Class: ActiveResource::Base
- Inherits:
-
Object
- Object
- ActiveResource::Base
- Defined in:
- 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 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:[email protected]:3000/" end
-
defining
user
and/orpassword
variablesclass Person < ActiveResource::Base self.site = "http://api.people.com:3000/" self.user = "ryan" self.password = "password" end
For obvious security reasons, it is probably best if such services are available over HTTPS.
Note: Some values cannot be provided in the URL passed to site. e.g. email addresses as usernames. In those situations you should use the separate user and password option.
Errors & Validation
Error handling and validation is handled in much the same manner as you’re used to seeing in Active Record. Both the response code in the HTTP response and the body of the response are used to indicate that an error occurred.
Resource errors
When a GET is requested for a resource that does not exist, the HTTP 404
(Resource Not Found) response code will be returned from the server which will raise an ActiveResource::ResourceNotFound exception.
# GET http://api.people.com:3000/people/999.xml
ryan = Person.find(999) # 404, raises ActiveResource::ResourceNotFound
404
is just one of the HTTP error response codes that Active Resource will handle with its own exception. The following HTTP response codes will also result in these exceptions:
-
200..399 - Valid response, no exception (other than 301, 302)
-
301, 302 - ActiveResource::Redirection
-
400 - ActiveResource::BadRequest
-
401 - ActiveResource::UnauthorizedAccess
-
403 - ActiveResource::ForbiddenAccess
-
404 - ActiveResource::ResourceNotFound
-
405 - ActiveResource::MethodNotAllowed
-
409 - ActiveResource::ResourceConflict
-
422 - ActiveResource::ResourceInvalid (rescued by save as validation errors)
-
401..499 - ActiveResource::ClientError
-
500..599 - ActiveResource::ServerError
-
Other - ActiveResource::ConnectionError
These custom exceptions allow you to deal with resource errors more naturally and with more precision rather than returning a general HTTP error. For example:
begin
ryan = Person.find(my_id)
rescue ActiveResource::ResourceNotFound
redirect_to :action => 'not_found'
rescue ActiveResource::ResourceConflict, ActiveResource::ResourceInvalid
redirect_to :action => 'new'
end
Validation errors
Active Resource supports validations on resources and will return errors if any 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):
# <errors type="array"><error>First cannot be empty</error></errors>
#
ryan.errors.invalid?(:first) # => true
ryan.errors. # => ['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.
Instance Attribute Summary collapse
-
#attributes ⇒ Object
:nodoc:.
-
#prefix_options ⇒ Object
:nodoc:.
Class Method Summary collapse
-
.collection_path(prefix_options = {}, query_options = nil) ⇒ Object
Gets the collection path for the REST resources.
-
.connection(refresh = false) ⇒ Object
An instance of ActiveResource::Connection that is the base connection to the remote service.
-
.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:.
-
.delete(id, options = {}) ⇒ Object
Deletes the resources with the ID in the
id
parameter. -
.element_path(id, prefix_options = {}, query_options = nil) ⇒ Object
Gets the element path for the given ID in
id
. -
.exists?(id, options = {}) ⇒ Boolean
Asserts the existence of a resource, returning
true
if the resource is found. -
.find(*arguments) ⇒ Object
Core method for finding resources.
-
.format ⇒ Object
Returns the current format, default is ActiveResource::Formats::XmlFormat.
-
.format=(mime_type_reference_or_format) ⇒ Object
Sets the format that attributes are sent and received in from a mime type reference:.
- .headers ⇒ Object
-
.password ⇒ Object
Gets the password for REST HTTP authentication.
-
.password=(password) ⇒ Object
Sets the password for REST HTTP authentication.
-
.prefix(options = {}) ⇒ Object
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. -
.prefix=(value = '/') ⇒ Object
(also: set_prefix)
Sets the prefix for a resource’s nested URL (e.g.,
prefix/collectionname/1.xml
). -
.prefix_source ⇒ Object
An attribute reader for the source string for the resource path prefix.
-
.site ⇒ Object
Gets the URI of the REST resources to map for this class.
-
.site=(site) ⇒ Object
Sets the URI of the REST resources to map for this class to the value in the
site
argument. -
.timeout ⇒ Object
Gets the number of seconds after which requests to the REST API should time out.
-
.timeout=(timeout) ⇒ Object
Sets the number of seconds after which requests to the REST API should time out.
-
.user ⇒ Object
Gets the user for REST HTTP authentication.
-
.user=(user) ⇒ Object
Sets the user for REST HTTP authentication.
Instance Method Summary collapse
-
#==(other) ⇒ Object
Test for equality.
-
#clone ⇒ Object
Returns a clone of the resource that hasn’t been assigned an
id
yet and is treated as a new resource. -
#destroy ⇒ Object
Deletes the resource from the remote service.
-
#dup ⇒ Object
Duplicate the current resource without saving it.
-
#encode(options = {}) ⇒ Object
Returns the serialized string representation of the resource in the configured serialization format specified in ActiveResource::Base.format.
-
#eql?(other) ⇒ Boolean
Tests for equality (delegates to ==).
-
#exists? ⇒ Boolean
Evaluates to
true
if this resource is notnew?
and is found on the remote service. -
#hash ⇒ Object
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)].
-
#id ⇒ Object
Gets the
\id
attribute of the resource. -
#id=(id) ⇒ Object
Sets the
\id
attribute of the resource. -
#initialize(attributes = {}) ⇒ Base
constructor
Constructor method for new resources; the optional
attributes
parameter takes a hash of attributes for the new resource. -
#load(attributes) ⇒ Object
A method to manually load attributes from a hash.
-
#new? ⇒ Boolean
(also: #new_record?)
A method to determine if the resource a new object (i.e., it has not been POSTed to the remote service yet).
-
#reload ⇒ Object
A method to reload the attributes of this object from the remote web service.
-
#respond_to?(method, include_priv = false) ⇒ Boolean
A method to determine if an object responds to a message (e.g., a method call).
-
#respond_to_without_attributes? ⇒ Object
For checking
respond_to?
without searching the attributes (which is faster). -
#save ⇒ Object
A method to save (
POST
) or update (PUT
) a resource. -
#to_json(options = {}) ⇒ Object
Returns a JSON string representing the model.
-
#to_param ⇒ Object
Allows Active Resource objects to be used as parameters in Action Pack URL generation.
-
#to_xml(options = {}) ⇒ Object
A method to convert the the resource to an XML string.
Constructor Details
#initialize(attributes = {}) ⇒ 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 650 def initialize(attributes = {}) @attributes = {} @prefix_options = {} load(attributes) 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 1062 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 |
Instance Attribute Details
#attributes ⇒ Object
:nodoc:
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# File 'lib/active_resource/base.rb', line 636 def attributes @attributes end |
#prefix_options ⇒ Object
:nodoc:
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# File 'lib/active_resource/base.rb', line 637 def @prefix_options end |
Class Method Details
.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 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 'lib/active_resource/base.rb', line 431 def collection_path( = {}, = nil) , = () if .nil? "#{prefix()}#{collection_name}.#{format.extension}#{query_string()}" 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 319 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 |
.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 462 def create(attributes = {}) returning(self.new(attributes)) { |res| res.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.xml
Event.delete(params[:id]) # sends DELETE /events/5
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# File 'lib/active_resource/base.rb', line 539 def delete(id, = {}) connection.delete(element_path(id, )) 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 <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 'lib/active_resource/base.rb', line 405 def element_path(id, = {}, = nil) , = () if .nil? "#{prefix()}#{collection_name}/#{id}.#{format.extension}#{query_string()}" 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
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# File 'lib/active_resource/base.rb', line 550 def exists?(id, = {}) if id , = ([:params]) path = element_path(id, , ) response = connection.head(path, headers) response.code.to_i == 200 end # id && !find_single(id, options).nil? rescue ActiveResource::ResourceNotFound 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.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 'lib/active_resource/base.rb', line 512 def find(*arguments) scope = arguments.slice!(0) = arguments.slice!(0) || {} case scope when :all then find_every() when :first then find_every().first when :last then find_every().last when :one then find_one() else find_single(scope, ) end end |
.format ⇒ Object
Returns the current format, default is ActiveResource::Formats::XmlFormat.
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# File 'lib/active_resource/base.rb', line 297 def format read_inheritable_attribute(:format) || ActiveResource::Formats[:xml] 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 :xml
.
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# File 'lib/active_resource/base.rb', line 288 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 |
.headers ⇒ Object
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# File 'lib/active_resource/base.rb', line 331 def headers @headers ||= {} end |
.password ⇒ Object
Gets the password for REST HTTP authentication.
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# File 'lib/active_resource/base.rb', line 264 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 274 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.xml
) 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 344 def prefix(={}) default = site.path default << '/' unless default[-1..-1] == '/' # generate the actual method based on the current site path self.prefix = default prefix() end |
.prefix=(value = '/') ⇒ Object Also known as: set_prefix
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 'lib/active_resource/base.rb', line 361 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 |
.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 354 def prefix_source prefix # generate #prefix and #prefix_source methods first prefix_source 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 211 def site # Not using superclass_delegating_reader because don't want subclasses to modify superclass instance # # With superclass_delegating_reader # # Parent.site = 'http://[email protected]' # Subclass.site # => 'http://[email protected]' # Subclass.site.user = 'david' # Parent.site # => 'http://[email protected]' # # Without superclass_delegating_reader (expected behaviour) # # Parent.site = 'http://[email protected]' # Subclass.site # => 'http://[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 236 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 |
.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 308 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 302 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 248 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 258 def user=(user) @connection = nil @user = user 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 746 def ==(other) other.equal?(self) || (other.instance_of?(self.class) && !other.new? && other.id == id) 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 676 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. = self. 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 809 def destroy connection.delete(element_path, self.class.headers) end |
#dup ⇒ Object
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 'lib/active_resource/base.rb', line 773 def dup returning self.class.new do |resource| resource.attributes = @attributes resource. = @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 894 def encode(={}) case self.class.format when ActiveResource::Formats[:xml] self.class.format.encode(attributes, {:root => self.class.element_name}.merge()) else self.class.format.encode(attributes, ) end end |
#eql?(other) ⇒ Boolean
Tests for equality (delegates to ==).
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# File 'lib/active_resource/base.rb', line 751 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
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# File 'lib/active_resource/base.rb', line 829 def exists? !new? && self.class.exists?(to_param, :params => ) end |
#hash ⇒ Object
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 'lib/active_resource/base.rb', line 757 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 710 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 715 def id=(id) attributes[self.class.primary_key] = id end |
#load(attributes) ⇒ 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
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# File 'lib/active_resource/base.rb', line 939 def load(attributes) raise ArgumentError, "expected an attributes Hash, got #{attributes.inspect}" unless attributes.is_a?(Hash) @prefix_options, attributes = (attributes) attributes.each do |key, value| @attributes[key.to_s] = case value when Array resource = find_or_create_resource_for_collection(key) value.map { |attrs| attrs.is_a?(String) ? attrs.dup : resource.new(attrs) } when Hash resource = find_or_create_resource_for(key) resource.new(value) else value.dup rescue value end end self end |
#new? ⇒ Boolean Also known as: new_record?
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 'lib/active_resource/base.rb', line 704 def new? id.nil? 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 914 def reload self.load(self.class.find(to_param, :params => @prefix_options).attributes) 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?)
.
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# File 'lib/active_resource/base.rb', line 964 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 |
#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 959 alias_method :respond_to_without_attributes?, :respond_to? |
#save ⇒ Object
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 'lib/active_resource/base.rb', line 793 def save new? ? create : update end |
#to_json(options = {}) ⇒ Object
Returns a JSON string representing the model. Some configuration is available through options
.
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 'lib/active_resource/base.rb', line 887 def to_json(={}) attributes.to_json() end |
#to_param ⇒ Object
Allows Active Resource objects to be used as parameters in Action Pack URL generation.
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# File 'lib/active_resource/base.rb', line 720 def to_param id && id.to_s end |
#to_xml(options = {}) ⇒ Object
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 is2
). -
:dasherize
- Boolean option to determine whether or not element names should replace underscores with dashes (default isfalse
). -
:skip_instruct
- Toggle skipping theinstruct!
call on the XML builder that generates the XML declaration (default isfalse
).
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 'lib/active_resource/base.rb', line 858 def to_xml(={}) attributes.to_xml({:root => self.class.element_name}.merge()) end |