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require 'active_support/core_ext/array/wrap'
require 'active_support/core_ext/object/blank'
module ActiveResource
class ResourceInvalid < ClientError #:nodoc:
end
# Active Resource validation is reported to and from this object, which is used by Base#save
# to determine whether the object in a valid state to be saved. See usage example in Validations.
class Errors < ActiveModel::Errors
# Grabs errors from an array of messages (like ActiveRecord::Validations).
# The second parameter directs the errors cache to be cleared (default)
# or not (by passing true).
def from_array(messages, save_cache = false)
clear unless save_cache
humanized_attributes = Hash[@base.attributes.keys.map { |attr_name| [attr_name.humanize, attr_name] }]
messages.each do |message|
attr_message = humanized_attributes.keys.detect do |attr_name|
if message[0, attr_name.size + 1] == "#{attr_name} "
add humanized_attributes[attr_name], message[(attr_name.size + 1)..-1]
end
end
self[:base] << message if attr_message.nil?
end
end
# Grabs errors from a json response.
def from_json(json, save_cache = false)
array = Array.wrap(ActiveSupport::JSON.decode(json)['errors']) rescue []
from_array array, save_cache
end
# Grabs errors from an XML response.
def from_xml(xml, save_cache = false)
array = Array.wrap(Hash.from_xml(xml)['errors']['error']) rescue []
from_array array, save_cache
end
end
# 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
# <tt>validates_presence_of :first_name, :last_name</tt> 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)
#
module Validations
extend ActiveSupport::Concern
include ActiveModel::Validations
included do
alias_method_chain :save, :validation
end
# Validate a resource and save (POST) it to the remote web service.
# If any local validations fail - the save (POST) will not be attempted.
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
# Loads the set of remote errors into the object's Errors based on the
# content-type of the error-block received.
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
# 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.login == ''
# my_person.valid?
# # => false
#
def valid?
super
load_remote_errors(@remote_errors, true) if defined?(@remote_errors) && @remote_errors.present?
errors.empty?
end
# Returns the Errors object that holds all information about attribute error messages.
def errors
@errors ||= Errors.new(self)
end
end
end
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