Module: ActiveResource::Validations

Extended by:
ActiveSupport::Concern
Includes:
ActiveModel::Validations
Included in:
Base
Defined in:
lib/active_resource/validations.rb

Overview

Module to support validation and errors with Active Resource objects. The module overrides Base#save to rescue ActiveResource::ResourceInvalid exceptions and parse the errors returned in the web service response. The module also adds an errors collection that mimics the interface of the errors provided by ActiveModel::Errors.

Example

Consider a Person resource on the server requiring both a first_name and a last_name with a validates_presence_of :first_name, :last_name declaration in the model:

person = Person.new(:first_name => "Jim", :last_name => "")
person.save                   # => false (server returns an HTTP 422 status code and errors)
person.valid?                 # => false
person.errors.empty?          # => false
person.errors.count           # => 1
person.errors.full_messages   # => ["Last name can't be empty"]
person.errors[:last_name]  # => ["can't be empty"]
person.last_name = "Halpert"
person.save                   # => true (and person is now saved to the remote service)

Instance Method Summary collapse

Instance Method Details

#errorsObject

Returns the Errors object that holds all information about attribute error messages.


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# File 'lib/active_resource/validations.rb', line 169

def errors
  @errors ||= Errors.new(self)
end

#load_remote_errors(remote_errors, save_cache = false) ⇒ Object

Loads the set of remote errors into the object's Errors based on the content-type of the error-block received.


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# File 'lib/active_resource/validations.rb', line 133

def load_remote_errors(remote_errors, save_cache = false ) #:nodoc:
  case self.class.format
  when ActiveResource::Formats[:xml]
    errors.from_xml(remote_errors.response.body, save_cache)
  when ActiveResource::Formats[:json]
    errors.from_json(remote_errors.response.body, save_cache)
  end
end

#save_with_validation(options = {}) ⇒ Object

Validate a resource and save (POST) it to the remote web service. If any local validations fail - the save (POST) will not be attempted.


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# File 'lib/active_resource/validations.rb', line 108

def save_with_validation(options={})
  perform_validation = options[:validate] != false

  # clear the remote validations so they don't interfere with the local
  # ones. Otherwise we get an endless loop and can never change the
  # fields so as to make the resource valid.
  @remote_errors = nil
  if perform_validation && valid? || !perform_validation
    save_without_validation
    true
  else
    false
  end
rescue ResourceInvalid => error
  # cache the remote errors because every call to <tt>valid?</tt> clears
  # all errors. We must keep a copy to add these back after local
  # validations.
  @remote_errors = error
  load_remote_errors(@remote_errors, true)
  false
end

#valid?Boolean

Checks for errors on an object (i.e., is resource.errors empty?).

Runs all the specified local validations and returns true if no errors were added, otherwise false. Runs local validations (eg those on your Active Resource model), and also any errors returned from the remote system the last time we saved. Remote errors can only be cleared by trying to re-save the resource.

Examples

my_person = Person.create(params[:person])
my_person.valid?
# => true

my_person.errors.add('login', 'can not be empty') if my_person. == ''
my_person.valid?
# => false

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# File 'lib/active_resource/validations.rb', line 160

def valid?
  run_callbacks :validate do
    super
    load_remote_errors(@remote_errors, true) if defined?(@remote_errors) && @remote_errors.present?
    errors.empty?
  end
end