19).all
40. class User include MongoMapper::Document scope :teen, where(:age.gte => 13, :age.lte => 19) def self.by_tag(tag) where(:tags => tag) end end User.teen.by_tag('bieber').count User.by_tag('bieber').teen.all
41. Associations I belong to you
42. to Docs belongs_to, one, many, many :in
43. class Account include MongoMapper::Document many :sites end class Site include MongoMapper::Document key :account_id, ObjectId belongs_to :account end
44. account = Account.create(:title => 'OL', :sites => [ Site.new(:title => 'OL', :domain => 'orderedlist.com'), Site.new(:title => 'RT', :domain => 'railstips.org'), ])
45. [ { '_id' => ObjectID('...'), 'title' => 'OL', 'domain' => 'orderedlist.com' 'account_id' => ObjectID('...'), }, { '_id' => ObjectID('...'), 'title' => 'RT', 'domain' => 'railstips.org' 'account_id' => ObjectID('...'), } ]
46. to Embedded Docs many, one
47. class Item include MongoMapper::Document many :data end class Datum include MongoMapper::EmbeddedDocument key :key, String key :value end
48. Item.create(:title => 'MongoSF', :data => [ Datum.new(:key => 'description', :value => 'Awesome.') ])
49. { '_id' => ObjectID('...'), 'title' => 'MongoSF', 'data' => [ { '_id' => ObjectID('...'), 'key' => 'description' 'value' => 'Awesome.', } ] }
50. Using Extending Prophesying
51. Plugins Conventional way to extend
52. Powered by Plugins MongoMapper is associations, callbacks, clone, descendants, dirty, equality, identity_map, inspect, keys, logger, modifiers, pagination, persistence, protected, rails, serialization, timestamps, userstamps, validations
55. module MongoMapper module Plugins def plugins @plugins ||= [] end def plugin(mod) extend mod::ClassMethods if mod.const_defined?(:ClassMethods) include mod::InstanceMethods if mod.const_defined?(:InstanceMethods) mod.configure(self) if mod.respond_to?(:configure) plugins << mod end end end
56. module ActsAsListFu module ClassMethods def reorder(ids) # reorder ids... end end module InstanceMethods def move_to_top # move to top end end def self.configure(model) model.key :position, Integer, :default => 1 end end
57. class Foo include MongoMapper::Document plugin ActsAsListFu end Foo.reorder(...) Foo.new.move_to_top
58. Good Example Joint: github.com/jnunemaker/joint
59. class Asset include MongoMapper::Document plugin Joint attachment :image attachment :file end
60. asset = Asset.create({ :image => File.open('john.jpg', 'r'), :file => File.open('foo.txt', 'r'), }) asset.image.id asset.image.name asset.image.type asset.image.size asset.image.read
61. Descendant Appends Fancy Schmancy and Stolen
62. module FancySchmancy def some_method puts 'some method' end end MongoMapper::Document.append_extensions(FancySchmancy) class Foo include MongoMapper::Document end Foo.some_method # puts 'some method' Foo.new.some_method # NoMethodError
63. module FancySchmancy def some_method puts 'some method' end end MongoMapper::Document.append_inclusions(FancySchmancy) class Foo include MongoMapper::Document end Foo.new.some_method # puts 'some method' Foo.some_method # NoMethodError
64. module FancySchmancy def some_method puts 'some method' end end class Foo include MongoMapper::Document end MongoMapper::Document.append_extensions(FancySchmancy) class Bar include MongoMapper::Document end Foo.some_method # puts 'some method' Bar.some_method # puts 'some method'
65. module IdentityMapAddition def self.included(model) model.plugin MongoMapper::Plugins::IdentityMap end end MongoMapper::Document.append_inclusions(IdentityMapAddition)
66. Using Extending Prophesying
67. Active Model rails3 branch
68. Documentation http://mongomapper.com
69. “ Brian Ford @brixen Documentation: n. paradoxically repeating yourself so you do not need to repeat yourself.
72. Ordered List Thank you! john@orderedlist.com John Nunemaker Mongo Chicago October 20, 2010 @jnunemaker