Class: ActiveResource::Base

Inherits:
Object
  • Object
show all
Extended by:
ActiveModel::Naming, Associations
Includes:
ActiveModel::Conversion, ActiveModel::Serializers::JSON, ActiveModel::Serializers::Xml, Callbacks, CustomMethods, Observing, Reflection, Validations
Defined in:
lib/active_resource/base.rb,
lib/active_resource/base.rb

Overview

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 its README.

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 = "https://api.people.com"
end

Now the Person class is mapped to RESTful resources located at https://api.people.com/people/, and you can now use Active Resource’s life cycle 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 = "https://api.people.com"
  self.element_name = "person"
end

If your Active Resource object is required to use an HTTP proxy you can set the proxy value which holds a URI.

class PersonResource < ActiveResource::Base
  self.site = "https://api.people.com"
  self.proxy = "https://user:[email protected]:8080"
end

Life cycle 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 life cycle methods for database records. You can read more about each of these methods in their respective documentation.

Custom REST methods

Since simple CRUD/life cycle 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.json.
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.json?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.json.
Person.get(:positions)
# => [{:name => 'Manager'}, {:name => 'Clerk'}]

# DELETE to 'fire' a person, i.e. DELETE /people/1/fire.json.
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 = "https://api.people.com"
   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 require authentication. The HTTP spec describes two ways to make requests with a username and password (see RFC 2617).

Basic authentication simply sends a username and password along with HTTP requests. These sensitive credentials are sent unencrypted, visible to any onlooker, so this scheme should only be used with SSL.

Digest authentication sends a crytographic hash of the username, password, HTTP method, URI, and a single-use secret key provided by the server. Sensitive credentials aren’t visible to onlookers, so digest authentication doesn’t require SSL. However, this doesn’t mean the connection is secure! Just the username and password.

(You really, really want to use SSL. There’s little reason not to.)

Picking an authentication scheme

Basic authentication is the default. To switch to digest authentication, set auth_type to :digest:

class Person < ActiveResource::Base
  self.auth_type = :digest
end

Setting the username and password

Set user and password on the class, or include them in the site URL.

class Person < ActiveResource::Base
  # Set user and password directly:
  self.user = "ryan"
  self.password = "password"

  # Or include them in the site:
  self.site = "https://ryan:[email protected]"
end

Certificate Authentication

You can also authenticate using an X509 certificate. See ssl_options= for all options.

class Person < ActiveResource::Base
  self.site = "https://secure.api.people.com/"

  File.open(pem_file_path, 'rb') do |pem_file|
    self.ssl_options = {
      cert:        OpenSSL::X509::Certificate.new(pem_file),
      key:         OpenSSL::PKey::RSA.new(pem_file),
      ca_path:     "/path/to/OpenSSL/formatted/CA_Certs",
      verify_mode: OpenSSL::SSL::VERIFY_PEER }
  end
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 https://api.people.com/people/999.json
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 exceptions, other than these redirects:

  • 301, 302, 303, 307 - 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

When a GET is requested for a nested resource and you don’t provide the prefix_param an ActiveResource::MissingPrefixParam will be raised.

class Comment < ActiveResource::Base
  self.site = "https://someip.com/posts/:post_id"
end

Comment.find(1)
# => ActiveResource::MissingPrefixParam: post_id prefix_option is missing

Validation errors

Active Resource supports validations on resources and will return errors if any of these validations fail (e.g., “First name can not be blank” and so on). These types of errors are denoted in the response by a response code of 422 and an JSON or 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 https://api.people.com/people/1.xml
# or
# PUT https://api.people.com/people/1.json
# is requested with invalid values, the response is:
#
# Response (422):
# <errors><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']

For backwards-compatibility with older endpoints, the following formats are also supported in JSON responses:

# {"errors":['First cannot be empty']}
#   This was the required format for previous versions of ActiveResource
# {"first":["cannot be empty"]}
#   This was the default format produced by respond_with in ActionController <3.2.1

Parsing either of these formats will result in a deprecation warning.

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 = "https://api.people.com"
  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.

Constant Summary

Constants included from Callbacks

Callbacks::CALLBACKS

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Associations

belongs_to, defines_belongs_to_finder_method, defines_has_many_finder_method, defines_has_one_finder_method, has_many, has_one

Methods included from CustomMethods

#delete, #get, #patch, #post, #put

Methods included from Validations

#errors, #load_remote_errors, #save_with_validation, #valid?

Constructor Details

#initialize(attributes = {}, persisted = false) ⇒ Base

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 'lib/active_resource/base.rb', line 1070

def initialize(attributes = {}, persisted = false)
  @attributes     = {}.with_indifferent_access
  @prefix_options = {}
  @persisted = persisted
  load(attributes, false, persisted)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_symbol, *arguments) ⇒ Object (private)

:nodoc:



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# File 'lib/active_resource/base.rb', line 1534

def method_missing(method_symbol, *arguments) #:nodoc:
  method_name = method_symbol.to_s

  if method_name =~ /(=|\?)$/
    case $1
    when "="
      attributes[$`] = arguments.first
    when "?"
      attributes[$`]
    end
  else
    return attributes[method_name] if attributes.include?(method_name)
    # not set right now but we know about it
    return nil if known_attributes.include?(method_name)
    super
  end
end

Class Attribute Details

.collection_name ⇒ Object 



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# File 'lib/active_resource/base.rb', line 621

def collection_name
  @collection_name ||= ActiveSupport::Inflector.pluralize(element_name)
end

.element_name ⇒ Object 



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# File 'lib/active_resource/base.rb', line 615

def element_name
  @element_name ||= model_name.element
end

.primary_key ⇒ Object 



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# File 'lib/active_resource/base.rb', line 627

def primary_key
  if defined?(@primary_key)
    @primary_key
  elsif superclass != Object && superclass.primary_key
    primary_key = superclass.primary_key
    return primary_key if primary_key.is_a?(Symbol)
    primary_key.dup.freeze
  else
    'id'
  end
end

Instance Attribute Details

#attributes ⇒ Object

:nodoc:



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# File 'lib/active_resource/base.rb', line 1041

def attributes
  @attributes
end

#prefix_options ⇒ Object

:nodoc:



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# File 'lib/active_resource/base.rb', line 1042

def prefix_options
  @prefix_options
end

Class Method Details

.all(*args) ⇒ Object

This is an alias for find(:all). You can pass in all the same arguments to this method as you can to find(:all)



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# File 'lib/active_resource/base.rb', line 898

def all(*args)
  find(:all, *args)
end

.auth_type ⇒ Object 



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# File 'lib/active_resource/base.rb', line 502

def auth_type
  if defined?(@auth_type)
    @auth_type
  end
end

.auth_type=(auth_type) ⇒ Object 



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# File 'lib/active_resource/base.rb', line 508

def auth_type=(auth_type)
  @connection = nil
  @auth_type = auth_type
end

.build(attributes = {}) ⇒ Object

Builds a new, unsaved record using the default values from the remote server so that it can be used with RESTful forms.

Options

  • attributes - A hash that overrides the default values from the server.

Returns the new resource instance.



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# File 'lib/active_resource/base.rb', line 776

def build(attributes = {})
  attrs = self.format.decode(connection.get("#{new_element_path(attributes)}", headers).body)
  self.new(attrs)
end

.collection_parser ⇒ Object 



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# File 'lib/active_resource/base.rb', line 541

def collection_parser
  self._collection_parser || ActiveResource::Collection
end

.collection_parser=(parser_instance) ⇒ Object

Sets the parser to use when a collection is returned. The parser must be Enumerable.



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# File 'lib/active_resource/base.rb', line 536

def collection_parser=(parser_instance)
  parser_instance = parser_instance.constantize if parser_instance.is_a?(String)
  self._collection_parser = parser_instance
end

.collection_path(prefix_options = {}, query_options = nil) ⇒ Object

Gets the collection path for the REST resources. If the query_options parameter is omitted, Rails will split from the prefix_options.

Options

  • prefix_options - A hash to add a prefix to the request for nested URLs (e.g., :account_id => 19 would yield a URL like /accounts/19/purchases.json).

  • query_options - A hash to add items to the query string for the request.

Examples

Post.collection_path
# => /posts.json

Comment.collection_path(:post_id => 5)
# => /posts/5/comments.json

Comment.collection_path(:post_id => 5, :active => 1)
# => /posts/5/comments.json?active=1

Comment.collection_path({:post_id => 5}, {:active => 1})
# => /posts/5/comments.json?active=1



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# File 'lib/active_resource/base.rb', line 760

def collection_path(prefix_options = {}, query_options = nil)
  check_prefix_options(prefix_options)
  prefix_options, query_options = split_options(prefix_options) if query_options.nil?
  "#{prefix(prefix_options)}#{collection_name}#{format_extension}#{query_string(query_options)}"
end

.connection(refresh = false) ⇒ Object

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 'lib/active_resource/base.rb', line 588

def connection(refresh = false)
  if defined?(@connection) || superclass == Object
    @connection = Connection.new(site, format) if refresh || @connection.nil?
    @connection.proxy = proxy if proxy
    @connection.user = user if user
    @connection.password = password if password
    @connection.auth_type = auth_type if auth_type
    @connection.timeout = timeout if timeout
    @connection.ssl_options = ssl_options if ssl_options
    @connection
  else
    superclass.connection
  end
end

.create(attributes = {}) ⇒ Object

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 => '[email protected]', :enabled => true)
my_person = Person.find(:first)
my_person.email # => [email protected]

dhh = Person.create(:name => 'David', :email => '[email protected]', :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 => '[email protected]', :enabled => true)
that_guy.valid? # => false
that_guy.new?   # => true



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# File 'lib/active_resource/base.rb', line 805

def create(attributes = {})
  self.new(attributes).tap { |resource| resource.save }
end

.delete(id, options = {}) ⇒ Object

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.json
Event.delete(params[:id]) # sends DELETE /events/5



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# File 'lib/active_resource/base.rb', line 922

def delete(id, options = {})
  connection.delete(element_path(id, options), headers)
end

.element_path(id, prefix_options = {}, query_options = nil) ⇒ Object

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.json).

query_options - A hash to add items to the query string for the request.

Examples

Post.element_path(1)
# => /posts/1.json

class Comment < ActiveResource::Base
  self.site = "https://37s.sunrise.com/posts/:post_id"
end

Comment.element_path(1, :post_id => 5)
# => /posts/5/comments/1.json

Comment.element_path(1, :post_id => 5, :active => 1)
# => /posts/5/comments/1.json?active=1

Comment.element_path(1, {:post_id => 5}, {:active => 1})
# => /posts/5/comments/1.json?active=1



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# File 'lib/active_resource/base.rb', line 712

def element_path(id, prefix_options = {}, query_options = nil)
  check_prefix_options(prefix_options)

  prefix_options, query_options = split_options(prefix_options) if query_options.nil?
  "#{prefix(prefix_options)}#{collection_name}/#{URI.parser.escape id.to_s}#{format_extension}#{query_string(query_options)}"
end

.exists?(id, options = {}) ⇒ Boolean

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

Returns:

  • (Boolean) 


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# File 'lib/active_resource/base.rb', line 933

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, ActiveResource::ResourceGone
  false
end

.find(*arguments) ⇒ Object

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.json

Person.find(:all)
# => GET /people.json

Person.find(:all, :params => { :title => "CEO" })
# => GET /people.json?title=CEO

Person.find(:first, :from => :managers)
# => GET /people/managers.json

Person.find(:last, :from => :managers)
# => GET /people/managers.json

Person.find(:all, :from => "/companies/1/people.json")
# => GET /companies/1/people.json

Person.find(:one, :from => :leader)
# => GET /people/leader.json

Person.find(:all, :from => :developers, :params => { :language => 'ruby' })
# => GET /people/developers.json?language=ruby

Person.find(:one, :from => "/companies/1/manager.json")
# => GET /companies/1/manager.json

StreetAddress.find(1, :params => { :person_id => 1 })
# => GET /people/1/street_addresses/1.json

Failure or missing data

A failure to find the requested object raises a ResourceNotFound exception if the find was called with an id. With any other scope, find returns nil when no data is returned.

Person.find(1)
# => raises ResourceNotFound

Person.find(:all)
Person.find(:first)
Person.find(:last)
# => nil



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# File 'lib/active_resource/base.rb', line 868

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

.first(*args) ⇒ Object

A convenience wrapper for find(:first, *args). You can pass in all the same arguments to this method as you can to find(:first).



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# File 'lib/active_resource/base.rb', line 885

def first(*args)
  find(:first, *args)
end

.format ⇒ Object

Returns the current format, default is ActiveResource::Formats::JsonFormat.



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# File 'lib/active_resource/base.rb', line 531

def format
  self._format || ActiveResource::Formats::JsonFormat
end

.format=(mime_type_reference_or_format) ⇒ Object

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 :json.



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# File 'lib/active_resource/base.rb', line 522

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

  self._format = format
  connection.format = format if site
end

.format_extension ⇒ Object 



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# File 'lib/active_resource/base.rb', line 682

def format_extension
  include_format_in_path ? ".#{format.extension}" : ""
end

.headers ⇒ Object 



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# File 'lib/active_resource/base.rb', line 603

def headers
  @headers ||= {}

  if superclass != Object && superclass.headers
    @headers = superclass.headers.merge(@headers)
  else
    @headers
  end
end

.known_attributes ⇒ Object

Returns the list of known attributes for this resource, gathered from the provided schema Attributes that are known will cause your resource to return ‘true’ when respond_to? is called on them. A known attribute will return nil if not set (rather than MethodNotFound); thus known attributes can be used with validates_presence_of without a getter-method.



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# File 'lib/active_resource/base.rb', line 412

def known_attributes
  @known_attributes ||= []
end

.last(*args) ⇒ Object

A convenience wrapper for find(:last, *args). You can pass in all the same arguments to this method as you can to find(:last).



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# File 'lib/active_resource/base.rb', line 892

def last(*args)
  find(:last, *args)
end

.new_element_path(prefix_options = {}) ⇒ Object

Gets the new element path for REST resources.

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/new.json).

Examples

Post.new_element_path
# => /posts/new.json

class Comment < ActiveResource::Base
  self.site = "https://37s.sunrise.com/posts/:post_id"
end

Comment.collection_path(:post_id => 5)
# => /posts/5/comments/new.json



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# File 'lib/active_resource/base.rb', line 735

def new_element_path(prefix_options = {})
  "#{prefix(prefix_options)}#{collection_name}/new#{format_extension}"
end

.password ⇒ Object

Gets the password for REST HTTP authentication.



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# File 'lib/active_resource/base.rb', line 487

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

.password=(password) ⇒ Object

Sets the password for REST HTTP authentication.



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# File 'lib/active_resource/base.rb', line 497

def password=(password)
  @connection = nil
  @password = password
end

.prefix(options = {}) ⇒ Object

Gets the prefix for a resource’s nested URL (e.g., prefix/collectionname/1.json) This method is regenerated at runtime based on what the prefix is set to.



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# File 'lib/active_resource/base.rb', line 641

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

.prefix=(value = '/') ⇒ Object Also known as: set_prefix

Sets the prefix for a resource’s nested URL (e.g., prefix/collectionname/1.json). Default value is site.path.



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# File 'lib/active_resource/base.rb', line 658

def prefix=(value = '/')
  # Replace :placeholders with '#{embedded options[:lookups]}'
  prefix_call = value.gsub(/:\w+/) { |key| "\#{URI.parser.escape options[#{key}].to_s}" }

  # Clear prefix parameters in case they have been cached
  @prefix_parameters = nil

  silence_warnings do
    # Redefine the new methods.
    instance_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1
      def prefix_source() "#{value}" end
      def prefix(options={}) "#{prefix_call}" end
    RUBY_EVAL
  end
rescue Exception => e
  logger.error "Couldn't set prefix: #{e}\n  #{code}" if logger
  raise
end

.prefix_source ⇒ Object

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 'lib/active_resource/base.rb', line 651

def prefix_source
  prefix # generate #prefix and #prefix_source methods first
  prefix_source
end

.proxy ⇒ Object

Gets the proxy variable if a proxy is required



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# File 'lib/active_resource/base.rb', line 455

def proxy
  # Not using superclass_delegating_reader. See +site+ for explanation
  if defined?(@proxy)
    @proxy
  elsif superclass != Object && superclass.proxy
    superclass.proxy.dup.freeze
  end
end

.proxy=(proxy) ⇒ Object

Sets the URI of the http proxy to the value in the proxy argument.



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# File 'lib/active_resource/base.rb', line 465

def proxy=(proxy)
  @connection = nil
  @proxy = proxy.nil? ? nil : create_proxy_uri_from(proxy)
end

.schema(&block) ⇒ Object

Creates a schema for this resource - setting the attributes that are known prior to fetching an instance from the remote system.

The schema helps define the set of known_attributes of the current resource.

There is no need to specify a schema for your Active Resource. If you do not, the known_attributes will be guessed from the instance attributes returned when an instance is fetched from the remote system.

example:

class Person < ActiveResource::Base
  schema do
    # define each attribute separately
    attribute 'name', :string

    # or use the convenience methods and pass >=1 attribute names
    string  'eye_color', 'hair_color'
    integer 'age'
    float   'height', 'weight'

    # unsupported types should be left as strings
    # overload the accessor methods if you need to convert them
    attribute 'created_at', 'string'
  end
end

p = Person.new
p.respond_to? :name   # => true
p.respond_to? :age    # => true
p.name                # => nil
p.age                 # => nil

j = Person.find_by_name('John')
<person><name>John</name><age>34</age><num_children>3</num_children></person>
j.respond_to? :name   # => true
j.respond_to? :age    # => true
j.name                # => 'John'
j.age                 # => '34'  # note this is a string!
j.num_children        # => '3'  # note this is a string!

p.num_children        # => NoMethodError

Attribute-types must be one of: string, integer, float

Note: at present the attribute-type doesn’t do anything, but stay tuned… Shortly it will also cast the value of the returned attribute. ie: j.age # => 34 # cast to an integer j.weight # => ‘65’ # still a string!



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# File 'lib/active_resource/base.rb', line 351

def schema(&block)
  if block_given?
    schema_definition = Schema.new
    schema_definition.instance_eval(&block)

    # skip out if we didn't define anything
    return unless schema_definition.attrs.present?

    @schema ||= {}.with_indifferent_access
    @known_attributes ||= []

    schema_definition.attrs.each do |k,v|
      @schema[k] = v
      @known_attributes << k
    end

    schema
  else
    @schema ||= nil
  end
end

.schema=(the_schema) ⇒ Object

Alternative, direct way to specify a schema for this Resource. schema is more flexible, but this is quick for a very simple schema.

Pass the schema as a hash with the keys being the attribute-names and the value being one of the accepted attribute types (as defined in schema)

example:

class Person < ActiveResource::Base
  schema = {'name' => :string, 'age' => :integer }
end

The keys/values can be strings or symbols. They will be converted to strings.

Raises:

  • (ArgumentError) 


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# File 'lib/active_resource/base.rb', line 390

def schema=(the_schema)
  unless the_schema.present?
    # purposefully nulling out the schema
    @schema = nil
    @known_attributes = []
    return
  end

  raise ArgumentError, "Expected a hash" unless the_schema.kind_of? Hash

  schema do
    the_schema.each {|k,v| attribute(k,v) }
  end
end

.site ⇒ Object

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 'lib/active_resource/base.rb', line 418

def site
  # Not using superclass_delegating_reader because don't want subclasses to modify superclass instance
  #
  # With superclass_delegating_reader
  #
  #   Parent.site = 'https://[email protected]'
  #   Subclass.site # => 'https://[email protected]'
  #   Subclass.site.user = 'david'
  #   Parent.site # => 'https://[email protected]'
  #
  # Without superclass_delegating_reader (expected behavior)
  #
  #   Parent.site = 'https://[email protected]'
  #   Subclass.site # => 'https://[email protected]'
  #   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

.site=(site) ⇒ Object

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 'lib/active_resource/base.rb', line 443

def site=(site)
  @connection = nil
  if site.nil?
    @site = nil
  else
    @site = create_site_uri_from(site)
    @user = URI.parser.unescape(@site.user) if @site.user
    @password = URI.parser.unescape(@site.password) if @site.password
  end
end

.ssl_options ⇒ Object

Returns the SSL options hash.



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# File 'lib/active_resource/base.rb', line 577

def ssl_options
  if defined?(@ssl_options)
    @ssl_options
  elsif superclass != Object && superclass.ssl_options
    superclass.ssl_options
  end
end

.ssl_options=(options) ⇒ Object

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 contain 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 beginning 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 'lib/active_resource/base.rb', line 571

def ssl_options=(options)
  @connection   = nil
  @ssl_options  = options
end

.timeout ⇒ Object

Gets the number of seconds after which requests to the REST API should time out.



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# File 'lib/active_resource/base.rb', line 552

def timeout
  if defined?(@timeout)
    @timeout
  elsif superclass != Object && superclass.timeout
    superclass.timeout
  end
end

.timeout=(timeout) ⇒ Object

Sets the number of seconds after which requests to the REST API should time out.



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# File 'lib/active_resource/base.rb', line 546

def timeout=(timeout)
  @connection = nil
  @timeout = timeout
end

.user ⇒ Object

Gets the user for REST HTTP authentication.



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# File 'lib/active_resource/base.rb', line 471

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

.user=(user) ⇒ Object

Sets the user for REST HTTP authentication.



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# File 'lib/active_resource/base.rb', line 481

def user=(user)
  @connection = nil
  @user = user
end

.where(clauses = {}) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/active_resource/base.rb', line 902

def where(clauses = {})
  raise ArgumentError, "expected a clauses Hash, got #{clauses.inspect}" unless clauses.is_a? Hash
  find(:all, :params => clauses)
end

Instance Method Details

#==(other) ⇒ Object

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 'lib/active_resource/base.rb', line 1175

def ==(other)
  other.equal?(self) || (other.instance_of?(self.class) && other.id == id && other.prefix_options == prefix_options)
end

#clone ⇒ Object

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 'lib/active_resource/base.rb', line 1097

def clone
  # Clone all attributes except the pk and any nested ARes
  cloned = Hash[attributes.reject {|k,v| k == self.class.primary_key || v.is_a?(ActiveResource::Base)}.map { |k, v| [k, v.clone] }]
  # 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

#destroy ⇒ Object

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 'lib/active_resource/base.rb', line 1257

def destroy
  run_callbacks :destroy do
    connection.delete(element_path, self.class.headers)
  end
end

#dup ⇒ Object

Duplicates the current resource without saving it.

Examples

my_invoice = Invoice.create(:customer => 'That Company')
next_invoice = my_invoice.dup
next_invoice.new? # => true

next_invoice.save
next_invoice == my_invoice # => false (different id attributes)

my_invoice.customer   # => That Company
next_invoice.customer # => That Company



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# File 'lib/active_resource/base.rb', line 1202

def dup
  self.class.new.tap do |resource|
    resource.attributes     = @attributes
    resource.prefix_options = @prefix_options
  end
end

#encode(options = {}) ⇒ Object

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 'lib/active_resource/base.rb', line 1286

def encode(options={})
  send("to_#{self.class.format.extension}", options)
end

#eql?(other) ⇒ Boolean

Tests for equality (delegates to ==).

Returns:

  • (Boolean) 


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# File 'lib/active_resource/base.rb', line 1180

def eql?(other)
  self == other
end

#exists? ⇒ Boolean

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

Returns:

  • (Boolean) 


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# File 'lib/active_resource/base.rb', line 1279

def exists?
  !new? && self.class.exists?(to_param, :params => prefix_options)
end

#hash ⇒ Object

Delegates to id in order to allow two resources of the same type and id to work with something like:

[(a = Person.find 1), (b = Person.find 2)] & [(c = Person.find 1), (d = Person.find 4)] # => [a]



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# File 'lib/active_resource/base.rb', line 1186

def hash
  id.hash
end

#id ⇒ Object

Gets the \id attribute of the resource.



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# File 'lib/active_resource/base.rb', line 1144

def id
  attributes[self.class.primary_key]
end

#id=(id) ⇒ Object

Sets the \id attribute of the resource.



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# File 'lib/active_resource/base.rb', line 1149

def id=(id)
  attributes[self.class.primary_key] = id
end

#known_attributes ⇒ Object

This is a list of known attributes for this resource. Either gathered from the provided schema, or from the attributes set on this instance after it has been fetched from the remote system.



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# File 'lib/active_resource/base.rb', line 1054

def known_attributes
  (self.class.known_attributes + self.attributes.keys.map(&:to_s)).uniq
end

#load(attributes, remove_root = false, persisted = false) ⇒ Object

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

Raises:

  • (ArgumentError) 


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# File 'lib/active_resource/base.rb', line 1326

def load(attributes, remove_root = false, persisted = false)
  raise ArgumentError, "expected an attributes Hash, got #{attributes.inspect}" unless attributes.is_a?(Hash)
  @prefix_options, attributes = split_options(attributes)

  if attributes.keys.size == 1
    remove_root = self.class.element_name == attributes.keys.first.to_s
  end

  attributes = Formats.remove_root(attributes) if remove_root

  attributes.each do |key, value|
    @attributes[key.to_s] =
      case value
        when Array
          resource = nil
          value.map do |attrs|
            if attrs.is_a?(Hash)
              resource ||= find_or_create_resource_for_collection(key)
              resource.new(attrs, persisted)
            else
              attrs.duplicable? ? attrs.dup : attrs
            end
          end
        when Hash
          resource = find_or_create_resource_for(key)
          resource.new(value, persisted)
        else
          value.duplicable? ? value.dup : value
      end
  end
  self
end

#logger ⇒ Object

:singleton-method: The logger for diagnosing and tracing Active Resource calls.



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# File 'lib/active_resource/base.rb', line 290

cattr_accessor :logger

#new? ⇒ Boolean Also known as: new_record?

Returns true if this object hasn’t yet been saved, otherwise, returns false.

Examples

not_new = Computer.create(:brand => 'Apple', :make => 'MacBook', :vendor => 'MacMall')
not_new.new? # => false

is_new = Computer.new(:brand => 'IBM', :make => 'Thinkpad', :vendor => 'IBM')
is_new.new? # => true

is_new.save
is_new.new? # => false

Returns:

  • (Boolean) 


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# File 'lib/active_resource/base.rb', line 1122

def new?
  !persisted?
end

#persisted? ⇒ Boolean

Returns true if this object has been saved, otherwise returns false.

Examples

persisted = Computer.create(:brand => 'Apple', :make => 'MacBook', :vendor => 'MacMall')
persisted.persisted? # => true

not_persisted = Computer.new(:brand => 'IBM', :make => 'Thinkpad', :vendor => 'IBM')
not_persisted.persisted? # => false

not_persisted.save
not_persisted.persisted? # => true

Returns:

  • (Boolean) 


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# File 'lib/active_resource/base.rb', line 1139

def persisted?
  @persisted
end

#reload ⇒ Object

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 'lib/active_resource/base.rb', line 1301

def reload
  self.load(self.class.find(to_param, :params => @prefix_options).attributes, false, true)
end

#respond_to?(method, include_priv = false) ⇒ Boolean

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?).

Returns:

  • (Boolean) 


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# File 'lib/active_resource/base.rb', line 1395

def respond_to?(method, include_priv = false)
  method_name = method.to_s
  if attributes.nil?
    super
  elsif known_attributes.include?(method_name)
    true
  elsif method_name =~ /(?:=|\?)$/ && attributes.include?($`)
    true
  else
    # 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
end

#respond_to_without_attributes? ⇒ Object

For checking respond_to? without searching the attributes (which is faster).



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# File 'lib/active_resource/base.rb', line 1390

alias_method :respond_to_without_attributes?, :respond_to?

#save ⇒ Object

Saves (POST) or updates (PUT) a resource. Delegates to create if the object is new, update if it exists. If the response to the save includes a body, it will be assumed that this body is Json 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 'lib/active_resource/base.rb', line 1222

def save
  run_callbacks :save do
    new? ? create : update
  end
end

#save! ⇒ Object

Saves the resource.

If the resource is new, it is created via POST, otherwise the existing resource is updated via PUT.

With save! validations always run. If any of them fail ActiveResource::ResourceInvalid gets raised, and nothing is POSTed to the remote system. See ActiveResource::Validations for more information.

There’s a series of callbacks associated with save!. If any of the before_* callbacks return false the action is cancelled and save! raises ActiveResource::ResourceInvalid.



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# File 'lib/active_resource/base.rb', line 1241

def save!
  save || raise(ResourceInvalid.new(self))
end

#schema ⇒ Object

If no schema has been defined for the class (see ActiveResource::schema=), the default automatic schema is generated from the current instance’s attributes



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# File 'lib/active_resource/base.rb', line 1047

def schema
  self.class.schema || self.attributes
end

#to_json(options = {}) ⇒ Object 



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# File 'lib/active_resource/base.rb', line 1410

def to_json(options={})
  super(include_root_in_json ? { :root => self.class.element_name }.merge(options) : options)
end

#to_xml(options = {}) ⇒ Object 



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# File 'lib/active_resource/base.rb', line 1414

def to_xml(options={})
  super({ :root => self.class.element_name }.merge(options))
end

#update_attribute(name, value) ⇒ Object

Updates a single attribute and then saves the object.

Note: Unlike ActiveRecord::Base.update_attribute, this method is subject to normal validation routines as an update sends the whole body of the resource in the request. (See Validations).

As such, this method is equivalent to calling update_attributes with a single attribute/value pair.

If the saving fails because of a connection or remote service error, an exception will be raised. If saving fails because the resource is invalid then false will be returned.



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# File 'lib/active_resource/base.rb', line 1370

def update_attribute(name, value)
  self.send("#{name}=".to_sym, value)
  self.save
end

#update_attributes(attributes) ⇒ Object

Updates this resource with all the attributes from the passed-in Hash and requests that the record be saved.

If the saving fails because of a connection or remote service error, an exception will be raised. If saving fails because the resource is invalid then false will be returned.

Note: Though this request can be made with a partial set of the resource’s attributes, the full body of the request will still be sent in the save request to the remote service.



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# File 'lib/active_resource/base.rb', line 1385

def update_attributes(attributes)
  load(attributes, false) && save
end