1015 lines
38 KiB
Ruby
1015 lines
38 KiB
Ruby
require 'active_resource/connection'
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require 'cgi'
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require 'set'
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module ActiveResource
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# ActiveResource::Base is the main class for mapping RESTful resources as models in a Rails application.
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#
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# For an outline of what Active Resource is capable of, see link:files/vendor/rails/activeresource/README.html.
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#
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# == Automated mapping
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#
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# Active Resource objects represent your RESTful resources as manipulatable Ruby objects. To map resources
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# to Ruby objects, Active Resource only needs a class name that corresponds to the resource name (e.g., the class
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# Person maps to the resources people, very similarly to Active Record) and a +site+ value, which holds the
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# URI of the resources.
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#
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# class Person < ActiveResource::Base
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# self.site = "http://api.people.com:3000/"
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# end
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#
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# Now the Person class is mapped to RESTful resources located at <tt>http://api.people.com:3000/people/</tt>, and
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# you can now use Active Resource's lifecycles methods to manipulate resources. In the case where you already have
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# an existing model with the same name as the desired RESTful resource you can set the +element_name+ value.
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#
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# class PersonResource < ActiveResource::Base
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# self.site = "http://api.people.com:3000/"
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# self.element_name = "person"
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# end
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#
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#
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# == Lifecycle methods
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#
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# Active Resource exposes methods for creating, finding, updating, and deleting resources
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# from REST web services.
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#
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# ryan = Person.new(:first => 'Ryan', :last => 'Daigle')
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# ryan.save #=> true
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# ryan.id #=> 2
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# Person.exists?(ryan.id) #=> true
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# ryan.exists? #=> true
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#
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# ryan = Person.find(1)
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# # => Resource holding our newly created Person object
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#
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# ryan.first = 'Rizzle'
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# ryan.save #=> true
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#
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# ryan.destroy #=> true
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#
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# As you can see, these are very similar to Active Record's lifecycle methods for database records.
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# You can read more about each of these methods in their respective documentation.
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#
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# === Custom REST methods
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#
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# Since simple CRUD/lifecycle methods can't accomplish every task, Active Resource also supports
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# defining your own custom REST methods. To invoke them, Active Resource provides the <tt>get</tt>,
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# <tt>post</tt>, <tt>put</tt> and <tt>delete</tt> methods where you can specify a custom REST method
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# name to invoke.
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#
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# # POST to the custom 'register' REST method, i.e. POST /people/new/register.xml.
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# Person.new(:name => 'Ryan').post(:register)
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# # => { :id => 1, :name => 'Ryan', :position => 'Clerk' }
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#
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# # PUT an update by invoking the 'promote' REST method, i.e. PUT /people/1/promote.xml?position=Manager.
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# Person.find(1).put(:promote, :position => 'Manager')
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# # => { :id => 1, :name => 'Ryan', :position => 'Manager' }
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#
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# # GET all the positions available, i.e. GET /people/positions.xml.
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# Person.get(:positions)
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# # => [{:name => 'Manager'}, {:name => 'Clerk'}]
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#
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# # DELETE to 'fire' a person, i.e. DELETE /people/1/fire.xml.
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# Person.find(1).delete(:fire)
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#
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# For more information on using custom REST methods, see the
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# ActiveResource::CustomMethods documentation.
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#
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# == Validations
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#
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# You can validate resources client side by overriding validation methods in the base class.
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#
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# class Person < ActiveResource::Base
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# self.site = "http://api.people.com:3000/"
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# protected
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# def validate
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# errors.add("last", "has invalid characters") unless last =~ /[a-zA-Z]*/
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# end
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# end
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#
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# See the ActiveResource::Validations documentation for more information.
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#
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# == Authentication
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#
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# Many REST APIs will require authentication, usually in the form of basic
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# HTTP authentication. Authentication can be specified by:
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# * putting the credentials in the URL for the +site+ variable.
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#
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# class Person < ActiveResource::Base
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# self.site = "http://ryan:password@api.people.com:3000/"
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# end
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#
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# * defining +user+ and/or +password+ variables
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#
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# class Person < ActiveResource::Base
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# self.site = "http://api.people.com:3000/"
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# self.user = "ryan"
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# self.password = "password"
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# end
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#
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# For obvious security reasons, it is probably best if such services are available
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# over HTTPS.
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#
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# Note: Some values cannot be provided in the URL passed to site. e.g. email addresses
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# as usernames. In those situations you should use the seperate user and password option.
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# == Errors & Validation
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#
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# Error handling and validation is handled in much the same manner as you're used to seeing in
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# Active Record. Both the response code in the HTTP response and the body of the response are used to
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# indicate that an error occurred.
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#
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# === Resource errors
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#
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# When a GET is requested for a resource that does not exist, the HTTP <tt>404</tt> (Resource Not Found)
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# response code will be returned from the server which will raise an ActiveResource::ResourceNotFound
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# exception.
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#
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# # GET http://api.people.com:3000/people/999.xml
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# ryan = Person.find(999) # 404, raises ActiveResource::ResourceNotFound
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#
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# <tt>404</tt> is just one of the HTTP error response codes that ActiveResource will handle with its own exception. The
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# following HTTP response codes will also result in these exceptions:
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#
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# * 200..399 - Valid response, no exception
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# * 404 - ActiveResource::ResourceNotFound
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# * 409 - ActiveResource::ResourceConflict
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# * 422 - ActiveResource::ResourceInvalid (rescued by save as validation errors)
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# * 401..499 - ActiveResource::ClientError
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# * 500..599 - ActiveResource::ServerError
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#
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# These custom exceptions allow you to deal with resource errors more naturally and with more precision
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# rather than returning a general HTTP error. For example:
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#
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# begin
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# ryan = Person.find(my_id)
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# rescue ActiveResource::ResourceNotFound
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# redirect_to :action => 'not_found'
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# rescue ActiveResource::ResourceConflict, ActiveResource::ResourceInvalid
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# redirect_to :action => 'new'
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# end
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#
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# === Validation errors
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#
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# Active Resource supports validations on resources and will return errors if any these validations fail
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# (e.g., "First name can not be blank" and so on). These types of errors are denoted in the response by
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# a response code of <tt>422</tt> and an XML representation of the validation errors. The save operation will
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# then fail (with a <tt>false</tt> return value) and the validation errors can be accessed on the resource in question.
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#
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# ryan = Person.find(1)
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# ryan.first #=> ''
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# ryan.save #=> false
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#
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# # When
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# # PUT http://api.people.com:3000/people/1.xml
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# # is requested with invalid values, the response is:
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# #
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# # Response (422):
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# # <errors type="array"><error>First cannot be empty</error></errors>
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# #
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#
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# ryan.errors.invalid?(:first) #=> true
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# ryan.errors.full_messages #=> ['First cannot be empty']
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#
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# Learn more about Active Resource's validation features in the ActiveResource::Validations documentation.
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#
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# === Timeouts
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#
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# Active Resource relies on HTTP to access RESTful APIs and as such is inherently susceptible to slow or
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# unresponsive servers. In such cases, your Active Resource method calls could timeout. You can control the
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# amount of time before Active Resource times out with the +timeout+ variable.
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#
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# class Person < ActiveResource::Base
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# self.site = "http://api.people.com:3000/"
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# self.timeout = 5
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# end
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#
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# This sets the +timeout+ to 5 seconds. You can adjust the +timeout+ to a value suitable for the RESTful API
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# you are accessing. It is recommended to set this to a reasonably low value to allow your Active Resource
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# clients (especially if you are using Active Resource in a Rails application) to fail-fast (see
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# http://en.wikipedia.org/wiki/Fail-fast) rather than cause cascading failures that could incapacitate your
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# server.
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#
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# When a timeout occurs, an ActiveResource::TimeoutError is raised. You should rescue from
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# ActiveResource::TimeoutError in your Active Resource method calls.
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#
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# Internally, Active Resource relies on Ruby's Net::HTTP library to make HTTP requests. Setting +timeout+
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# sets the <tt>read_timeout</tt> of the internal Net::HTTP instance to the same value. The default
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# <tt>read_timeout</tt> is 60 seconds on most Ruby implementations.
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class Base
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# The logger for diagnosing and tracing Active Resource calls.
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cattr_accessor :logger
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class << self
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# Gets the URI of the REST resources to map for this class. The site variable is required
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# ActiveResource's mapping to work.
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def site
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# Not using superclass_delegating_reader because don't want subclasses to modify superclass instance
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#
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# With superclass_delegating_reader
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#
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# Parent.site = 'http://anonymous@test.com'
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# Subclass.site # => 'http://anonymous@test.com'
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# Subclass.site.user = 'david'
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# Parent.site # => 'http://david@test.com'
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#
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# Without superclass_delegating_reader (expected behaviour)
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#
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# Parent.site = 'http://anonymous@test.com'
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# Subclass.site # => 'http://anonymous@test.com'
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# Subclass.site.user = 'david' # => TypeError: can't modify frozen object
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#
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if defined?(@site)
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@site
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elsif superclass != Object && superclass.site
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superclass.site.dup.freeze
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end
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end
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# Sets the URI of the REST resources to map for this class to the value in the +site+ argument.
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# The site variable is required ActiveResource's mapping to work.
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def site=(site)
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@connection = nil
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if site.nil?
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@site = nil
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else
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@site = create_site_uri_from(site)
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@user = URI.decode(@site.user) if @site.user
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@password = URI.decode(@site.password) if @site.password
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end
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end
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# Gets the user for REST HTTP authentication.
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def user
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# Not using superclass_delegating_reader. See +site+ for explanation
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if defined?(@user)
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@user
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elsif superclass != Object && superclass.user
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superclass.user.dup.freeze
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end
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end
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# Sets the user for REST HTTP authentication.
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def user=(user)
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@connection = nil
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@user = user
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end
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# Gets the password for REST HTTP authentication.
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def password
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# Not using superclass_delegating_reader. See +site+ for explanation
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if defined?(@password)
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@password
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elsif superclass != Object && superclass.password
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superclass.password.dup.freeze
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end
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end
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# Sets the password for REST HTTP authentication.
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def password=(password)
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@connection = nil
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@password = password
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end
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# Sets the format that attributes are sent and received in from a mime type reference:
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#
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# Person.format = :json
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# Person.find(1) # => GET /people/1.json
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#
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# Person.format = ActiveResource::Formats::XmlFormat
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# Person.find(1) # => GET /people/1.xml
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#
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# Default format is <tt>:xml</tt>.
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def format=(mime_type_reference_or_format)
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format = mime_type_reference_or_format.is_a?(Symbol) ?
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ActiveResource::Formats[mime_type_reference_or_format] : mime_type_reference_or_format
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write_inheritable_attribute("format", format)
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connection.format = format if site
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end
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# Returns the current format, default is ActiveResource::Formats::XmlFormat.
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def format # :nodoc:
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read_inheritable_attribute("format") || ActiveResource::Formats[:xml]
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end
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# Sets the number of seconds after which requests to the REST API should time out.
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def timeout=(timeout)
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@connection = nil
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@timeout = timeout
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end
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# Gets tthe number of seconds after which requests to the REST API should time out.
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def timeout
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if defined?(@timeout)
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@timeout
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elsif superclass != Object && superclass.timeout
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superclass.timeout
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end
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end
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# An instance of ActiveResource::Connection that is the base connection to the remote service.
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# The +refresh+ parameter toggles whether or not the connection is refreshed at every request
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# or not (defaults to <tt>false</tt>).
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def connection(refresh = false)
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if defined?(@connection) || superclass == Object
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@connection = Connection.new(site, format) if refresh || @connection.nil?
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@connection.user = user if user
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@connection.password = password if password
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@connection.timeout = timeout if timeout
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@connection
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else
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superclass.connection
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end
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end
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def headers
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@headers ||= {}
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end
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# Do not include any modules in the default element name. This makes it easier to seclude ARes objects
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# in a separate namespace without having to set element_name repeatedly.
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attr_accessor_with_default(:element_name) { to_s.split("::").last.underscore } #:nodoc:
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attr_accessor_with_default(:collection_name) { element_name.pluralize } #:nodoc:
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attr_accessor_with_default(:primary_key, 'id') #:nodoc:
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# Gets the prefix for a resource's nested URL (e.g., <tt>prefix/collectionname/1.xml</tt>)
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# This method is regenerated at runtime based on what the prefix is set to.
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def prefix(options={})
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default = site.path
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default << '/' unless default[-1..-1] == '/'
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# generate the actual method based on the current site path
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self.prefix = default
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prefix(options)
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end
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# An attribute reader for the source string for the resource path prefix. This
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# method is regenerated at runtime based on what the prefix is set to.
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def prefix_source
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prefix # generate #prefix and #prefix_source methods first
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prefix_source
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end
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# Sets the prefix for a resource's nested URL (e.g., <tt>prefix/collectionname/1.xml</tt>).
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# Default value is <tt>site.path</tt>.
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def prefix=(value = '/')
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# Replace :placeholders with '#{embedded options[:lookups]}'
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prefix_call = value.gsub(/:\w+/) { |key| "\#{options[#{key}]}" }
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# Redefine the new methods.
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code = <<-end_code
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def prefix_source() "#{value}" end
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def prefix(options={}) "#{prefix_call}" end
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end_code
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silence_warnings { instance_eval code, __FILE__, __LINE__ }
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rescue
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logger.error "Couldn't set prefix: #{$!}\n #{code}"
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raise
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end
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alias_method :set_prefix, :prefix= #:nodoc:
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alias_method :set_element_name, :element_name= #:nodoc:
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alias_method :set_collection_name, :collection_name= #:nodoc:
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# Gets the element path for the given ID in +id+. If the +query_options+ parameter is omitted, Rails
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# will split from the prefix options.
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#
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# ==== Options
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# +prefix_options+ - A hash to add a prefix to the request for nested URLs (e.g., <tt>:account_id => 19</tt>
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# would yield a URL like <tt>/accounts/19/purchases.xml</tt>).
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# +query_options+ - A hash to add items to the query string for the request.
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#
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# ==== Examples
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# Post.element_path(1)
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# # => /posts/1.xml
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#
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# Comment.element_path(1, :post_id => 5)
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# # => /posts/5/comments/1.xml
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#
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# Comment.element_path(1, :post_id => 5, :active => 1)
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# # => /posts/5/comments/1.xml?active=1
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#
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# Comment.element_path(1, {:post_id => 5}, {:active => 1})
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# # => /posts/5/comments/1.xml?active=1
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#
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def element_path(id, prefix_options = {}, query_options = nil)
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prefix_options, query_options = split_options(prefix_options) if query_options.nil?
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"#{prefix(prefix_options)}#{collection_name}/#{id}.#{format.extension}#{query_string(query_options)}"
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end
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# Gets the collection path for the REST resources. If the +query_options+ parameter is omitted, Rails
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# will split from the +prefix_options+.
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#
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# ==== Options
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# * +prefix_options+ - A hash to add a prefix to the request for nested URL's (e.g., <tt>:account_id => 19</tt>
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# would yield a URL like <tt>/accounts/19/purchases.xml</tt>).
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# * +query_options+ - A hash to add items to the query string for the request.
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#
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# ==== Examples
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# Post.collection_path
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# # => /posts.xml
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#
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# Comment.collection_path(:post_id => 5)
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# # => /posts/5/comments.xml
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#
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# Comment.collection_path(:post_id => 5, :active => 1)
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# # => /posts/5/comments.xml?active=1
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#
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# Comment.collection_path({:post_id => 5}, {:active => 1})
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# # => /posts/5/comments.xml?active=1
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#
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def collection_path(prefix_options = {}, query_options = nil)
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prefix_options, query_options = split_options(prefix_options) if query_options.nil?
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"#{prefix(prefix_options)}#{collection_name}.#{format.extension}#{query_string(query_options)}"
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end
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alias_method :set_primary_key, :primary_key= #:nodoc:
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# Create a new resource instance and request to the remote service
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# that it be saved, making it equivalent to the following simultaneous calls:
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#
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# ryan = Person.new(:first => 'ryan')
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# ryan.save
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#
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# The newly created resource is returned. If a failure has occurred an
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# exception will be raised (see save). If the resource is invalid and
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# has not been saved then valid? will return <tt>false</tt>,
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# while new? will still return <tt>true</tt>.
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#
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# ==== Examples
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# Person.create(:name => 'Jeremy', :email => 'myname@nospam.com', :enabled => true)
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# my_person = Person.find(:first)
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# my_person.email # => myname@nospam.com
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#
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# dhh = Person.create(:name => 'David', :email => 'dhh@nospam.com', :enabled => true)
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# dhh.valid? # => true
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# dhh.new? # => false
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#
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# # We'll assume that there's a validation that requires the name attribute
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# that_guy = Person.create(:name => '', :email => 'thatguy@nospam.com', :enabled => true)
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# that_guy.valid? # => false
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# that_guy.new? # => true
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def create(attributes = {})
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returning(self.new(attributes)) { |res| res.save }
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end
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# Core method for finding resources. Used similarly to Active Record's +find+ method.
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#
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# ==== Arguments
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|
# The first argument is considered to be the scope of the query. That is, how many
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# resources are returned from the request. It can be one of the following.
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#
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# * <tt>:one</tt> - Returns a single resource.
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# * <tt>:first</tt> - Returns the first resource found.
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# * <tt>:all</tt> - Returns every resource that matches the request.
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#
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# ==== Options
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|
#
|
|
# * <tt>:from</tt> - Sets the path or custom method that resources will be fetched from.
|
|
# * <tt>:params</tt> - Sets query and prefix (nested URL) parameters.
|
|
#
|
|
# ==== Examples
|
|
# Person.find(1)
|
|
# # => GET /people/1.xml
|
|
#
|
|
# Person.find(:all)
|
|
# # => GET /people.xml
|
|
#
|
|
# Person.find(:all, :params => { :title => "CEO" })
|
|
# # => GET /people.xml?title=CEO
|
|
#
|
|
# Person.find(:first, :from => :managers)
|
|
# # => GET /people/managers.xml
|
|
#
|
|
# Person.find(:all, :from => "/companies/1/people.xml")
|
|
# # => GET /companies/1/people.xml
|
|
#
|
|
# Person.find(:one, :from => :leader)
|
|
# # => GET /people/leader.xml
|
|
#
|
|
# Person.find(:all, :from => :developers, :params => { :language => 'ruby' })
|
|
# # => GET /people/developers.xml?language=ruby
|
|
#
|
|
# Person.find(:one, :from => "/companies/1/manager.xml")
|
|
# # => GET /companies/1/manager.xml
|
|
#
|
|
# StreetAddress.find(1, :params => { :person_id => 1 })
|
|
# # => GET /people/1/street_addresses/1.xml
|
|
def find(*arguments)
|
|
scope = arguments.slice!(0)
|
|
options = arguments.slice!(0) || {}
|
|
|
|
case scope
|
|
when :all then find_every(options)
|
|
when :first then find_every(options).first
|
|
when :one then find_one(options)
|
|
else find_single(scope, options)
|
|
end
|
|
end
|
|
|
|
# Deletes the resources with the ID in the +id+ parameter.
|
|
#
|
|
# ==== Options
|
|
# All options specify prefix and query parameters.
|
|
#
|
|
# ==== Examples
|
|
# Event.delete(2) # sends DELETE /events/2
|
|
#
|
|
# Event.create(:name => 'Free Concert', :location => 'Community Center')
|
|
# my_event = Event.find(:first) # let's assume this is event with ID 7
|
|
# Event.delete(my_event.id) # sends DELETE /events/7
|
|
#
|
|
# # Let's assume a request to events/5/cancel.xml
|
|
# Event.delete(params[:id]) # sends DELETE /events/5
|
|
def delete(id, options = {})
|
|
connection.delete(element_path(id, options))
|
|
end
|
|
|
|
# Asserts the existence of a resource, returning <tt>true</tt> if the resource is found.
|
|
#
|
|
# ==== Examples
|
|
# Note.create(:title => 'Hello, world.', :body => 'Nothing more for now...')
|
|
# Note.exists?(1) # => true
|
|
#
|
|
# Note.exists(1349) # => false
|
|
def exists?(id, options = {})
|
|
if id
|
|
prefix_options, query_options = split_options(options[:params])
|
|
path = element_path(id, prefix_options, query_options)
|
|
response = connection.head(path, headers)
|
|
response.code == 200
|
|
end
|
|
# id && !find_single(id, options).nil?
|
|
rescue ActiveResource::ResourceNotFound
|
|
false
|
|
end
|
|
|
|
private
|
|
# Find every resource
|
|
def find_every(options)
|
|
case from = options[:from]
|
|
when Symbol
|
|
instantiate_collection(get(from, options[:params]))
|
|
when String
|
|
path = "#{from}#{query_string(options[:params])}"
|
|
instantiate_collection(connection.get(path, headers) || [])
|
|
else
|
|
prefix_options, query_options = split_options(options[:params])
|
|
path = collection_path(prefix_options, query_options)
|
|
instantiate_collection( (connection.get(path, headers) || []), prefix_options )
|
|
end
|
|
end
|
|
|
|
# Find a single resource from a one-off URL
|
|
def find_one(options)
|
|
case from = options[:from]
|
|
when Symbol
|
|
instantiate_record(get(from, options[:params]))
|
|
when String
|
|
path = "#{from}#{query_string(options[:params])}"
|
|
instantiate_record(connection.get(path, headers))
|
|
end
|
|
end
|
|
|
|
# Find a single resource from the default URL
|
|
def find_single(scope, options)
|
|
prefix_options, query_options = split_options(options[:params])
|
|
path = element_path(scope, prefix_options, query_options)
|
|
instantiate_record(connection.get(path, headers), prefix_options)
|
|
end
|
|
|
|
def instantiate_collection(collection, prefix_options = {})
|
|
collection.collect! { |record| instantiate_record(record, prefix_options) }
|
|
end
|
|
|
|
def instantiate_record(record, prefix_options = {})
|
|
returning new(record) do |resource|
|
|
resource.prefix_options = prefix_options
|
|
end
|
|
end
|
|
|
|
|
|
# Accepts a URI and creates the site URI from that.
|
|
def create_site_uri_from(site)
|
|
site.is_a?(URI) ? site.dup : URI.parse(site)
|
|
end
|
|
|
|
# contains a set of the current prefix parameters.
|
|
def prefix_parameters
|
|
@prefix_parameters ||= prefix_source.scan(/:\w+/).map { |key| key[1..-1].to_sym }.to_set
|
|
end
|
|
|
|
# Builds the query string for the request.
|
|
def query_string(options)
|
|
"?#{options.to_query}" unless options.nil? || options.empty?
|
|
end
|
|
|
|
# split an option hash into two hashes, one containing the prefix options,
|
|
# and the other containing the leftovers.
|
|
def split_options(options = {})
|
|
prefix_options, query_options = {}, {}
|
|
|
|
(options || {}).each do |key, value|
|
|
next if key.blank?
|
|
(prefix_parameters.include?(key.to_sym) ? prefix_options : query_options)[key.to_sym] = value
|
|
end
|
|
|
|
[ prefix_options, query_options ]
|
|
end
|
|
end
|
|
|
|
attr_accessor :attributes #:nodoc:
|
|
attr_accessor :prefix_options #:nodoc:
|
|
|
|
# Constructor method for new resources; the optional +attributes+ parameter takes a hash
|
|
# of attributes for the new resource.
|
|
#
|
|
# ==== Examples
|
|
# my_course = Course.new
|
|
# my_course.name = "Western Civilization"
|
|
# my_course.lecturer = "Don Trotter"
|
|
# my_course.save
|
|
#
|
|
# my_other_course = Course.new(:name => "Philosophy: Reason and Being", :lecturer => "Ralph Cling")
|
|
# my_other_course.save
|
|
def initialize(attributes = {})
|
|
@attributes = {}
|
|
@prefix_options = {}
|
|
load(attributes)
|
|
end
|
|
|
|
# Returns a clone of the resource that hasn't been assigned an +id+ yet and
|
|
# is treated as a new resource.
|
|
#
|
|
# ryan = Person.find(1)
|
|
# not_ryan = ryan.clone
|
|
# not_ryan.new? # => true
|
|
#
|
|
# Any active resource member attributes will NOT be cloned, though all other
|
|
# attributes are. This is to prevent the conflict between any +prefix_options+
|
|
# that refer to the original parent resource and the newly cloned parent
|
|
# resource that does not exist.
|
|
#
|
|
# ryan = Person.find(1)
|
|
# ryan.address = StreetAddress.find(1, :person_id => ryan.id)
|
|
# ryan.hash = {:not => "an ARes instance"}
|
|
#
|
|
# not_ryan = ryan.clone
|
|
# not_ryan.new? # => true
|
|
# not_ryan.address # => NoMethodError
|
|
# not_ryan.hash # => {:not => "an ARes instance"}
|
|
def clone
|
|
# Clone all attributes except the pk and any nested ARes
|
|
cloned = attributes.reject {|k,v| k == self.class.primary_key || v.is_a?(ActiveResource::Base)}.inject({}) do |attrs, (k, v)|
|
|
attrs[k] = v.clone
|
|
attrs
|
|
end
|
|
# Form the new resource - bypass initialize of resource with 'new' as that will call 'load' which
|
|
# attempts to convert hashes into member objects and arrays into collections of objects. We want
|
|
# the raw objects to be cloned so we bypass load by directly setting the attributes hash.
|
|
resource = self.class.new({})
|
|
resource.prefix_options = self.prefix_options
|
|
resource.send :instance_variable_set, '@attributes', cloned
|
|
resource
|
|
end
|
|
|
|
|
|
# A method to determine if the resource a new object (i.e., it has not been POSTed to the remote service yet).
|
|
#
|
|
# ==== Examples
|
|
# not_new = Computer.create(:brand => 'Apple', :make => 'MacBook', :vendor => 'MacMall')
|
|
# not_new.new? # => false
|
|
#
|
|
# is_new = Computer.new(:brand => 'IBM', :make => 'Thinkpad', :vendor => 'IBM')
|
|
# is_new.new? # => true
|
|
#
|
|
# is_new.save
|
|
# is_new.new? # => false
|
|
#
|
|
def new?
|
|
id.nil?
|
|
end
|
|
|
|
# Get the +id+ attribute of the resource.
|
|
def id
|
|
attributes[self.class.primary_key]
|
|
end
|
|
|
|
# Set the +id+ attribute of the resource.
|
|
def id=(id)
|
|
attributes[self.class.primary_key] = id
|
|
end
|
|
|
|
# Allows ActiveResource objects to be used as parameters in ActionPack URL generation.
|
|
def to_param
|
|
id && id.to_s
|
|
end
|
|
|
|
# Test for equality. Resource are equal if and only if +other+ is the same object or
|
|
# is an instance of the same class, is not <tt>new?</tt>, and has the same +id+.
|
|
#
|
|
# ==== Examples
|
|
# ryan = Person.create(:name => 'Ryan')
|
|
# jamie = Person.create(:name => 'Jamie')
|
|
#
|
|
# ryan == jamie
|
|
# # => false (Different name attribute and id)
|
|
#
|
|
# ryan_again = Person.new(:name => 'Ryan')
|
|
# ryan == ryan_again
|
|
# # => false (ryan_again is new?)
|
|
#
|
|
# ryans_clone = Person.create(:name => 'Ryan')
|
|
# ryan == ryans_clone
|
|
# # => false (Different id attributes)
|
|
#
|
|
# ryans_twin = Person.find(ryan.id)
|
|
# ryan == ryans_twin
|
|
# # => true
|
|
#
|
|
def ==(other)
|
|
other.equal?(self) || (other.instance_of?(self.class) && !other.new? && other.id == id)
|
|
end
|
|
|
|
# Tests for equality (delegates to ==).
|
|
def eql?(other)
|
|
self == other
|
|
end
|
|
|
|
# Delegates to id in order to allow two resources of the same type and id to work with something like:
|
|
# [Person.find(1), Person.find(2)] & [Person.find(1), Person.find(4)] # => [Person.find(1)]
|
|
def hash
|
|
id.hash
|
|
end
|
|
|
|
# Duplicate the current resource without saving it.
|
|
#
|
|
# ==== Examples
|
|
# my_invoice = Invoice.create(:customer => 'That Company')
|
|
# next_invoice = my_invoice.dup
|
|
# next_invoice.new? # => true
|
|
#
|
|
# next_invoice.save
|
|
# next_invoice == my_invoice # => false (different id attributes)
|
|
#
|
|
# my_invoice.customer # => That Company
|
|
# next_invoice.customer # => That Company
|
|
def dup
|
|
returning self.class.new do |resource|
|
|
resource.attributes = @attributes
|
|
resource.prefix_options = @prefix_options
|
|
end
|
|
end
|
|
|
|
# A method to save (+POST+) or update (+PUT+) a resource. It delegates to +create+ if a new object,
|
|
# +update+ if it is existing. If the response to the save includes a body, it will be assumed that this body
|
|
# is XML for the final object as it looked after the save (which would include attributes like +created_at+
|
|
# that weren't part of the original submit).
|
|
#
|
|
# ==== Examples
|
|
# my_company = Company.new(:name => 'RoleModel Software', :owner => 'Ken Auer', :size => 2)
|
|
# my_company.new? # => true
|
|
# my_company.save # sends POST /companies/ (create)
|
|
#
|
|
# my_company.new? # => false
|
|
# my_company.size = 10
|
|
# my_company.save # sends PUT /companies/1 (update)
|
|
def save
|
|
new? ? create : update
|
|
end
|
|
|
|
# Deletes the resource from the remote service.
|
|
#
|
|
# ==== Examples
|
|
# my_id = 3
|
|
# my_person = Person.find(my_id)
|
|
# my_person.destroy
|
|
# Person.find(my_id) # 404 (Resource Not Found)
|
|
#
|
|
# new_person = Person.create(:name => 'James')
|
|
# new_id = new_person.id # => 7
|
|
# new_person.destroy
|
|
# Person.find(new_id) # 404 (Resource Not Found)
|
|
def destroy
|
|
connection.delete(element_path, self.class.headers)
|
|
end
|
|
|
|
# Evaluates to <tt>true</tt> if this resource is not <tt>new?</tt> and is
|
|
# found on the remote service. Using this method, you can check for
|
|
# resources that may have been deleted between the object's instantiation
|
|
# and actions on it.
|
|
#
|
|
# ==== Examples
|
|
# Person.create(:name => 'Theodore Roosevelt')
|
|
# that_guy = Person.find(:first)
|
|
# that_guy.exists? # => true
|
|
#
|
|
# that_lady = Person.new(:name => 'Paul Bean')
|
|
# that_lady.exists? # => false
|
|
#
|
|
# guys_id = that_guy.id
|
|
# Person.delete(guys_id)
|
|
# that_guy.exists? # => false
|
|
def exists?
|
|
!new? && self.class.exists?(to_param, :params => prefix_options)
|
|
end
|
|
|
|
# A method to convert the the resource to an XML string.
|
|
#
|
|
# ==== Options
|
|
# The +options+ parameter is handed off to the +to_xml+ method on each
|
|
# attribute, so it has the same options as the +to_xml+ methods in
|
|
# ActiveSupport.
|
|
#
|
|
# * <tt>:indent</tt> - Set the indent level for the XML output (default is +2+).
|
|
# * <tt>:dasherize</tt> - Boolean option to determine whether or not element names should
|
|
# replace underscores with dashes (default is <tt>false</tt>).
|
|
# * <tt>:skip_instruct</tt> - Toggle skipping the +instruct!+ call on the XML builder
|
|
# that generates the XML declaration (default is <tt>false</tt>).
|
|
#
|
|
# ==== Examples
|
|
# my_group = SubsidiaryGroup.find(:first)
|
|
# my_group.to_xml
|
|
# # => <?xml version="1.0" encoding="UTF-8"?>
|
|
# # <subsidiary_group> [...] </subsidiary_group>
|
|
#
|
|
# my_group.to_xml(:dasherize => true)
|
|
# # => <?xml version="1.0" encoding="UTF-8"?>
|
|
# # <subsidiary-group> [...] </subsidiary-group>
|
|
#
|
|
# my_group.to_xml(:skip_instruct => true)
|
|
# # => <subsidiary_group> [...] </subsidiary_group>
|
|
def to_xml(options={})
|
|
attributes.to_xml({:root => self.class.element_name}.merge(options))
|
|
end
|
|
|
|
# A method to reload the attributes of this object from the remote web service.
|
|
#
|
|
# ==== Examples
|
|
# my_branch = Branch.find(:first)
|
|
# my_branch.name # => "Wislon Raod"
|
|
#
|
|
# # Another client fixes the typo...
|
|
#
|
|
# my_branch.name # => "Wislon Raod"
|
|
# my_branch.reload
|
|
# my_branch.name # => "Wilson Road"
|
|
def reload
|
|
self.load(self.class.find(to_param, :params => @prefix_options).attributes)
|
|
end
|
|
|
|
# A method to manually load attributes from a hash. Recursively loads collections of
|
|
# resources. This method is called in +initialize+ and +create+ when a hash of attributes
|
|
# is provided.
|
|
#
|
|
# ==== Examples
|
|
# my_attrs = {:name => 'J&J Textiles', :industry => 'Cloth and textiles'}
|
|
#
|
|
# the_supplier = Supplier.find(:first)
|
|
# the_supplier.name # => 'J&M Textiles'
|
|
# the_supplier.load(my_attrs)
|
|
# the_supplier.name('J&J Textiles')
|
|
#
|
|
# # These two calls are the same as Supplier.new(my_attrs)
|
|
# my_supplier = Supplier.new
|
|
# my_supplier.load(my_attrs)
|
|
#
|
|
# # These three calls are the same as Supplier.create(my_attrs)
|
|
# your_supplier = Supplier.new
|
|
# your_supplier.load(my_attrs)
|
|
# your_supplier.save
|
|
def load(attributes)
|
|
raise ArgumentError, "expected an attributes Hash, got #{attributes.inspect}" unless attributes.is_a?(Hash)
|
|
@prefix_options, attributes = split_options(attributes)
|
|
attributes.each do |key, value|
|
|
@attributes[key.to_s] =
|
|
case value
|
|
when Array
|
|
resource = find_or_create_resource_for_collection(key)
|
|
value.map { |attrs| resource.new(attrs) }
|
|
when Hash
|
|
resource = find_or_create_resource_for(key)
|
|
resource.new(value)
|
|
else
|
|
value.dup rescue value
|
|
end
|
|
end
|
|
self
|
|
end
|
|
|
|
# For checking <tt>respond_to?</tt> without searching the attributes (which is faster).
|
|
alias_method :respond_to_without_attributes?, :respond_to?
|
|
|
|
# A method to determine if an object responds to a message (e.g., a method call). In Active Resource, a Person object with a
|
|
# +name+ attribute can answer <tt>true</tt> to <tt>my_person.respond_to?("name")</tt>, <tt>my_person.respond_to?("name=")</tt>, and
|
|
# <tt>my_person.respond_to?("name?")</tt>.
|
|
def respond_to?(method, include_priv = false)
|
|
method_name = method.to_s
|
|
if attributes.nil?
|
|
return super
|
|
elsif attributes.has_key?(method_name)
|
|
return true
|
|
elsif ['?','='].include?(method_name.last) && attributes.has_key?(method_name.first(-1))
|
|
return true
|
|
end
|
|
# super must be called at the end of the method, because the inherited respond_to?
|
|
# would return true for generated readers, even if the attribute wasn't present
|
|
super
|
|
end
|
|
|
|
|
|
protected
|
|
def connection(refresh = false)
|
|
self.class.connection(refresh)
|
|
end
|
|
|
|
# Update the resource on the remote service.
|
|
def update
|
|
returning connection.put(element_path(prefix_options), to_xml, self.class.headers) do |response|
|
|
load_attributes_from_response(response)
|
|
end
|
|
end
|
|
|
|
# Create (i.e., save to the remote service) the new resource.
|
|
def create
|
|
returning connection.post(collection_path, to_xml, self.class.headers) do |response|
|
|
self.id = id_from_response(response)
|
|
load_attributes_from_response(response)
|
|
end
|
|
end
|
|
|
|
def load_attributes_from_response(response)
|
|
if response['Content-Length'] != "0" && response.body.strip.size > 0
|
|
load(self.class.format.decode(response.body))
|
|
end
|
|
end
|
|
|
|
# Takes a response from a typical create post and pulls the ID out
|
|
def id_from_response(response)
|
|
response['Location'][/\/([^\/]*?)(\.\w+)?$/, 1]
|
|
end
|
|
|
|
def element_path(options = nil)
|
|
self.class.element_path(to_param, options || prefix_options)
|
|
end
|
|
|
|
def collection_path(options = nil)
|
|
self.class.collection_path(options || prefix_options)
|
|
end
|
|
|
|
private
|
|
# Tries to find a resource for a given collection name; if it fails, then the resource is created
|
|
def find_or_create_resource_for_collection(name)
|
|
find_or_create_resource_for(name.to_s.singularize)
|
|
end
|
|
|
|
# Tries to find a resource in a non empty list of nested modules
|
|
# Raises a NameError if it was not found in any of the given nested modules
|
|
def find_resource_in_modules(resource_name, module_names)
|
|
receiver = Object
|
|
namespaces = module_names[0, module_names.size-1].map do |module_name|
|
|
receiver = receiver.const_get(module_name)
|
|
end
|
|
if namespace = namespaces.reverse.detect { |ns| ns.const_defined?(resource_name) }
|
|
return namespace.const_get(resource_name)
|
|
else
|
|
raise NameError
|
|
end
|
|
end
|
|
|
|
# Tries to find a resource for a given name; if it fails, then the resource is created
|
|
def find_or_create_resource_for(name)
|
|
resource_name = name.to_s.camelize
|
|
ancestors = self.class.name.split("::")
|
|
if ancestors.size > 1
|
|
find_resource_in_modules(resource_name, ancestors)
|
|
else
|
|
self.class.const_get(resource_name)
|
|
end
|
|
rescue NameError
|
|
resource = self.class.const_set(resource_name, Class.new(ActiveResource::Base))
|
|
resource.prefix = self.class.prefix
|
|
resource.site = self.class.site
|
|
resource
|
|
end
|
|
|
|
def split_options(options = {})
|
|
self.class.send!(:split_options, options)
|
|
end
|
|
|
|
def method_missing(method_symbol, *arguments) #:nodoc:
|
|
method_name = method_symbol.to_s
|
|
|
|
case method_name.last
|
|
when "="
|
|
attributes[method_name.first(-1)] = arguments.first
|
|
when "?"
|
|
attributes[method_name.first(-1)]
|
|
else
|
|
attributes.has_key?(method_name) ? attributes[method_name] : super
|
|
end
|
|
end
|
|
end
|
|
end
|