Encapsulates the pattern of wanting to validate the acceptance of a terms of service check box (or similar agreement). Example:
class Person < ActiveRecord::Base validates_acceptance_of :terms_of_service validates_acceptance_of :eula, :message => "must be abided" end
If the database column does not exist, the terms_of_service attribute is entirely virtual. This check is performed only if terms_of_service is not nil and by default on save.
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Encapsulates the pattern of wanting to validate a password or email address field with a confirmation. For example:
Model: class Person < ActiveRecord::Base validates_confirmation_of :user_name, :password validates_confirmation_of :email_address, :message => "should match confirmation" end View: <%= password_field "person", "password" %> <%= password_field "person", "password_confirmation" %>
The added password_confirmation attribute is virtual; it exists only as an in-memory attribute for validating the password. To achieve this, the validation adds accessors to the model for the confirmation attribute.
NOTE: This check is performed only if password_confirmation is not nil, and by default only on save. To require confirmation, make sure to add a presence check for the confirmation attribute:
validates_presence_of :password_confirmation, :if => :password_changed?
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Validates that the value of the specified attribute is not in a particular enumerable object.
class Person < ActiveRecord::Base validates_exclusion_of :username, :in => %w( admin superuser ), :message => "You don't belong here" validates_exclusion_of :age, :in => 30..60, :message => "This site is only for under 30 and over 60" validates_exclusion_of :format, :in => %w( mov avi ), :message => "extension %{value} is not allowed" validates_exclusion_of :password, :in => lambda { |p| [p.username, p.first_name] }, :message => "should not be the same as your username or first name" end
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Validates whether the value of the specified attribute is of the correct form, going by the regular expression provided. You can require that the attribute matches the regular expression:
class Person < ActiveRecord::Base validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, :on => :create end
Alternatively, you can require that the specified attribute does not match the regular expression:
class Person < ActiveRecord::Base validates_format_of :email, :without => /NOSPAM/ end
You can also provide a proc or lambda which will determine the regular expression that will be used to validate the attribute
class Person < ActiveRecord::Base # Admin can have number as a first letter in their screen name validates_format_of :screen_name, :with => lambda{ |person| person.admin? ? /\A[a-z0-9][a-z0-9_\-]*\Z/i : /\A[a-z][a-z0-9_\-]*\Z/i } end
Note: use \A and \Z to match the start and end of the string, ^ and $ match the start/end of a line.
You must pass either :with or :without as an option. In addition, both must be a regular expression or a proc or lambda, or else an exception will be raised.
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Validates whether the value of the specified attribute is available in a particular enumerable object.
class Person < ActiveRecord::Base validates_inclusion_of :gender, :in => %w( m f ) validates_inclusion_of :age, :in => 0..99 validates_inclusion_of :format, :in => %w( jpg gif png ), :message => "extension %{value} is not included in the list" validates_inclusion_of :states, :in => lambda{ |person| STATES[person.country] } end
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Validates that the specified attribute matches the length restrictions supplied. Only one option can be used at a time:
class Person < ActiveRecord::Base validates_length_of :first_name, :maximum => 30 validates_length_of :last_name, :maximum => 30, :message => "less than 30 if you don't mind" validates_length_of :fax, :in => 7..32, :allow_nil => true validates_length_of :phone, :in => 7..32, :allow_blank => true validates_length_of :user_name, :within => 6..20, :too_long => "pick a shorter name", :too_short => "pick a longer name" validates_length_of :zip_code, :minimum => 5, :too_short => "please enter at least 5 characters" validates_length_of :smurf_leader, :is => 4, :message => "papa is spelled with 4 characters... don't play me." validates_length_of :essay, :minimum => 100, :too_short => "Your essay must be at least 100 words.", :tokenizer => lambda { |str| str.scan(/\w+/) } end
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Validates whether the value of the specified attribute is numeric by trying to convert it to a float with Kernel.Float (if only_integer is false) or applying it to the regular expression /\A[+\-]?\d+\Z/ (if only_integer is set to true).
class Person < ActiveRecord::Base validates_numericality_of :value, :on => :create end
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The following checks can also be supplied with a proc or a symbol which corresponds to a method:
class Person < ActiveRecord::Base
validates_numericality_of :width, :less_than => Proc.new { |person| person.height } validates_numericality_of :width, :greater_than => :minimum_weight
end
Validates that the specified attributes are not blank (as defined by Object#blank?). Happens by default on save. Example:
class Person < ActiveRecord::Base validates_presence_of :first_name end
The first_name attribute must be in the object and it cannot be blank.
If you want to validate the presence of a boolean field (where the real values are true and false), you will want to use validates_inclusion_of :field_name, :in => [true, false].
This is due to the way Object#blank? handles boolean values: false.blank? # => true.
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