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 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 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:
HTTP Basic Authentication
- 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.
Certificate Authentication
- End point uses an X509 certificate for authentication. See ssl_options= for all options.
class Person < ActiveResource::Base self.site = "https://secure.api.people.com/" self.ssl_options = {:cert => OpenSSL::X509::Certificate.new(File.open(pem_file)) :key => OpenSSL::PKey::RSA.new(File.open(pem_file)), :ca_path => "/path/to/OpenSSL/formatted/CA_Certs", :verify_mode => OpenSSL::SSL::VERIFY_PEER} end
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
- 410 - ActiveResource::ResourceGone
- 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 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 or JSON 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 # or # PUT http://api.people.com:3000/people/1.json # is requested with invalid values, the response is: # # Response (422): # <errors type="array"><error>First cannot be empty</error></errors> # or # {"errors":["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 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.
- ==
- as_json
- clone
- collection_path
- collection_path
- connection
- connection
- create
- create
- delete
- destroy
- dup
- element_path
- element_path
- encode
- eql?
- exists?
- exists?
- find
- format
- format=
- hash
- headers
- id
- id=
- id_from_response
- load
- load_attributes_from_response
- new
- new?
- new_record?
- password
- password=
- prefix
- prefix=
- prefix_source
- proxy
- proxy=
- reload
- respond_to?
- save
- site
- site=
- ssl_options
- ssl_options=
- timeout
- timeout=
- to_param
- to_xml
- update
- user
- user=
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
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# File activeresource/lib/active_resource/base.rb, line 500 500: def collection_path(prefix_options = {}, query_options = nil) 501: prefix_options, query_options = split_options(prefix_options) if query_options.nil? 502: "#{prefix(prefix_options)}#{collection_name}.#{format.extension}#{query_string(query_options)}" 503: 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).
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# File activeresource/lib/active_resource/base.rb, line 385 385: def connection(refresh = false) 386: if defined?(@connection) || superclass == Object 387: @connection = Connection.new(site, format) if refresh || @connection.nil? 388: @connection.proxy = proxy if proxy 389: @connection.user = user if user 390: @connection.password = password if password 391: @connection.timeout = timeout if timeout 392: @connection.ssl_options = ssl_options if ssl_options 393: @connection 394: else 395: superclass.connection 396: end 397: end
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
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# File activeresource/lib/active_resource/base.rb, line 531 531: def create(attributes = {}) 532: self.new(attributes).tap { |resource| resource.save } 533: 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
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# File activeresource/lib/active_resource/base.rb, line 608 608: def delete(id, options = {}) 609: connection.delete(element_path(id, options)) 610: end
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 <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
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# File activeresource/lib/active_resource/base.rb, line 474 474: def element_path(id, prefix_options = {}, query_options = nil) 475: prefix_options, query_options = split_options(prefix_options) if query_options.nil? 476: "#{prefix(prefix_options)}#{collection_name}/#{id}.#{format.extension}#{query_string(query_options)}" 477: 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
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# File activeresource/lib/active_resource/base.rb, line 619 619: def exists?(id, options = {}) 620: if id 621: prefix_options, query_options = split_options(options[:params]) 622: path = element_path(id, prefix_options, query_options) 623: response = connection.head(path, headers) 624: response.code.to_i == 200 625: end 626: # id && !find_single(id, options).nil? 627: rescue ActiveResource::ResourceNotFound, ActiveResource::ResourceGone 628: false 629: 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
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# File activeresource/lib/active_resource/base.rb, line 581 581: def find(*arguments) 582: scope = arguments.slice!(0) 583: options = arguments.slice!(0) || {} 584: 585: case scope 586: when :all then find_every(options) 587: when :first then find_every(options).first 588: when :last then find_every(options).last 589: when :one then find_one(options) 590: else find_single(scope, options) 591: end 592: end
Returns the current format, default is ActiveResource::Formats::XmlFormat.
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# File activeresource/lib/active_resource/base.rb, line 338 338: def format 339: read_inheritable_attribute(:format) || ActiveResource::Formats[:xml] 340: 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.
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# File activeresource/lib/active_resource/base.rb, line 329 329: def format=(mime_type_reference_or_format) 330: format = mime_type_reference_or_format.is_a?(Symbol) ? 331: ActiveResource::Formats[mime_type_reference_or_format] : mime_type_reference_or_format 332: 333: write_inheritable_attribute(:format, format) 334: connection.format = format if site 335: end
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# File activeresource/lib/active_resource/base.rb, line 399 399: def headers 400: @headers ||= {} 401: end
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
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# File activeresource/lib/active_resource/base.rb, line 724 724: def initialize(attributes = {}) 725: @attributes = {} 726: @prefix_options = {} 727: load(attributes) 728: end
Gets the \password for REST HTTP authentication.
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# File activeresource/lib/active_resource/base.rb, line 305 305: def password 306: # Not using superclass_delegating_reader. See +site+ for explanation 307: if defined?(@password) 308: @password 309: elsif superclass != Object && superclass.password 310: superclass.password.dup.freeze 311: end 312: end
Sets the \password for REST HTTP authentication.
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# File activeresource/lib/active_resource/base.rb, line 315 315: def password=(password) 316: @connection = nil 317: @password = password 318: end
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.
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# File activeresource/lib/active_resource/base.rb, line 412 412: def prefix(options={}) 413: default = site.path 414: default << '/' unless default[-1..-1] == '/' 415: # generate the actual method based on the current site path 416: self.prefix = default 417: prefix(options) 418: end
Sets the \prefix for a resource‘s nested URL (e.g., prefix/collectionname/1.xml). Default value is site.path.
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# File activeresource/lib/active_resource/base.rb, line 429 429: def prefix=(value = '/') 430: # Replace :placeholders with '#{embedded options[:lookups]}' 431: prefix_call = value.gsub(/:\w+/) { |key| "\#{options[#{key}]}" } 432: 433: # Clear prefix parameters in case they have been cached 434: @prefix_parameters = nil 435: 436: # Redefine the new methods. 437: code, line = "def prefix_source() \"\#{value}\" end\ndef prefix(options={}) \"\#{prefix_call}\" end\n", __LINE__ + 1 438: silence_warnings { instance_eval code, __FILE__, line } 439: rescue 440: logger.error "Couldn't set prefix: #{$!}\n #{code}" 441: raise 442: 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.
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# File activeresource/lib/active_resource/base.rb, line 422 422: def prefix_source 423: prefix # generate #prefix and #prefix_source methods first 424: prefix_source 425: end
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# File activeresource/lib/active_resource/base.rb, line 273 273: def proxy 274: # Not using superclass_delegating_reader. See +site+ for explanation 275: if defined?(@proxy) 276: @proxy 277: elsif superclass != Object && superclass.proxy 278: superclass.proxy.dup.freeze 279: end 280: end
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# File activeresource/lib/active_resource/base.rb, line 283 283: def proxy=(proxy) 284: @connection = nil 285: @proxy = proxy.nil? ? nil : create_proxy_uri_from(proxy) 286: end
Gets the URI of the REST resources to map for this class. The site variable is required for Active Resource‘s mapping to work.
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# File activeresource/lib/active_resource/base.rb, line 236 236: def site 237: # Not using superclass_delegating_reader because don't want subclasses to modify superclass instance 238: # 239: # With superclass_delegating_reader 240: # 241: # Parent.site = 'http://anonymous@test.com' 242: # Subclass.site # => 'http://anonymous@test.com' 243: # Subclass.site.user = 'david' 244: # Parent.site # => 'http://david@test.com' 245: # 246: # Without superclass_delegating_reader (expected behaviour) 247: # 248: # Parent.site = 'http://anonymous@test.com' 249: # Subclass.site # => 'http://anonymous@test.com' 250: # Subclass.site.user = 'david' # => TypeError: can't modify frozen object 251: # 252: if defined?(@site) 253: @site 254: elsif superclass != Object && superclass.site 255: superclass.site.dup.freeze 256: end 257: 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.
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# File activeresource/lib/active_resource/base.rb, line 261 261: def site=(site) 262: @connection = nil 263: if site.nil? 264: @site = nil 265: else 266: @site = create_site_uri_from(site) 267: @user = URI.decode(@site.user) if @site.user 268: @password = URI.decode(@site.password) if @site.password 269: end 270: end
Returns the SSL options hash.
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# File activeresource/lib/active_resource/base.rb, line 374 374: def ssl_options 375: if defined?(@ssl_options) 376: @ssl_options 377: elsif superclass != Object && superclass.ssl_options 378: superclass.ssl_options 379: end 380: end
Options that will get applied to an SSL connection.
- :key - An OpenSSL::PKey::RSA or OpenSSL::PKey::DSA object.
- :cert - An OpenSSL::X509::Certificate object as client certificate
- :ca_file - Path to a CA certification file in PEM format. The file can contrain several CA certificates.
- :ca_path - Path of a CA certification directory containing certifications in PEM format.
- :verify_mode - Flags for server the certification verification at begining of SSL/TLS session. (OpenSSL::SSL::VERIFY_NONE or OpenSSL::SSL::VERIFY_PEER is acceptable)
- :verify_callback - The verify callback for the server certification verification.
- :verify_depth - The maximum depth for the certificate chain verification.
- :cert_store - OpenSSL::X509::Store to verify peer certificate.
- :ssl_timeout -The SSL timeout in seconds.
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# File activeresource/lib/active_resource/base.rb, line 368 368: def ssl_options=(opts={}) 369: @connection = nil 370: @ssl_options = opts 371: end
Gets the number of seconds after which requests to the REST API should time out.
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# File activeresource/lib/active_resource/base.rb, line 349 349: def timeout 350: if defined?(@timeout) 351: @timeout 352: elsif superclass != Object && superclass.timeout 353: superclass.timeout 354: end 355: end
Sets the number of seconds after which requests to the REST API should time out.
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# File activeresource/lib/active_resource/base.rb, line 343 343: def timeout=(timeout) 344: @connection = nil 345: @timeout = timeout 346: end
Gets the \user for REST HTTP authentication.
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# File activeresource/lib/active_resource/base.rb, line 289 289: def user 290: # Not using superclass_delegating_reader. See +site+ for explanation 291: if defined?(@user) 292: @user 293: elsif superclass != Object && superclass.user 294: superclass.user.dup.freeze 295: end 296: end
Sets the \user for REST HTTP authentication.
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# File activeresource/lib/active_resource/base.rb, line 299 299: def user=(user) 300: @connection = nil 301: @user = user 302: 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
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# File activeresource/lib/active_resource/base.rb, line 820 820: def ==(other) 821: other.equal?(self) || (other.instance_of?(self.class) && other.id == id && other.prefix_options == prefix_options) 822: end
Coerces to a hash for JSON encoding.
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"}
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# File activeresource/lib/active_resource/base.rb, line 967 967: def as_json(options = nil) 968: attributes.as_json(options) 969: 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"}
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# File activeresource/lib/active_resource/base.rb, line 750 750: def clone 751: # Clone all attributes except the pk and any nested ARes 752: cloned = attributes.reject {|k,v| k == self.class.primary_key || v.is_a?(ActiveResource::Base)}.inject({}) do |attrs, (k, v)| 753: attrs[k] = v.clone 754: attrs 755: end 756: # Form the new resource - bypass initialize of resource with 'new' as that will call 'load' which 757: # attempts to convert hashes into member objects and arrays into collections of objects. We want 758: # the raw objects to be cloned so we bypass load by directly setting the attributes hash. 759: resource = self.class.new({}) 760: resource.prefix_options = self.prefix_options 761: resource.send :instance_variable_set, '@attributes', cloned 762: resource 763: 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)
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# File activeresource/lib/active_resource/base.rb, line 883 883: def destroy 884: connection.delete(element_path, self.class.headers) 885: 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
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# File activeresource/lib/active_resource/base.rb, line 847 847: def dup 848: self.class.new.tap do |resource| 849: resource.attributes = @attributes 850: resource.prefix_options = @prefix_options 851: end 852: 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.
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# File activeresource/lib/active_resource/base.rb, line 974 974: def encode(options={}) 975: case self.class.format 976: when ActiveResource::Formats[:xml] 977: self.class.format.encode(attributes, {:root => self.class.element_name}.merge(options)) 978: when ActiveResource::Formats::JsonFormat 979: if ActiveResource::Base.include_root_in_json 980: self.class.format.encode({self.class.element_name => attributes}, options) 981: else 982: self.class.format.encode(attributes, options) 983: end 984: else 985: self.class.format.encode(attributes, options) 986: end 987: end
Tests for equality (delegates to ==).
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# File activeresource/lib/active_resource/base.rb, line 825 825: def eql?(other) 826: self == other 827: 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
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# File activeresource/lib/active_resource/base.rb, line 903 903: def exists? 904: !new? && self.class.exists?(to_param, :params => prefix_options) 905: 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)]
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# File activeresource/lib/active_resource/base.rb, line 831 831: def hash 832: id.hash 833: end
Gets the \id attribute of the resource.
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# File activeresource/lib/active_resource/base.rb, line 784 784: def id 785: attributes[self.class.primary_key] 786: end
Sets the \id attribute of the resource.
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# File activeresource/lib/active_resource/base.rb, line 789 789: def id=(id) 790: attributes[self.class.primary_key] = id 791: 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
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# File activeresource/lib/active_resource/base.rb, line 1025 1025: def load(attributes) 1026: raise ArgumentError, "expected an attributes Hash, got #{attributes.inspect}" unless attributes.is_a?(Hash) 1027: @prefix_options, attributes = split_options(attributes) 1028: attributes.each do |key, value| 1029: @attributes[key.to_s] = 1030: case value 1031: when Array 1032: resource = find_or_create_resource_for_collection(key) 1033: value.map do |attrs| 1034: if attrs.is_a?(String) || attrs.is_a?(Numeric) 1035: attrs.duplicable? ? attrs.dup : attrs 1036: else 1037: resource.new(attrs) 1038: end 1039: end 1040: when Hash 1041: resource = find_or_create_resource_for(key) 1042: resource.new(value) 1043: else 1044: value.dup rescue value 1045: end 1046: end 1047: self 1048: 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
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# File activeresource/lib/active_resource/base.rb, line 778 778: def new? 779: id.nil? 780: end
Alias for new?
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"
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# File activeresource/lib/active_resource/base.rb, line 1000 1000: def reload 1001: self.load(self.class.find(to_param, :params => @prefix_options).attributes) 1002: end
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?).
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# File activeresource/lib/active_resource/base.rb, line 1056 1056: def respond_to?(method, include_priv = false) 1057: method_name = method.to_s 1058: if attributes.nil? 1059: return super 1060: elsif attributes.has_key?(method_name) 1061: return true 1062: elsif ['?','='].include?(method_name.last) && attributes.has_key?(method_name.first(-1)) 1063: return true 1064: end 1065: # super must be called at the end of the method, because the inherited respond_to? 1066: # would return true for generated readers, even if the attribute wasn't present 1067: super 1068: 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)
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# File activeresource/lib/active_resource/base.rb, line 867 867: def save 868: new? ? create : update 869: end
Allows Active Resource objects to be used as parameters in Action Pack URL generation.
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# File activeresource/lib/active_resource/base.rb, line 794 794: def to_param 795: id && id.to_s 796: 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 true. The default can be set to false by setting the module attribute ActiveSupport.dasherize_xml = false in an initializer. Because save uses this method, and there are no options on save, then you will have to set the default if you don‘t want underscores in element names to become dashes when the resource is saved. This is important when integrating with non-Rails applications.
- :camelize - Boolean option to determine whether or not element names should be converted to camel case, e.g some_name to SomeName. Default is false. Like :dasherize you can change the default by setting the module attribute ActiveSupport.camelise_xml = true in an initializer.
- :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 # => <?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>
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# File activeresource/lib/active_resource/base.rb, line 939 939: def to_xml(options={}) 940: attributes.to_xml({:root => self.class.element_name}.merge(options)) 941: end
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# File activeresource/lib/active_resource/base.rb, line 1106 1106: def collection_path(options = nil) 1107: self.class.collection_path(options || prefix_options) 1108: end
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# File activeresource/lib/active_resource/base.rb, line 1072 1072: def connection(refresh = false) 1073: self.class.connection(refresh) 1074: end
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# File activeresource/lib/active_resource/base.rb, line 1084 1084: def create 1085: connection.post(collection_path, encode, self.class.headers).tap do |response| 1086: self.id = id_from_response(response) 1087: load_attributes_from_response(response) 1088: end 1089: end
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# File activeresource/lib/active_resource/base.rb, line 1102 1102: def element_path(options = nil) 1103: self.class.element_path(to_param, options || prefix_options) 1104: end
Takes a response from a typical create post and pulls the ID out
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# File activeresource/lib/active_resource/base.rb, line 1098 1098: def id_from_response(response) 1099: response['Location'][/\/([^\/]*?)(\.\w+)?$/, 1] if response['Location'] 1100: end
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# File activeresource/lib/active_resource/base.rb, line 1091 1091: def load_attributes_from_response(response) 1092: if response['Content-Length'] != "0" && response.body.strip.size > 0 1093: load(self.class.format.decode(response.body)) 1094: end 1095: end
Update the resource on the remote service.
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# File activeresource/lib/active_resource/base.rb, line 1077 1077: def update 1078: connection.put(element_path(prefix_options), encode, self.class.headers).tap do |response| 1079: load_attributes_from_response(response) 1080: end 1081: end