require 'active_resource/connection'
require 'cgi'
require 'set'
module ActiveResource
# ActiveResource::Base is the main class for mapping RESTful resources as models in a Rails application.
#
# For an outline of what Active Resource is capable of, see link:files/vendor/rails/activeresource/README.html.
#
# == Automated mapping
#
# Active Resource objects represent your RESTful resources as manipulatable Ruby objects. To map resources
# to Ruby objects, Active Resource only needs a class name that corresponds to the resource name (e.g., the class
# Person maps to the resources people, very similarly to Active Record) and a +site+ value, which holds the
# URI of the resources.
#
# class Person < ActiveResource::Base
# self.site = "http://api.people.com:3000/"
# end
#
# Now the Person class is mapped to RESTful resources located at http://api.people.com:3000/people/, and
# you can now use Active Resource's lifecycle methods to manipulate resources. In the case where you already have
# an existing model with the same name as the desired RESTful resource you can set the +element_name+ value.
#
# class PersonResource < ActiveResource::Base
# self.site = "http://api.people.com:3000/"
# self.element_name = "person"
# end
#
#
# == Lifecycle methods
#
# Active Resource exposes methods for creating, finding, updating, and deleting resources
# from REST web services.
#
# ryan = Person.new(:first => 'Ryan', :last => 'Daigle')
# ryan.save # => true
# ryan.id # => 2
# Person.exists?(ryan.id) # => true
# ryan.exists? # => true
#
# ryan = Person.find(1)
# # Resource holding our newly created Person object
#
# ryan.first = 'Rizzle'
# ryan.save # => true
#
# ryan.destroy # => true
#
# As you can see, these are very similar to Active Record's lifecycle methods for database records.
# You can read more about each of these methods in their respective documentation.
#
# === Custom REST methods
#
# Since simple CRUD/lifecycle methods can't accomplish every task, Active Resource also supports
# defining your own custom REST methods. To invoke them, Active Resource provides the get,
# post, put and \delete methods where you can specify a custom REST method
# name to invoke.
#
# # POST to the custom 'register' REST method, i.e. POST /people/new/register.xml.
# Person.new(:name => 'Ryan').post(:register)
# # => { :id => 1, :name => 'Ryan', :position => 'Clerk' }
#
# # PUT an update by invoking the 'promote' REST method, i.e. PUT /people/1/promote.xml?position=Manager.
# Person.find(1).put(:promote, :position => 'Manager')
# # => { :id => 1, :name => 'Ryan', :position => 'Manager' }
#
# # GET all the positions available, i.e. GET /people/positions.xml.
# Person.get(:positions)
# # => [{:name => 'Manager'}, {:name => 'Clerk'}]
#
# # DELETE to 'fire' a person, i.e. DELETE /people/1/fire.xml.
# Person.find(1).delete(:fire)
#
# For more information on using custom REST methods, see the
# ActiveResource::CustomMethods documentation.
#
# == Validations
#
# You can validate resources client side by overriding validation methods in the base class.
#
# class Person < ActiveResource::Base
# self.site = "http://api.people.com:3000/"
# protected
# def validate
# errors.add("last", "has invalid characters") unless last =~ /[a-zA-Z]*/
# end
# end
#
# See the ActiveResource::Validations documentation for more information.
#
# == Authentication
#
# Many REST APIs will require authentication, usually in the form of basic
# HTTP authentication. Authentication can be specified by:
# * putting the credentials in the URL for the +site+ variable.
#
# class Person < ActiveResource::Base
# self.site = "http://ryan:password@api.people.com:3000/"
# end
#
# * defining +user+ and/or +password+ variables
#
# class Person < ActiveResource::Base
# self.site = "http://api.people.com:3000/"
# self.user = "ryan"
# self.password = "password"
# end
#
# For obvious security reasons, it is probably best if such services are available
# over HTTPS.
#
# Note: Some values cannot be provided in the URL passed to site. e.g. email addresses
# as usernames. In those situations you should use the separate user and password option.
#
# == Errors & Validation
#
# Error handling and validation is handled in much the same manner as you're used to seeing in
# Active Record. Both the response code in the HTTP response and the body of the response are used to
# indicate that an error occurred.
#
# === Resource errors
#
# When a GET is requested for a resource that does not exist, the HTTP 404 (Resource Not Found)
# response code will be returned from the server which will raise an ActiveResource::ResourceNotFound
# exception.
#
# # GET http://api.people.com:3000/people/999.xml
# ryan = Person.find(999) # 404, raises ActiveResource::ResourceNotFound
#
# 404 is just one of the HTTP error response codes that Active Resource will handle with its own exception. The
# following HTTP response codes will also result in these exceptions:
#
# * 200..399 - Valid response, no exception (other than 301, 302)
# * 301, 302 - ActiveResource::Redirection
# * 400 - ActiveResource::BadRequest
# * 401 - ActiveResource::UnauthorizedAccess
# * 403 - ActiveResource::ForbiddenAccess
# * 404 - ActiveResource::ResourceNotFound
# * 405 - ActiveResource::MethodNotAllowed
# * 409 - ActiveResource::ResourceConflict
# * 422 - ActiveResource::ResourceInvalid (rescued by save as validation errors)
# * 401..499 - ActiveResource::ClientError
# * 500..599 - ActiveResource::ServerError
# * Other - ActiveResource::ConnectionError
#
# These custom exceptions allow you to deal with resource errors more naturally and with more precision
# rather than returning a general HTTP error. For example:
#
# begin
# ryan = Person.find(my_id)
# rescue ActiveResource::ResourceNotFound
# redirect_to :action => 'not_found'
# rescue ActiveResource::ResourceConflict, ActiveResource::ResourceInvalid
# redirect_to :action => 'new'
# end
#
# === Validation errors
#
# Active Resource supports validations on resources and will return errors if any of these validations fail
# (e.g., "First name can not be blank" and so on). These types of errors are denoted in the response by
# a response code of 422 and an XML representation of the validation errors. The save operation will
# then fail (with a false return value) and the validation errors can be accessed on the resource in question.
#
# ryan = Person.find(1)
# ryan.first # => ''
# ryan.save # => false
#
# # When
# # PUT http://api.people.com:3000/people/1.xml
# # is requested with invalid values, the response is:
# #
# # Response (422):
# # First cannot be empty
# #
#
# ryan.errors.invalid?(:first) # => true
# ryan.errors.full_messages # => ['First cannot be empty']
#
# Learn more about Active Resource's validation features in the ActiveResource::Validations documentation.
#
# === Timeouts
#
# Active Resource relies on HTTP to access RESTful APIs and as such is inherently susceptible to slow or
# unresponsive servers. In such cases, your Active Resource method calls could \timeout. You can control the
# amount of time before Active Resource times out with the +timeout+ variable.
#
# class Person < ActiveResource::Base
# self.site = "http://api.people.com:3000/"
# self.timeout = 5
# end
#
# This sets the +timeout+ to 5 seconds. You can adjust the +timeout+ to a value suitable for the RESTful API
# you are accessing. It is recommended to set this to a reasonably low value to allow your Active Resource
# clients (especially if you are using Active Resource in a Rails application) to fail-fast (see
# http://en.wikipedia.org/wiki/Fail-fast) rather than cause cascading failures that could incapacitate your
# server.
#
# When a \timeout occurs, an ActiveResource::TimeoutError is raised. You should rescue from
# ActiveResource::TimeoutError in your Active Resource method calls.
#
# Internally, Active Resource relies on Ruby's Net::HTTP library to make HTTP requests. Setting +timeout+
# sets the read_timeout of the internal Net::HTTP instance to the same value. The default
# read_timeout is 60 seconds on most Ruby implementations.
class Base
##
# :singleton-method:
# The logger for diagnosing and tracing Active Resource calls.
cattr_accessor :logger
class << self
# Gets the URI of the REST resources to map for this class. The site variable is required for
# Active Resource's mapping to work.
def site
# Not using superclass_delegating_reader because don't want subclasses to modify superclass instance
#
# With superclass_delegating_reader
#
# Parent.site = 'http://anonymous@test.com'
# Subclass.site # => 'http://anonymous@test.com'
# Subclass.site.user = 'david'
# Parent.site # => 'http://david@test.com'
#
# Without superclass_delegating_reader (expected behaviour)
#
# Parent.site = 'http://anonymous@test.com'
# Subclass.site # => 'http://anonymous@test.com'
# Subclass.site.user = 'david' # => TypeError: can't modify frozen object
#
if defined?(@site)
@site
elsif superclass != Object && superclass.site
superclass.site.dup.freeze
end
end
# Sets the URI of the REST resources to map for this class to the value in the +site+ argument.
# The site variable is required for Active Resource's mapping to work.
def site=(site)
@connection = nil
if site.nil?
@site = nil
else
@site = create_site_uri_from(site)
@user = URI.decode(@site.user) if @site.user
@password = URI.decode(@site.password) if @site.password
end
end
# Gets the \user for REST HTTP authentication.
def user
# Not using superclass_delegating_reader. See +site+ for explanation
if defined?(@user)
@user
elsif superclass != Object && superclass.user
superclass.user.dup.freeze
end
end
# Sets the \user for REST HTTP authentication.
def user=(user)
@connection = nil
@user = user
end
# Gets the \password for REST HTTP authentication.
def password
# Not using superclass_delegating_reader. See +site+ for explanation
if defined?(@password)
@password
elsif superclass != Object && superclass.password
superclass.password.dup.freeze
end
end
# Sets the \password for REST HTTP authentication.
def password=(password)
@connection = nil
@password = password
end
# Sets the format that attributes are sent and received in from a mime type reference:
#
# Person.format = :json
# Person.find(1) # => GET /people/1.json
#
# Person.format = ActiveResource::Formats::XmlFormat
# Person.find(1) # => GET /people/1.xml
#
# Default format is :xml.
def format=(mime_type_reference_or_format)
format = mime_type_reference_or_format.is_a?(Symbol) ?
ActiveResource::Formats[mime_type_reference_or_format] : mime_type_reference_or_format
write_inheritable_attribute(:format, format)
connection.format = format if site
end
# Returns the current format, default is ActiveResource::Formats::XmlFormat.
def format
read_inheritable_attribute(:format) || ActiveResource::Formats[:xml]
end
# Sets the number of seconds after which requests to the REST API should time out.
def timeout=(timeout)
@connection = nil
@timeout = timeout
end
# Gets the number of seconds after which requests to the REST API should time out.
def timeout
if defined?(@timeout)
@timeout
elsif superclass != Object && superclass.timeout
superclass.timeout
end
end
# An instance of ActiveResource::Connection that is the base \connection to the remote service.
# The +refresh+ parameter toggles whether or not the \connection is refreshed at every request
# or not (defaults to false).
def connection(refresh = false)
if defined?(@connection) || superclass == Object
@connection = Connection.new(site, format) if refresh || @connection.nil?
@connection.user = user if user
@connection.password = password if password
@connection.timeout = timeout if timeout
@connection
else
superclass.connection
end
end
def headers
@headers ||= {}
end
# Do not include any modules in the default element name. This makes it easier to seclude ARes objects
# in a separate namespace without having to set element_name repeatedly.
attr_accessor_with_default(:element_name) { to_s.split("::").last.underscore } #:nodoc:
attr_accessor_with_default(:collection_name) { element_name.pluralize } #:nodoc:
attr_accessor_with_default(:primary_key, 'id') #:nodoc:
# Gets the \prefix for a resource's nested URL (e.g., prefix/collectionname/1.xml)
# This method is regenerated at runtime based on what the \prefix is set to.
def prefix(options={})
default = site.path
default << '/' unless default[-1..-1] == '/'
# generate the actual method based on the current site path
self.prefix = default
prefix(options)
end
# An attribute reader for the source string for the resource path \prefix. This
# method is regenerated at runtime based on what the \prefix is set to.
def prefix_source
prefix # generate #prefix and #prefix_source methods first
prefix_source
end
# Sets the \prefix for a resource's nested URL (e.g., prefix/collectionname/1.xml).
# Default value is site.path.
def prefix=(value = '/')
# Replace :placeholders with '#{embedded options[:lookups]}'
prefix_call = value.gsub(/:\w+/) { |key| "\#{options[#{key}]}" }
# Clear prefix parameters in case they have been cached
@prefix_parameters = nil
# Redefine the new methods.
code = <<-end_code
def prefix_source() "#{value}" end
def prefix(options={}) "#{prefix_call}" end
end_code
silence_warnings { instance_eval code, __FILE__, __LINE__ }
rescue
logger.error "Couldn't set prefix: #{$!}\n #{code}"
raise
end
alias_method :set_prefix, :prefix= #:nodoc:
alias_method :set_element_name, :element_name= #:nodoc:
alias_method :set_collection_name, :collection_name= #:nodoc:
# Gets the element path for the given ID in +id+. If the +query_options+ parameter is omitted, Rails
# will split from the \prefix options.
#
# ==== Options
# +prefix_options+ - A \hash to add a \prefix to the request for nested URLs (e.g., :account_id => 19
# would yield a URL like /accounts/19/purchases.xml).
# +query_options+ - A \hash to add items to the query string for the request.
#
# ==== Examples
# Post.element_path(1)
# # => /posts/1.xml
#
# Comment.element_path(1, :post_id => 5)
# # => /posts/5/comments/1.xml
#
# Comment.element_path(1, :post_id => 5, :active => 1)
# # => /posts/5/comments/1.xml?active=1
#
# Comment.element_path(1, {:post_id => 5}, {:active => 1})
# # => /posts/5/comments/1.xml?active=1
#
def element_path(id, prefix_options = {}, query_options = nil)
prefix_options, query_options = split_options(prefix_options) if query_options.nil?
"#{prefix(prefix_options)}#{collection_name}/#{id}.#{format.extension}#{query_string(query_options)}"
end
# Gets the collection path for the REST resources. If the +query_options+ parameter is omitted, Rails
# will split from the +prefix_options+.
#
# ==== Options
# * +prefix_options+ - A hash to add a prefix to the request for nested URLs (e.g., :account_id => 19
# would yield a URL like /accounts/19/purchases.xml).
# * +query_options+ - A hash to add items to the query string for the request.
#
# ==== Examples
# Post.collection_path
# # => /posts.xml
#
# Comment.collection_path(:post_id => 5)
# # => /posts/5/comments.xml
#
# Comment.collection_path(:post_id => 5, :active => 1)
# # => /posts/5/comments.xml?active=1
#
# Comment.collection_path({:post_id => 5}, {:active => 1})
# # => /posts/5/comments.xml?active=1
#
def collection_path(prefix_options = {}, query_options = nil)
prefix_options, query_options = split_options(prefix_options) if query_options.nil?
"#{prefix(prefix_options)}#{collection_name}.#{format.extension}#{query_string(query_options)}"
end
alias_method :set_primary_key, :primary_key= #:nodoc:
# Creates a new resource instance and makes a request to the remote service
# that it be saved, making it equivalent to the following simultaneous calls:
#
# ryan = Person.new(:first => 'ryan')
# ryan.save
#
# Returns the newly created resource. If a failure has occurred an
# exception will be raised (see save). If the resource is invalid and
# has not been saved then valid? will return false,
# while new? will still return true.
#
# ==== Examples
# Person.create(:name => 'Jeremy', :email => 'myname@nospam.com', :enabled => true)
# my_person = Person.find(:first)
# my_person.email # => myname@nospam.com
#
# dhh = Person.create(:name => 'David', :email => 'dhh@nospam.com', :enabled => true)
# dhh.valid? # => true
# dhh.new? # => false
#
# # We'll assume that there's a validation that requires the name attribute
# that_guy = Person.create(:name => '', :email => 'thatguy@nospam.com', :enabled => true)
# that_guy.valid? # => false
# that_guy.new? # => true
def create(attributes = {})
self.new(attributes).tap { |resource| resource.save }
end
# Core method for finding resources. Used similarly to Active Record's +find+ method.
#
# ==== Arguments
# The first argument is considered to be the scope of the query. That is, how many
# resources are returned from the request. It can be one of the following.
#
# * :one - Returns a single resource.
# * :first - Returns the first resource found.
# * :last - Returns the last resource found.
# * :all - Returns every resource that matches the request.
#
# ==== Options
#
# * :from - Sets the path or custom method that resources will be fetched from.
# * :params - Sets query and \prefix (nested URL) parameters.
#
# ==== Examples
# Person.find(1)
# # => GET /people/1.xml
#
# Person.find(:all)
# # => GET /people.xml
#
# Person.find(:all, :params => { :title => "CEO" })
# # => GET /people.xml?title=CEO
#
# Person.find(:first, :from => :managers)
# # => GET /people/managers.xml
#
# Person.find(:last, :from => :managers)
# # => GET /people/managers.xml
#
# Person.find(:all, :from => "/companies/1/people.xml")
# # => GET /companies/1/people.xml
#
# Person.find(:one, :from => :leader)
# # => GET /people/leader.xml
#
# Person.find(:all, :from => :developers, :params => { :language => 'ruby' })
# # => GET /people/developers.xml?language=ruby
#
# Person.find(:one, :from => "/companies/1/manager.xml")
# # => GET /companies/1/manager.xml
#
# StreetAddress.find(1, :params => { :person_id => 1 })
# # => GET /people/1/street_addresses/1.xml
def find(*arguments)
scope = arguments.slice!(0)
options = arguments.slice!(0) || {}
case scope
when :all then find_every(options)
when :first then find_every(options).first
when :last then find_every(options).last
when :one then find_one(options)
else find_single(scope, options)
end
end
# Deletes the resources with the ID in the +id+ parameter.
#
# ==== Options
# All options specify \prefix and query parameters.
#
# ==== Examples
# Event.delete(2) # sends DELETE /events/2
#
# Event.create(:name => 'Free Concert', :location => 'Community Center')
# my_event = Event.find(:first) # let's assume this is event with ID 7
# Event.delete(my_event.id) # sends DELETE /events/7
#
# # Let's assume a request to events/5/cancel.xml
# Event.delete(params[:id]) # sends DELETE /events/5
def delete(id, options = {})
connection.delete(element_path(id, options))
end
# Asserts the existence of a resource, returning true if the resource is found.
#
# ==== Examples
# Note.create(:title => 'Hello, world.', :body => 'Nothing more for now...')
# Note.exists?(1) # => true
#
# Note.exists(1349) # => false
def exists?(id, options = {})
if id
prefix_options, query_options = split_options(options[:params])
path = element_path(id, prefix_options, query_options)
response = connection.head(path, headers)
response.code.to_i == 200
end
# id && !find_single(id, options).nil?
rescue ActiveResource::ResourceNotFound
false
end
private
# Find every resource
def find_every(options)
case from = options[:from]
when Symbol
instantiate_collection(get(from, options[:params]))
when String
path = "#{from}#{query_string(options[:params])}"
instantiate_collection(connection.get(path, headers) || [])
else
prefix_options, query_options = split_options(options[:params])
path = collection_path(prefix_options, query_options)
instantiate_collection( (connection.get(path, headers) || []), prefix_options )
end
end
# Find a single resource from a one-off URL
def find_one(options)
case from = options[:from]
when Symbol
instantiate_record(get(from, options[:params]))
when String
path = "#{from}#{query_string(options[:params])}"
instantiate_record(connection.get(path, headers))
end
end
# Find a single resource from the default URL
def find_single(scope, options)
prefix_options, query_options = split_options(options[:params])
path = element_path(scope, prefix_options, query_options)
instantiate_record(connection.get(path, headers), prefix_options)
end
def instantiate_collection(collection, prefix_options = {})
collection.collect! { |record| instantiate_record(record, prefix_options) }
end
def instantiate_record(record, prefix_options = {})
new(record).tap do |resource|
resource.prefix_options = prefix_options
end
end
# Accepts a URI and creates the site URI from that.
def create_site_uri_from(site)
site.is_a?(URI) ? site.dup : URI.parse(site)
end
# contains a set of the current prefix parameters.
def prefix_parameters
@prefix_parameters ||= prefix_source.scan(/:\w+/).map { |key| key[1..-1].to_sym }.to_set
end
# Builds the query string for the request.
def query_string(options)
"?#{options.to_query}" unless options.nil? || options.empty?
end
# split an option hash into two hashes, one containing the prefix options,
# and the other containing the leftovers.
def split_options(options = {})
prefix_options, query_options = {}, {}
(options || {}).each do |key, value|
next if key.blank?
(prefix_parameters.include?(key.to_sym) ? prefix_options : query_options)[key.to_sym] = value
end
[ prefix_options, query_options ]
end
end
attr_accessor :attributes #:nodoc:
attr_accessor :prefix_options #:nodoc:
# Constructor method for \new resources; the optional +attributes+ parameter takes a \hash
# of attributes for the \new resource.
#
# ==== Examples
# my_course = Course.new
# my_course.name = "Western Civilization"
# my_course.lecturer = "Don Trotter"
# my_course.save
#
# my_other_course = Course.new(:name => "Philosophy: Reason and Being", :lecturer => "Ralph Cling")
# my_other_course.save
def initialize(attributes = {})
@attributes = {}
@prefix_options = {}
load(attributes)
end
# Returns a \clone of the resource that hasn't been assigned an +id+ yet and
# is treated as a \new resource.
#
# ryan = Person.find(1)
# not_ryan = ryan.clone
# not_ryan.new? # => true
#
# Any active resource member attributes will NOT be cloned, though all other
# attributes are. This is to prevent the conflict between any +prefix_options+
# that refer to the original parent resource and the newly cloned parent
# resource that does not exist.
#
# ryan = Person.find(1)
# ryan.address = StreetAddress.find(1, :person_id => ryan.id)
# ryan.hash = {:not => "an ARes instance"}
#
# not_ryan = ryan.clone
# not_ryan.new? # => true
# not_ryan.address # => NoMethodError
# not_ryan.hash # => {:not => "an ARes instance"}
def clone
# Clone all attributes except the pk and any nested ARes
cloned = attributes.reject {|k,v| k == self.class.primary_key || v.is_a?(ActiveResource::Base)}.inject({}) do |attrs, (k, v)|
attrs[k] = v.clone
attrs
end
# Form the new resource - bypass initialize of resource with 'new' as that will call 'load' which
# attempts to convert hashes into member objects and arrays into collections of objects. We want
# the raw objects to be cloned so we bypass load by directly setting the attributes hash.
resource = self.class.new({})
resource.prefix_options = self.prefix_options
resource.send :instance_variable_set, '@attributes', cloned
resource
end
# Returns +true+ if this object hasn't yet been saved, otherwise, returns +false+.
#
# ==== Examples
# not_new = Computer.create(:brand => 'Apple', :make => 'MacBook', :vendor => 'MacMall')
# not_new.new? # => false
#
# is_new = Computer.new(:brand => 'IBM', :make => 'Thinkpad', :vendor => 'IBM')
# is_new.new? # => true
#
# is_new.save
# is_new.new? # => false
#
def new?
id.nil?
end
alias :new_record? :new?
# Gets the \id attribute of the resource.
def id
attributes[self.class.primary_key]
end
# Sets the \id attribute of the resource.
def id=(id)
attributes[self.class.primary_key] = id
end
# Allows Active Resource objects to be used as parameters in Action Pack URL generation.
def to_param
id && id.to_s
end
# Test for equality. Resource are equal if and only if +other+ is the same object or
# is an instance of the same class, is not new?, and has the same +id+.
#
# ==== Examples
# ryan = Person.create(:name => 'Ryan')
# jamie = Person.create(:name => 'Jamie')
#
# ryan == jamie
# # => false (Different name attribute and id)
#
# ryan_again = Person.new(:name => 'Ryan')
# ryan == ryan_again
# # => false (ryan_again is new?)
#
# ryans_clone = Person.create(:name => 'Ryan')
# ryan == ryans_clone
# # => false (Different id attributes)
#
# ryans_twin = Person.find(ryan.id)
# ryan == ryans_twin
# # => true
#
def ==(other)
other.equal?(self) || (other.instance_of?(self.class) && other.id == id && other.prefix_options == prefix_options)
end
# Tests for equality (delegates to ==).
def eql?(other)
self == other
end
# Delegates to id in order to allow two resources of the same type and \id to work with something like:
# [Person.find(1), Person.find(2)] & [Person.find(1), Person.find(4)] # => [Person.find(1)]
def hash
id.hash
end
# Duplicates the current resource without saving it.
#
# ==== Examples
# my_invoice = Invoice.create(:customer => 'That Company')
# next_invoice = my_invoice.dup
# next_invoice.new? # => true
#
# next_invoice.save
# next_invoice == my_invoice # => false (different id attributes)
#
# my_invoice.customer # => That Company
# next_invoice.customer # => That Company
def dup
self.class.new.tap do |resource|
resource.attributes = @attributes
resource.prefix_options = @prefix_options
end
end
# Saves (+POST+) or \updates (+PUT+) a resource. Delegates to +create+ if the object is \new,
# +update+ if it exists. If the response to the \save includes a body, it will be assumed that this body
# is XML for the final object as it looked after the \save (which would include attributes like +created_at+
# that weren't part of the original submit).
#
# ==== Examples
# my_company = Company.new(:name => 'RoleModel Software', :owner => 'Ken Auer', :size => 2)
# my_company.new? # => true
# my_company.save # sends POST /companies/ (create)
#
# my_company.new? # => false
# my_company.size = 10
# my_company.save # sends PUT /companies/1 (update)
def save
new? ? create : update
end
# Deletes the resource from the remote service.
#
# ==== Examples
# my_id = 3
# my_person = Person.find(my_id)
# my_person.destroy
# Person.find(my_id) # 404 (Resource Not Found)
#
# new_person = Person.create(:name => 'James')
# new_id = new_person.id # => 7
# new_person.destroy
# Person.find(new_id) # 404 (Resource Not Found)
def destroy
connection.delete(element_path, self.class.headers)
end
# Evaluates to true if this resource is not new? and is
# found on the remote service. Using this method, you can check for
# resources that may have been deleted between the object's instantiation
# and actions on it.
#
# ==== Examples
# Person.create(:name => 'Theodore Roosevelt')
# that_guy = Person.find(:first)
# that_guy.exists? # => true
#
# that_lady = Person.new(:name => 'Paul Bean')
# that_lady.exists? # => false
#
# guys_id = that_guy.id
# Person.delete(guys_id)
# that_guy.exists? # => false
def exists?
!new? && self.class.exists?(to_param, :params => prefix_options)
end
# Converts the resource to an XML string representation.
#
# ==== Options
# The +options+ parameter is handed off to the +to_xml+ method on each
# attribute, so it has the same options as the +to_xml+ methods in
# Active Support.
#
# * :indent - Set the indent level for the XML output (default is +2+).
# * :dasherize - Boolean option to determine whether or not element names should
# replace underscores with dashes (default is false).
# * :skip_instruct - Toggle skipping the +instruct!+ call on the XML builder
# that generates the XML declaration (default is false).
#
# ==== Examples
# my_group = SubsidiaryGroup.find(:first)
# my_group.to_xml
# # =>
# # [...]
#
# my_group.to_xml(:dasherize => true)
# # =>
# # [...]
#
# my_group.to_xml(:skip_instruct => true)
# # => [...]
def to_xml(options={})
attributes.to_xml({:root => self.class.element_name}.merge(options))
end
# Converts the resource to a JSON string representation.
#
# ==== Options
# The +options+ are passed to the +to_json+ method on each
# attribute, so the same options as the +to_json+ methods in
# Active Support.
#
# * :only - Only include the specified attribute or list of
# attributes in the serialized output. Attribute names must be specified
# as strings.
# * :except - Do not include the specified attribute or list of
# attributes in the serialized output. Attribute names must be specified
# as strings.
#
# ==== Examples
# person = Person.new(:first_name => "Jim", :last_name => "Smith")
# person.to_json
# # => {"first_name": "Jim", "last_name": "Smith"}
#
# person.to_json(:only => ["first_name"])
# # => {"first_name": "Jim"}
#
# person.to_json(:except => ["first_name"])
# # => {"last_name": "Smith"}
def to_json(options={})
ActiveSupport::JSON.encode(attributes, options)
end
# Returns the serialized string representation of the resource in the configured
# serialization format specified in ActiveResource::Base.format. The options
# applicable depend on the configured encoding format.
def encode(options={})
case self.class.format
when ActiveResource::Formats[:xml]
self.class.format.encode(attributes, {:root => self.class.element_name}.merge(options))
else
self.class.format.encode(attributes, options)
end
end
# A method to \reload the attributes of this object from the remote web service.
#
# ==== Examples
# my_branch = Branch.find(:first)
# my_branch.name # => "Wislon Raod"
#
# # Another client fixes the typo...
#
# my_branch.name # => "Wislon Raod"
# my_branch.reload
# my_branch.name # => "Wilson Road"
def reload
self.load(self.class.find(to_param, :params => @prefix_options).attributes)
end
# A method to manually load attributes from a \hash. Recursively loads collections of
# resources. This method is called in +initialize+ and +create+ when a \hash of attributes
# is provided.
#
# ==== Examples
# my_attrs = {:name => 'J&J Textiles', :industry => 'Cloth and textiles'}
# my_attrs = {:name => 'Marty', :colors => ["red", "green", "blue"]}
#
# the_supplier = Supplier.find(:first)
# the_supplier.name # => 'J&M Textiles'
# the_supplier.load(my_attrs)
# the_supplier.name('J&J Textiles')
#
# # These two calls are the same as Supplier.new(my_attrs)
# my_supplier = Supplier.new
# my_supplier.load(my_attrs)
#
# # These three calls are the same as Supplier.create(my_attrs)
# your_supplier = Supplier.new
# your_supplier.load(my_attrs)
# your_supplier.save
def load(attributes)
raise ArgumentError, "expected an attributes Hash, got #{attributes.inspect}" unless attributes.is_a?(Hash)
@prefix_options, attributes = split_options(attributes)
attributes.each do |key, value|
@attributes[key.to_s] =
case value
when Array
resource = find_or_create_resource_for_collection(key)
value.map { |attrs| attrs.is_a?(String) ? attrs.dup : resource.new(attrs) }
when Hash
resource = find_or_create_resource_for(key)
resource.new(value)
else
value.dup rescue value
end
end
self
end
# For checking respond_to? without searching the attributes (which is faster).
alias_method :respond_to_without_attributes?, :respond_to?
# A method to determine if an object responds to a message (e.g., a method call). In Active Resource, a Person object with a
# +name+ attribute can answer true to my_person.respond_to?(:name), my_person.respond_to?(:name=), and
# my_person.respond_to?(:name?).
def respond_to?(method, include_priv = false)
method_name = method.to_s
if attributes.nil?
return super
elsif attributes.has_key?(method_name)
return true
elsif ['?','='].include?(method_name.last) && attributes.has_key?(method_name.first(-1))
return true
end
# super must be called at the end of the method, because the inherited respond_to?
# would return true for generated readers, even if the attribute wasn't present
super
end
protected
def connection(refresh = false)
self.class.connection(refresh)
end
# Update the resource on the remote service.
def update
connection.put(element_path(prefix_options), encode, self.class.headers).tap do |response|
load_attributes_from_response(response)
end
end
# Create (i.e., \save to the remote service) the \new resource.
def create
connection.post(collection_path, encode, self.class.headers).tap do |response|
self.id = id_from_response(response)
load_attributes_from_response(response)
end
end
def load_attributes_from_response(response)
if response['Content-Length'] != "0" && response.body.strip.size > 0
load(self.class.format.decode(response.body))
end
end
# Takes a response from a typical create post and pulls the ID out
def id_from_response(response)
response['Location'][/\/([^\/]*?)(\.\w+)?$/, 1] if response['Location']
end
def element_path(options = nil)
self.class.element_path(to_param, options || prefix_options)
end
def collection_path(options = nil)
self.class.collection_path(options || prefix_options)
end
private
# Tries to find a resource for a given collection name; if it fails, then the resource is created
def find_or_create_resource_for_collection(name)
find_or_create_resource_for(name.to_s.singularize)
end
# Tries to find a resource in a non empty list of nested modules
# Raises a NameError if it was not found in any of the given nested modules
def find_resource_in_modules(resource_name, module_names)
receiver = Object
namespaces = module_names[0, module_names.size-1].map do |module_name|
receiver = receiver.const_get(module_name)
end
if namespace = namespaces.reverse.detect { |ns| ns.const_defined?(resource_name) }
return namespace.const_get(resource_name)
else
raise NameError
end
end
# Tries to find a resource for a given name; if it fails, then the resource is created
def find_or_create_resource_for(name)
resource_name = name.to_s.camelize
ancestors = self.class.name.split("::")
if ancestors.size > 1
find_resource_in_modules(resource_name, ancestors)
else
self.class.const_get(resource_name)
end
rescue NameError
if self.class.const_defined?(resource_name)
resource = self.class.const_get(resource_name)
else
resource = self.class.const_set(resource_name, Class.new(ActiveResource::Base))
end
resource.prefix = self.class.prefix
resource.site = self.class.site
resource
end
def split_options(options = {})
self.class.__send__(:split_options, options)
end
# For compatibility with ActiveSupport::JSON.encode
def rails_to_json(options, *args)
to_json(options)
end
def method_missing(method_symbol, *arguments) #:nodoc:
method_name = method_symbol.to_s
case method_name.last
when "="
attributes[method_name.first(-1)] = arguments.first
when "?"
attributes[method_name.first(-1)]
else
attributes.has_key?(method_name) ? attributes[method_name] : super
end
end
end
end