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
include Enumerable
attr_reader :errors
delegate :empty?, :to => :errors
def initialize(base) # :nodoc:
@base, @errors = base, {}
end
# Add an error to the base Active Resource object rather than an attribute.
#
# ==== Examples
# my_folder = Folder.find(1)
# my_folder.errors.add_to_base("You can't edit an existing folder")
# my_folder.errors.on_base
# # => "You can't edit an existing folder"
#
# my_folder.errors.add_to_base("This folder has been tagged as frozen")
# my_folder.valid?
# # => false
# my_folder.errors.on_base
# # => ["You can't edit an existing folder", "This folder has been tagged as frozen"]
#
def add_to_base(msg)
add(:base, msg)
end
# Adds an error to an Active Resource object's attribute (named for the +attribute+ parameter)
# with the error message in +msg+.
#
# ==== Examples
# my_resource = Node.find(1)
# my_resource.errors.add('name', 'can not be "base"') if my_resource.name == 'base'
# my_resource.errors.on('name')
# # => 'can not be "base"!'
#
# my_resource.errors.add('desc', 'can not be blank') if my_resource.desc == ''
# my_resource.valid?
# # => false
# my_resource.errors.on('desc')
# # => 'can not be blank!'
#
def add(attribute, msg)
@errors[attribute.to_s] = [] if @errors[attribute.to_s].nil?
@errors[attribute.to_s] << msg
end
# Returns true if the specified +attribute+ has errors associated with it.
#
# ==== Examples
# my_resource = Disk.find(1)
# my_resource.errors.add('location', 'must be Main') unless my_resource.location == 'Main'
# my_resource.errors.on('location')
# # => 'must be Main!'
#
# my_resource.errors.invalid?('location')
# # => true
# my_resource.errors.invalid?('name')
# # => false
def invalid?(attribute)
!@errors[attribute.to_s].nil?
end
# A method to return the errors associated with +attribute+, which returns nil, if no errors are
# associated with the specified +attribute+, the error message if one error is associated with the specified +attribute+,
# or an array of error messages if more than one error is associated with the specified +attribute+.
#
# ==== Examples
# my_person = Person.new(params[:person])
# my_person.errors.on('login')
# # => nil
#
# my_person.errors.add('login', 'can not be empty') if my_person.login == ''
# my_person.errors.on('login')
# # => 'can not be empty'
#
# my_person.errors.add('login', 'can not be longer than 10 characters') if my_person.login.length > 10
# my_person.errors.on('login')
# # => ['can not be empty', 'can not be longer than 10 characters']
def on(attribute)
errors = @errors[attribute.to_s]
return nil if errors.nil?
errors.size == 1 ? errors.first : errors
end
alias :[] :on
# A method to return errors assigned to +base+ object through add_to_base, which returns nil, if no errors are
# associated with the specified +attribute+, the error message if one error is associated with the specified +attribute+,
# or an array of error messages if more than one error is associated with the specified +attribute+.
#
# ==== Examples
# my_account = Account.find(1)
# my_account.errors.on_base
# # => nil
#
# my_account.errors.add_to_base("This account is frozen")
# my_account.errors.on_base
# # => "This account is frozen"
#
# my_account.errors.add_to_base("This account has been closed")
# my_account.errors.on_base
# # => ["This account is frozen", "This account has been closed"]
#
def on_base
on(:base)
end
# Yields each attribute and associated message per error added.
#
# ==== Examples
# my_person = Person.new(params[:person])
#
# my_person.errors.add('login', 'can not be empty') if my_person.login == ''
# my_person.errors.add('password', 'can not be empty') if my_person.password == ''
# messages = ''
# my_person.errors.each {|attr, msg| messages += attr.humanize + " " + msg + "<br />"}
# messages
# # => "Login can not be empty<br />Password can not be empty<br />"
#
def each
@errors.each_key { |attr| @errors[attr].each { |msg| yield attr, msg } }
end
# Yields each full error message added. So Person.errors.add("first_name", "can't be empty") will be returned
# through iteration as "First name can't be empty".
#
# ==== Examples
# my_person = Person.new(params[:person])
#
# my_person.errors.add('login', 'can not be empty') if my_person.login == ''
# my_person.errors.add('password', 'can not be empty') if my_person.password == ''
# messages = ''
# my_person.errors.each_full {|msg| messages += msg + "<br/>"}
# messages
# # => "Login can not be empty<br />Password can not be empty<br />"
#
def each_full
full_messages.each { |msg| yield msg }
end
# Returns all the full error messages in an array.
#
# ==== Examples
# my_person = Person.new(params[:person])
#
# my_person.errors.add('login', 'can not be empty') if my_person.login == ''
# my_person.errors.add('password', 'can not be empty') if my_person.password == ''
# messages = ''
# my_person.errors.full_messages.each {|msg| messages += msg + "<br/>"}
# messages
# # => "Login can not be empty<br />Password can not be empty<br />"
#
def full_messages
full_messages = []
@errors.each_key do |attr|
@errors[attr].each do |msg|
next if msg.nil?
if attr == "base"
full_messages << msg
else
full_messages << [attr.humanize, msg].join(' ')
end
end
end
full_messages
end
def clear
@errors = {}
end
# Returns the total number of errors added. Two errors added to the same attribute will be counted as such
# with this as well.
#
# ==== Examples
# my_person = Person.new(params[:person])
# my_person.errors.size
# # => 0
#
# my_person.errors.add('login', 'can not be empty') if my_person.login == ''
# my_person.errors.add('password', 'can not be empty') if my_person.password == ''
# my_person.error.size
# # => 2
#
def size
@errors.values.inject(0) { |error_count, attribute| error_count + attribute.size }
end
alias_method :count, :size
alias_method :length, :size
# Grabs errors from the XML response.
def from_xml(xml)
clear
humanized_attributes = @base.attributes.keys.inject({}) { |h, attr_name| h.update(attr_name.humanize => attr_name) }
messages = Array.wrap(Hash.from_xml(xml)['errors']['error']) rescue []
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
add_to_base message if attr_message.nil?
end
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 ActiveRecord::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.on(:last_name) # => "can't be empty"
# person.last_name = "Halpert"
# person.save # => true (and person is now saved to the remote service)
#
module Validations
def self.included(base) # :nodoc:
base.class_eval do
alias_method_chain :save, :validation
end
end
# Validate a resource and save (POST) it to the remote web service.
def save_with_validation
save_without_validation
true
rescue ResourceInvalid => error
errors.from_xml(error.response.body)
false
end
# Checks for errors on an object (i.e., is resource.errors empty?).
#
# ==== 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?
errors.empty?
end
# Returns the Errors object that holds all information about attribute error messages.
def errors
@errors ||= Errors.new(self)
end
end
end
