module ActiveModel::Validations::HelperMethods

def _merge_attributes(attr_names)

def _merge_attributes(attr_names)
  options = attr_names.extract_options!
  options.merge(:attributes => attr_names.flatten)
end

def validates_acceptance_of(*attr_names)

false value.
The method, proc or string should return or evaluate to a true or
:unless => Proc.new { |user| user.signup_step <= 2 }).
:unless => :skip_validation, or
determine if the validation should not occur (for example,
* :unless - Specifies a method, proc or string to call to
value.
method, proc or string should return or evaluate to a true or false
or :if => Proc.new { |user| user.signup_step > 2 }). The
if the validation should occur (e.g. :if => :allow_validation,
* :if - Specifies a method, proc or string to call to determine
before validation.
a database column, since the attribute is typecast from "1" to +true+
an HTML checkbox. This should be set to +true+ if you are validating
The default value is a string "1", which makes it easy to relate to
* :accept - Specifies value that is considered accepted.
is true).
* :allow_nil - Skip validation if attribute is +nil+ (default
:update).
:save, other options are :create and
* :on - Specifies when this validation is active (default is
accepted").
* :message - A custom error message (default is: "must be
Configuration options:

is not +nil+ and by default on save.
is entirely virtual. This check is performed only if +terms_of_service+
If the database column does not exist, the +terms_of_service+ attribute

end
validates_acceptance_of :eula, :message => "must be abided"
validates_acceptance_of :terms_of_service
class Person < ActiveRecord::Base

terms of service check box (or similar agreement). Example:
Encapsulates the pattern of wanting to validate the acceptance of a

def validates_acceptance_of(*attr_names)
  validates_with AcceptanceValidator, _merge_attributes(attr_names)
end

def validates_confirmation_of(*attr_names)

method, proc or string should return or evaluate to a true or false value.
:unless => Proc.new { |user| user.signup_step <= 2 }). The
:unless => :skip_validation, or
determine if the validation should not occur (e.g.
* :unless - Specifies a method, proc or string to call to
value.
method, proc or string should return or evaluate to a true or false
or :if => Proc.new { |user| user.signup_step > 2 }). The
if the validation should occur (e.g. :if => :allow_validation,
* :if - Specifies a method, proc or string to call to determine
:save, other options :create, :update).
* :on - Specifies when this validation is active (default is
confirmation").
* :message - A custom error message (default is: "doesn't match
Configuration options:

validates_presence_of :password_confirmation, :if => :password_changed?

to add a presence check for the confirmation attribute:
+nil+, and by default only on save. To require confirmation, make sure
NOTE: This check is performed only if +password_confirmation+ is not

attribute.
the validation adds accessors to the model for the confirmation
as an in-memory attribute for validating the password. To achieve this,
The added +password_confirmation+ attribute is virtual; it exists only

<%= password_field "person", "password_confirmation" %>
<%= password_field "person", "password" %>
View:

end
:message => "should match confirmation"
validates_confirmation_of :email_address,
validates_confirmation_of :user_name, :password
class Person < ActiveRecord::Base
Model:

address field with a confirmation. For example:
Encapsulates the pattern of wanting to validate a password or email

def validates_confirmation_of(*attr_names)
  validates_with ConfirmationValidator, _merge_attributes(attr_names)
end

def validates_exclusion_of(*attr_names)

method, proc or string should return or evaluate to a true or false value.
not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The
* :unless - Specifies a method, proc or string to call to determine if the validation should
method, proc or string should return or evaluate to a true or false value.
occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The
* :if - Specifies a method, proc or string to call to determine if the validation should
* :allow_blank - If set to true, skips this validation if the attribute is blank (default is +false+).
* :allow_nil - If set to true, skips this validation if the attribute is +nil+ (default is +false+).
* :message - Specifies a custom error message (default is: "is reserved").
* :in - An enumerable object of items that the value shouldn't be part of.
Configuration options:

end
validates_exclusion_of :format, :in => %w( mov avi ), :message => "extension %{value} is not allowed"
validates_exclusion_of :age, :in => 30..60, :message => "This site is only for under 30 and over 60"
validates_exclusion_of :username, :in => %w( admin superuser ), :message => "You don't belong here"
class Person < ActiveRecord::Base

Validates that the value of the specified attribute is not in a particular enumerable object.

def validates_exclusion_of(*attr_names)
  validates_with ExclusionValidator, _merge_attributes(attr_names)
end

def validates_format_of(*attr_names)

method, proc or string should return or evaluate to a true or false value.
not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The
* :unless - Specifies a method, proc or string to call to determine if the validation should
method, proc or string should return or evaluate to a true or false value.
occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The
* :if - Specifies a method, proc or string to call to determine if the validation should
* :on - Specifies when this validation is active (default is :save, other options :create, :update).
* :without - Regular expression that if the attribute does not match will result in a successful validation.
* :with - Regular expression that if the attribute matches will result in a successful validation.
* :allow_blank - If set to true, skips this validation if the attribute is blank (default is +false+).
* :allow_nil - If set to true, skips this validation if the attribute is +nil+ (default is +false+).
* :message - A custom error message (default is: "is invalid").
Configuration options:

or else an exception will be raised.
You must pass either :with or :without as an option. In addition, both must be a regular expression,

Note: use \A and \Z to match the start and end of the string, ^ and $ match the start/end of a line.

end
validates_format_of :email, :without => /NOSPAM/
class Person < ActiveRecord::Base

Alternatively, you can require that the specified attribute does _not_ match the regular expression:

end
validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, :on => :create
class Person < ActiveRecord::Base

You can require that the attribute matches the regular expression:
Validates whether the value of the specified attribute is of the correct form, going by the regular expression provided.

def validates_format_of(*attr_names)
  validates_with FormatValidator, _merge_attributes(attr_names)
end

def validates_inclusion_of(*attr_names)

def validates_inclusion_of(*attr_names)
  validates_with InclusionValidator, _merge_attributes(attr_names)
end

def validates_length_of(*attr_names)

Defaults to lambda{ |value| value.split(//) } which counts individual characters.
count words as in above example.)
* :tokenizer - Specifies how to split up the attribute string. (e.g. :tokenizer => lambda {|str| str.scan(/\w+/)} to
method, proc or string should return or evaluate to a true or false value.
not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The
* :unless - Specifies a method, proc or string to call to determine if the validation should
method, proc or string should return or evaluate to a true or false value.
occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The
* :if - Specifies a method, proc or string to call to determine if the validation should
* :on - Specifies when this validation is active (default is :save, other options :create, :update).
* :message - The error message to use for a :minimum, :maximum, or :is violation. An alias of the appropriate too_long/too_short/wrong_length message.
* :wrong_length - The error message if using the :is method and the attribute is the wrong size (default is: "is the wrong length (should be %{count} characters)").
* :too_short - The error message if the attribute goes under the minimum (default is: "is too short (min is %{count} characters)").
* :too_long - The error message if the attribute goes over the maximum (default is: "is too long (maximum is %{count} characters)").
* :allow_blank - Attribute may be blank; skip validation.
* :allow_nil - Attribute may be +nil+; skip validation.
* :in - A synonym(or alias) for :within.
* :within - A range specifying the minimum and maximum size of the attribute.
* :is - The exact size of the attribute.
* :maximum - The maximum size of the attribute.
* :minimum - The minimum size of the attribute.
Configuration options:

end
validates_length_of :essay, :minimum => 100, :too_short => "Your essay must be at least 100 words."), :tokenizer => lambda {|str| str.scan(/\w+/) }
validates_length_of :smurf_leader, :is => 4, :message => "papa is spelled with 4 characters... don't play me."
validates_length_of :zip_code, :minimum => 5, :too_short => "please enter at least 5 characters"
validates_length_of :user_name, :within => 6..20, :too_long => "pick a shorter name", :too_short => "pick a longer name"
validates_length_of :phone, :in => 7..32, :allow_blank => true
validates_length_of :fax, :in => 7..32, :allow_nil => true
validates_length_of :last_name, :maximum=>30, :message=>"less than 30 if you don't mind"
validates_length_of :first_name, :maximum=>30
class Person < ActiveRecord::Base

Validates that the specified attribute matches the length restrictions supplied. Only one option can be used at a time:

def validates_length_of(*attr_names)
  validates_with LengthValidator, _merge_attributes(attr_names)
end

def validates_numericality_of(*attr_names)

end
validates_numericality_of :width, :greater_than => :minimum_weight
validates_numericality_of :width, :less_than => Proc.new { |person| person.height }
class Person < ActiveRecord::Base

* :less_than_or_equal_to
* :less_than
* :equal_to
* :greater_than_or_equal_to
* :greater_than
The following checks can also be supplied with a proc or a symbol which corresponds to a method:

method, proc or string should return or evaluate to a true or false value.
not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The
* :unless - Specifies a method, proc or string to call to determine if the validation should
method, proc or string should return or evaluate to a true or false value.
occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The
* :if - Specifies a method, proc or string to call to determine if the validation should
* :even - Specifies the value must be an even number.
* :odd - Specifies the value must be an odd number.
* :less_than_or_equal_to - Specifies the value must be less than or equal the supplied value.
* :less_than - Specifies the value must be less than the supplied value.
* :equal_to - Specifies the value must be equal to the supplied value.
* :greater_than_or_equal_to - Specifies the value must be greater than or equal the supplied value.
* :greater_than - Specifies the value must be greater than the supplied value.
* :allow_nil - Skip validation if attribute is +nil+ (default is +false+). Notice that for fixnum and float columns empty strings are converted to +nil+.
* :only_integer - Specifies whether the value has to be an integer, e.g. an integral value (default is +false+).
* :on - Specifies when this validation is active (default is :save, other options :create, :update).
* :message - A custom error message (default is: "is not a number").
Configuration options:

end
validates_numericality_of :value, :on => :create
class Person < ActiveRecord::Base

/\A[\+\-]?\d+\Z/ (if only_integer is set to true).
a float with Kernel.Float (if only_integer is false) or applying it to the regular expression
Validates whether the value of the specified attribute is numeric by trying to convert it to

def validates_numericality_of(*attr_names)
  validates_with NumericalityValidator, _merge_attributes(attr_names)
end

def validates_presence_of(*attr_names)

The method, proc or string should return or evaluate to a true or false value.
not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }).
* unless - Specifies a method, proc or string to call to determine if the validation should
The method, proc or string should return or evaluate to a true or false value.
occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }).
* if - Specifies a method, proc or string to call to determine if the validation should
:update).
* on - Specifies when this validation is active (default is :save, other options :create,
* message - A custom error message (default is: "can't be blank").
Configuration options:

This is due to the way Object#blank? handles boolean values: false.blank? # => true.

you will want to use validates_inclusion_of :field_name, :in => [true, false].
If you want to validate the presence of a boolean field (where the real values are true and false),

The first_name attribute must be in the object and it cannot be blank.

end
validates_presence_of :first_name
class Person < ActiveRecord::Base

Validates that the specified attributes are not blank (as defined by Object#blank?). Happens by default on save. Example:

def validates_presence_of(*attr_names)
  validates_with PresenceValidator, _merge_attributes(attr_names)
end

Modules

Classes