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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 <tt>http://api.people.com:3000/people/</tt>, and
# you can now use Active Resource's lifecycles 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 <tt>get</tt>,
# <tt>post</tt>, <tt>put</tt> and <tt>delete</tt> 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 <tt>404</tt> (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
#
# <tt>404</tt> 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
# * 404 - ActiveResource::ResourceNotFound
# * 409 - ActiveResource::ResourceConflict
# * 422 - ActiveResource::ResourceInvalid (rescued by save as validation errors)
# * 401..499 - ActiveResource::ClientError
# * 500..599 - ActiveResource::ServerError
#
# 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 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 <tt>422</tt> and an XML representation of the validation errors. The save operation will
# then fail (with a <tt>false</tt> 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):
# # <errors type="array"><error>First cannot be empty</error></errors>
# #
#
# 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 <tt>read_timeout</tt> of the internal Net::HTTP instance to the same value. The default
# <tt>read_timeout</tt> is 60 seconds on most Ruby implementations.
class Base
# 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 <tt>:xml</tt>.
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 <tt>false</tt>).
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., <tt>prefix/collectionname/1.xml</tt>)
# 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., <tt>prefix/collectionname/1.xml</tt>).
# Default value is <tt>site.path</tt>.
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., <tt>:account_id => 19</tt>
# would yield a URL like <tt>/accounts/19/purchases.xml</tt>).
# +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 URL's (e.g., <tt>:account_id => 19</tt>
# would yield a URL like <tt>/accounts/19/purchases.xml</tt>).
# * +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 <tt>save</tt>). If the resource is invalid and
# has not been saved then <tt>valid?</tt> will return <tt>false</tt>,
# while <tt>new?</tt> will still return <tt>true</tt>.
#
# ==== 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 = {})
returning(self.new(attributes)) { |res| res.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.
#
# * <tt>:one</tt> - Returns a single resource.
# * <tt>:first</tt> - Returns the first resource found.
# * <tt>:last</tt> - Returns the last resource found.
# * <tt>:all</tt> - Returns every resource that matches the request.
#
# ==== Options
#
# * <tt>:from</tt> - Sets the path or custom method that resources will be fetched from.
# * <tt>:params</tt> - 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 <tt>true</tt> 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 = {})
returning new(record) 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
# A method to determine if the resource a new object (i.e., it has not been POSTed to the remote service yet).
#
# ==== 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
# Get the +id+ attribute of the resource.
def id
attributes[self.class.primary_key]
end
# Set 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 <tt>new?</tt>, 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.new? && other.id == id)
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
# Duplicate 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
returning self.class.new do |resource|
resource.attributes = @attributes
resource.prefix_options = @prefix_options
end
end
# A method to save (+POST+) or update (+PUT+) a resource. It delegates to +create+ if a new object,
# +update+ if it is existing. 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 <tt>true</tt> if this resource is not <tt>new?</tt> 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
# A method to convert the the resource to an XML string.
#
# ==== 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.
#
# * <tt>:indent</tt> - Set the indent level for the XML output (default is +2+).
# * <tt>:dasherize</tt> - Boolean option to determine whether or not element names should
# replace underscores with dashes (default is <tt>false</tt>).
# * <tt>:skip_instruct</tt> - Toggle skipping the +instruct!+ call on the XML builder
# that generates the XML declaration (default is <tt>false</tt>).
#
# ==== Examples
# my_group = SubsidiaryGroup.find(:first)
# my_group.to_xml
# # => <?xml version="1.0" encoding="UTF-8"?>
# # <subsidiary_group> [...] </subsidiary_group>
#
# my_group.to_xml(:dasherize => true)
# # => <?xml version="1.0" encoding="UTF-8"?>
# # <subsidiary-group> [...] </subsidiary-group>
#
# my_group.to_xml(:skip_instruct => true)
# # => <subsidiary_group> [...] </subsidiary_group>
def to_xml(options={})
attributes.to_xml({:root => self.class.element_name}.merge(options))
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'}
#
# 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| 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 <tt>respond_to?</tt> 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 <tt>true</tt> to <tt>my_person.respond_to?("name")</tt>, <tt>my_person.respond_to?("name=")</tt>, and
# <tt>my_person.respond_to?("name?")</tt>.
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
returning connection.put(element_path(prefix_options), to_xml, self.class.headers) do |response|
load_attributes_from_response(response)
end
end
# Create (i.e., save to the remote service) the new resource.
def create
returning connection.post(collection_path, to_xml, self.class.headers) 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]
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
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
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