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converted to Hash subclass

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This commit is contained in:
Chris Anderson 2008-10-02 10:45:08 -07:00
parent 2b7e49c9c6
commit 98923843ef
2 changed files with 286 additions and 311 deletions
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573
lib/couchrest/core/model.rb
View file

@ -8,8 +8,7 @@ module CouchRest
# #
# This is an example class using CouchRest::Model. It is taken from the spec/couchrest/core/model_spec.rb file, which may be even more up to date than this example. # This is an example class using CouchRest::Model. It is taken from the spec/couchrest/core/model_spec.rb file, which may be even more up to date than this example.
# #
# class Article # class Article < CouchRest::Model
# include CouchRest::Model
# use_database CouchRest.database!('http://localhost:5984/couchrest-model-test') # use_database CouchRest.database!('http://localhost:5984/couchrest-model-test')
# unique_id :slug # unique_id :slug
# #
@ -38,315 +37,291 @@ module CouchRest
# #
# before(:create, :generate_slug_from_title) # before(:create, :generate_slug_from_title)
# def generate_slug_from_title # def generate_slug_from_title
# doc['slug'] = title.downcase.gsub(/[^a-z0-9]/,'-').squeeze('-').gsub(/^\-|\-$/,'') # self['slug'] = title.downcase.gsub(/[^a-z0-9]/,'-').squeeze('-').gsub(/^\-|\-$/,'')
# end # end
# end # end
module Model class Model < Hash
# instantiates the hash by converting all the keys to strings.
def initialize keys = {}
super()
keys.each do |k,v|
self[k.to_s] = v
end
unless self['_id'] && self['_rev']
init_doc
end
end
class << self class << self
# this is the CouchRest::Database that model classes will use unless they override it with <tt>use_database</tt> # this is the CouchRest::Database that model classes will use unless they override it with <tt>use_database</tt>
attr_accessor :default_database attr_accessor :default_database
end
# instance methods on the model classes
module InstanceMethods
attr_accessor :doc
def initialize keys = {}
self.doc = {}
keys.each do |k,v|
doc[k.to_s] = v
end
unless doc['_id'] && doc['_rev']
init_doc
end
end
# returns the database used by this model's class
def database
self.class.database
end
# alias for doc['_id']
def id
doc['_id']
end
# alias for doc['_rev']
def rev
doc['_rev']
end
# returns true if the doc has never been saved
def new_record?
!doc['_rev']
end
# save the doc to the db using create or update
def save
if new_record?
create
else
update
end
end
protected
def create
set_unique_id if respond_to?(:set_unique_id) # hack
save_doc
end
def update
save_doc
end
private
def save_doc
result = database.save doc
if result['ok']
doc['_id'] = result['id']
doc['_rev'] = result['rev']
end
result['ok']
end
def init_doc
doc['type'] = self.class.to_s
end
end # module InstanceMethods
# Class methods for models that include CouchRest::Model
module ClassMethods
# override the CouchRest::Model-wide default_database # override the CouchRest::Model-wide default_database
def use_database db def use_database db
@database = db @database = db
end end
# returns the CouchRest::Database instance that this class uses
def database
@database || CouchRest::Model.default_database
end
# load a document from the database
def get id
doc = database.get id
new(doc)
end
# Defines methods for reading and writing from fields in the document. Uses key_writer and key_reader internally.
def key_accessor *keys
key_writer *keys
key_reader *keys
end
# For each argument key, define a method <tt>key=</tt> that sets the corresponding field on the CouchDB document.
def key_writer *keys
keys.each do |method|
key = method.to_s
define_method "#{method}=" do |value|
doc[key] = value
end
end
end
# For each argument key, define a method <tt>key</tt> that reads the corresponding field on the CouchDB document. # returns the CouchRest::Database instance that this class uses
def key_reader *keys def database
keys.each do |method| @database || CouchRest::Model.default_database
key = method.to_s end
define_method method do
doc[key]
end
end
end
# Automatically set <tt>updated_at</tt> and <tt>created_at</tt> fields on the document whenever saving occurs. CouchRest uses a pretty decent time format by default. See Time#to_json
def timestamps!
before(:create) do
doc['updated_at'] = doc['created_at'] = Time.now
end
before(:update) do
doc['updated_at'] = Time.now
end
end
# Name a method that will be called before the document is first saved, which returns a string to be used for the document's <tt>_id</tt>. Because CouchDB enforces a constraint that each id must be unique, this can be used to enforce eg: uniq usernames. Note that this id must be globally unique across all document types which share a database, so if you'd like to scope uniqueness to this class, you should use the class name as part of the unique id.
def unique_id method
define_method :set_unique_id do
doc['_id'] ||= self.send(method)
end
end
end # module ClassMethods
module MagicViews # load a document from the database
def get id
# Define a CouchDB view. The name of the view will be the concatenation of <tt>by</tt> and the keys joined by <tt>_and_</tt> doc = database.get id
# new(doc)
# ==== Example views: end
#
# class Post
# # view with default options
# # query with Post.by_date
# view_by :date, :descending => true
#
# # view with compound sort-keys
# # query with Post.by_user_id_and_date
# view_by :user_id, :date
#
# # view with custom map/reduce functions
# # query with Post.by_tags :reduce => true
# view_by :tags,
# :map =>
# "function(doc) {
# if (doc.type == 'Post' && doc.tags) {
# doc.tags.forEach(function(tag){
# emit(doc.tag, 1);
# });
# }
# }",
# :reduce =>
# "function(keys, values, rereduce) {
# return sum(values);
# }"
# end
#
# <tt>view_by :date</tt> will create a view defined by this Javascript function:
#
# function(doc) {
# if (doc.type == 'Post' && doc.date) {
# emit(doc.date, null);
# }
# }
#
# It can be queried by calling <tt>Post.by_date</tt> which accepts all valid options for CouchRest::Database#view. In addition, calling with the <tt>:raw => true</tt> option will return the view rows themselves. By default <tt>Post.by_date</tt> will return the documents included in the generated view.
#
# CouchRest::Database#view options can be applied at view definition time as defaults, and they will be curried and used at view query time. Or they can be overridden at query time.
#
# Custom views can be queried with <tt>:reduce => true</tt> to return reduce results. The default for custom views is to query with <tt>:reduce => false</tt>.
#
# Views are generated (on a per-model basis) lazily on first-access. This means that if you are deploying changes to a view, the views for that model won't be available until generation is complete. This can take some time with large databases. Strategies are in the works.
#
# To understand the capabilities of this view system more compeletly, it is recommended that you read the RSpec file at <tt>spec/core/model.rb</tt>.
def view_by *keys
opts = keys.pop if keys.last.is_a?(Hash)
opts ||= {}
type = self.to_s
method_name = "by_#{keys.join('_and_')}" # Defines methods for reading and writing from fields in the document. Uses key_writer and key_reader internally.
@@design_doc ||= default_design_doc def key_accessor *keys
key_writer *keys
if opts[:map] key_reader *keys
view = {} end
view['map'] = opts.delete(:map)
if opts[:reduce] # For each argument key, define a method <tt>key=</tt> that sets the corresponding field on the CouchDB document.
view['reduce'] = opts.delete(:reduce) def key_writer *keys
opts[:reduce] = false keys.each do |method|
end key = method.to_s
@@design_doc['views'][method_name] = view define_method "#{method}=" do |value|
else self[key] = value
doc_keys = keys.collect{|k|"doc['#{k}']"} end
key_protection = doc_keys.join(' && ') end
key_emit = doc_keys.length == 1 ? "#{doc_keys.first}" : "[#{doc_keys.join(', ')}]" end
map_function = <<-JAVASCRIPT
function(doc) { # For each argument key, define a method <tt>key</tt> that reads the corresponding field on the CouchDB document.
if (doc.type == '#{type}' && #{key_protection}) { def key_reader *keys
emit(#{key_emit}, null); keys.each do |method|
} key = method.to_s
} define_method method do
JAVASCRIPT self[key]
@@design_doc['views'][method_name] = { end
'map' => map_function end
} end
end
# Automatically set <tt>updated_at</tt> and <tt>created_at</tt> fields on the document whenever saving occurs. CouchRest uses a pretty decent time format by default. See Time#to_json
@@design_doc_fresh = false def timestamps!
before(:create) do
self.meta_class.instance_eval do self['updated_at'] = self['created_at'] = Time.now
define_method method_name do |*args| end
query = opts.merge(args[0] || {}) before(:update) do
query[:raw] = true if query[:reduce] self['updated_at'] = Time.now
unless @@design_doc_fresh end
refresh_design_doc end
end
raw = query.delete(:raw) # Name a method that will be called before the document is first saved, which returns a string to be used for the document's <tt>_id</tt>. Because CouchDB enforces a constraint that each id must be unique, this can be used to enforce eg: uniq usernames. Note that this id must be globally unique across all document types which share a database, so if you'd like to scope uniqueness to this class, you should use the class name as part of the unique id.
view_name = "#{type}/#{method_name}" def unique_id method
define_method :set_unique_id do
self['_id'] ||= self.send(method)
end
end
# Define a CouchDB view. The name of the view will be the concatenation of <tt>by</tt> and the keys joined by <tt>_and_</tt>
#
# ==== Example views:
#
# class Post
# # view with default options
# # query with Post.by_date
# view_by :date, :descending => true
#
# # view with compound sort-keys
# # query with Post.by_user_id_and_date
# view_by :user_id, :date
#
# # view with custom map/reduce functions
# # query with Post.by_tags :reduce => true
# view_by :tags,
# :map =>
# "function(doc) {
# if (doc.type == 'Post' && doc.tags) {
# doc.tags.forEach(function(tag){
# emit(doc.tag, 1);
# });
# }
# }",
# :reduce =>
# "function(keys, values, rereduce) {
# return sum(values);
# }"
# end
#
# <tt>view_by :date</tt> will create a view defined by this Javascript function:
#
# function(doc) {
# if (doc.type == 'Post' && doc.date) {
# emit(doc.date, null);
# }
# }
#
# It can be queried by calling <tt>Post.by_date</tt> which accepts all valid options for CouchRest::Database#view. In addition, calling with the <tt>:raw => true</tt> option will return the view rows themselves. By default <tt>Post.by_date</tt> will return the documents included in the generated view.
#
# CouchRest::Database#view options can be applied at view definition time as defaults, and they will be curried and used at view query time. Or they can be overridden at query time.
#
# Custom views can be queried with <tt>:reduce => true</tt> to return reduce results. The default for custom views is to query with <tt>:reduce => false</tt>.
#
# Views are generated (on a per-model basis) lazily on first-access. This means that if you are deploying changes to a view, the views for that model won't be available until generation is complete. This can take some time with large databases. Strategies are in the works.
#
# To understand the capabilities of this view system more compeletly, it is recommended that you read the RSpec file at <tt>spec/core/model.rb</tt>.
def view_by *keys
opts = keys.pop if keys.last.is_a?(Hash)
opts ||= {}
type = self.to_s
method_name = "by_#{keys.join('_and_')}"
@@design_doc ||= default_design_doc
if opts[:map]
view = {}
view['map'] = opts.delete(:map)
if opts[:reduce]
view['reduce'] = opts.delete(:reduce)
opts[:reduce] = false
end
@@design_doc['views'][method_name] = view
else
doc_keys = keys.collect{|k|"doc['#{k}']"}
key_protection = doc_keys.join(' && ')
key_emit = doc_keys.length == 1 ? "#{doc_keys.first}" : "[#{doc_keys.join(', ')}]"
map_function = <<-JAVASCRIPT
function(doc) {
if (doc.type == '#{type}' && #{key_protection}) {
emit(#{key_emit}, null);
}
}
JAVASCRIPT
@@design_doc['views'][method_name] = {
'map' => map_function
}
end
@@design_doc_fresh = false
self.meta_class.instance_eval do
define_method method_name do |*args|
query = opts.merge(args[0] || {})
query[:raw] = true if query[:reduce]
unless @@design_doc_fresh
refresh_design_doc
end
raw = query.delete(:raw)
view_name = "#{type}/#{method_name}"
view = fetch_view(view_name, query)
if raw
view
else
# TODO this can be optimized once the include-docs patch is applied
view['rows'].collect{|r|new(database.get(r['id']))}
end
end
end
end
private
def fetch_view view_name, opts
retryable = true
begin
database.view(view_name, opts)
# the design doc could have been deleted by a rouge process
rescue RestClient::ResourceNotFound => e
if retryable
refresh_design_doc
retryable = false
retry
else
raise e
end
end
end
def design_doc_id
"_design/#{self.to_s}"
end
def default_design_doc
{
"_id" => design_doc_id,
"language" => "javascript",
"views" => {}
}
end
def refresh_design_doc
saved = database.get(design_doc_id) rescue nil
if saved
@@design_doc['views'].each do |name, view|
saved['views'][name] = view
end
database.save(saved)
else
database.save(@@design_doc)
end
@@design_doc_fresh = true
end
end # class << self
view = fetch_view(view_name, query)
if raw
view
else
# TODO this can be optimized once the include-docs patch is applied
view['rows'].collect{|r|new(database.get(r['id']))}
end
end
end
end
private
def fetch_view view_name, opts
retryable = true
begin
database.view(view_name, opts)
# the design doc could have been deleted by a rouge process
rescue RestClient::ResourceNotFound => e
if retryable
refresh_design_doc
retryable = false
retry
else
raise e
end
end
end
def design_doc_id
"_design/#{self.to_s}"
end
def default_design_doc
{
"_id" => design_doc_id,
"language" => "javascript",
"views" => {}
}
end
def refresh_design_doc
saved = database.get(design_doc_id) rescue nil
if saved
@@design_doc['views'].each do |name, view|
saved['views'][name] = view
end
database.save(saved)
else
database.save(@@design_doc)
end
@@design_doc_fresh = true
end
end # module MagicViews
module Callbacks # returns the database used by this model's class
def self.included(model) def database
model.class_eval <<-EOS, __FILE__, __LINE__ self.class.database
include Extlib::Hook
register_instance_hooks :save, :create, :update #, :destroy
EOS
end
end # module Callbacks
# bookkeeping section
# load the code into the model class
def self.included(model)
model.send(:include, InstanceMethods)
model.extend ClassMethods
model.extend MagicViews
model.send(:include, Callbacks)
end end
end # module Model # alias for self['_id']
def id
self['_id']
end
# alias for self['_rev']
def rev
self['_rev']
end
# returns true if the self has never been saved
def new_record?
!rev
end
# save the doc to the db using create or update
def save
if new_record?
create
else
update
end
end
protected
def create
set_unique_id if respond_to?(:set_unique_id) # hack
save_doc
end
def update
save_doc
end
private
def save_doc
result = database.save self
if result['ok']
self['_id'] = result['id']
self['_rev'] = result['rev']
end
result['ok']
end
def init_doc
self['type'] = self.class.to_s
end
include ::Extlib::Hook
register_instance_hooks :save, :create, :update #, :destroy
end # class Model
end # module CouchRest end # module CouchRest

24
spec/couchrest/core/model_spec.rb
View file

@ -1,11 +1,10 @@
require File.dirname(__FILE__) + '/../../spec_helper' require File.dirname(__FILE__) + '/../../spec_helper'
class Basic class Basic < CouchRest::Model
include CouchRest::Model
end end
class Article class Article < CouchRest::Model
include CouchRest::Model
use_database CouchRest.database!('http://localhost:5984/couchrest-model-test') use_database CouchRest.database!('http://localhost:5984/couchrest-model-test')
unique_id :slug unique_id :slug
@ -34,7 +33,7 @@ class Article
before(:create, :generate_slug_from_title) before(:create, :generate_slug_from_title)
def generate_slug_from_title def generate_slug_from_title
doc['slug'] = title.downcase.gsub(/[^a-z0-9]/,'-').squeeze('-').gsub(/^\-|\-$/,'') self['slug'] = title.downcase.gsub(/[^a-z0-9]/,'-').squeeze('-').gsub(/^\-|\-$/,'')
end end
end end
@ -61,6 +60,7 @@ describe CouchRest::Model do
describe "a new model" do describe "a new model" do
it "should be a new_record" do it "should be a new_record" do
@obj = Basic.new @obj = Basic.new
@obj.rev.should be_nil
@obj.should be_a_new_record @obj.should be_a_new_record
end end
end end
@ -68,13 +68,13 @@ describe CouchRest::Model do
describe "a model with key_accessors" do describe "a model with key_accessors" do
it "should allow reading keys" do it "should allow reading keys" do
@art = Article.new @art = Article.new
@art.doc['title'] = 'My Article Title' @art['title'] = 'My Article Title'
@art.title.should == 'My Article Title' @art.title.should == 'My Article Title'
end end
it "should allow setting keys" do it "should allow setting keys" do
@art = Article.new @art = Article.new
@art.title = 'My Article Title' @art.title = 'My Article Title'
@art.doc['title'].should == 'My Article Title' @art['title'].should == 'My Article Title'
end end
end end
@ -83,7 +83,7 @@ describe CouchRest::Model do
@art = Article.new @art = Article.new
t = Time.now t = Time.now
@art.date = t @art.date = t
@art.doc['date'].should == t @art['date'].should == t
end end
it "should not allow reading keys" do it "should not allow reading keys" do
@art = Article.new @art = Article.new
@ -96,7 +96,7 @@ describe CouchRest::Model do
describe "a model with key_readers" do describe "a model with key_readers" do
it "should allow reading keys" do it "should allow reading keys" do
@art = Article.new @art = Article.new
@art.doc['slug'] = 'my-slug' @art['slug'] = 'my-slug'
@art.slug.should == 'my-slug' @art.slug.should == 'my-slug'
end end
it "should not allow setting keys" do it "should not allow setting keys" do
@ -129,7 +129,7 @@ describe CouchRest::Model do
it "should be set for resaving" do it "should be set for resaving" do
rev = @obj.rev rev = @obj.rev
@obj.doc['another-key'] = "some value" @obj['another-key'] = "some value"
@obj.save @obj.save
@obj.rev.should_not == rev @obj.rev.should_not == rev
end end
@ -139,7 +139,7 @@ describe CouchRest::Model do
end end
it "should set the type" do it "should set the type" do
@obj.doc['type'].should == 'Basic' @obj['type'].should == 'Basic'
end end
end end
@ -254,7 +254,7 @@ describe CouchRest::Model do
end end
it "should sort correctly" do it "should sort correctly" do
articles = Article.by_user_id_and_date articles = Article.by_user_id_and_date
articles.collect{|a|a.doc['user_id']}.should == ['aaron', 'aaron', 'quentin', 'quentin'] articles.collect{|a|a['user_id']}.should == ['aaron', 'aaron', 'quentin', 'quentin']
articles[1].title.should == 'not junk' articles[1].title.should == 'not junk'
end end
it "should be queryable with couchrest options" do it "should be queryable with couchrest options" do