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 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 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 # * 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 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 # 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 URL's (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 = {}) 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. # # * :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 = {}) 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 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.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 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 # 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. # # * :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 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'} # # 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 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 returning connection.put(element_path(prefix_options), encode, 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, encode, 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