Module: ActiveRecord::Validations::ClassMethods
- Defined in:
- lib/active_record/validations.rb
Overview
All of the following validations are defined in the class scope of the model that you’re interested in validating. They offer a more declarative way of specifying when the model is valid and when it is not. It is recommended to use these over the low-level calls to validate and validate_on_create when possible.
Constant Summary collapse
- DEFAULT_VALIDATION_OPTIONS =
{ :on => :save, :allow_nil => false, :message => nil }.freeze
- DEFAULT_SIZE_VALIDATION_OPTIONS =
DEFAULT_VALIDATION_OPTIONS.merge( :too_long => ActiveRecord::Errors.[:too_long], :too_short => ActiveRecord::Errors.[:too_short], :wrong_length => ActiveRecord::Errors.[:wrong_length] ).freeze
- ALL_RANGE_OPTIONS =
[ :is, :within, :in, :minimum, :maximum ].freeze
Instance Method Summary collapse
- #validate(*methods, &block) ⇒ Object
- #validate_on_create(*methods, &block) ⇒ Object
- #validate_on_update(*methods, &block) ⇒ Object
-
#validates_acceptance_of(*attr_names) ⇒ Object
Encapsulates the pattern of wanting to validate the acceptance of a terms of service check box (or similar agreement).
-
#validates_associated(*attr_names) ⇒ Object
Validates whether the associated object or objects are all themselves valid.
-
#validates_confirmation_of(*attr_names) ⇒ Object
Encapsulates the pattern of wanting to validate a password or email address field with a confirmation.
-
#validates_each(*attrs) ⇒ Object
Validates each attribute against a block.
-
#validates_format_of(*attr_names) ⇒ Object
Validates whether the value of the specified attribute is of the correct form by matching it against the regular expression provided.
-
#validates_inclusion_of(*attr_names) ⇒ Object
Validates whether the value of the specified attribute is available in a particular enumerable object.
-
#validates_length_of(*attrs) ⇒ Object
(also: #validates_size_of)
Validates that the specified attribute matches the length restrictions supplied.
-
#validates_numericality_of(*attr_names) ⇒ Object
Validates whether the value of the specified attribute is numeric by trying to convert it to a float with Kernel.Float (if
integer
is false) or applying it to the regular expression/^[+\-]?\d+$/
(ifinteger
is set to true). -
#validates_presence_of(*attr_names) ⇒ Object
Validates that the specified attributes are neither nil nor empty.
-
#validates_uniqueness_of(*attr_names) ⇒ Object
Validates whether the value of the specified attributes are unique across the system.
Instance Method Details
#validate(*methods, &block) ⇒ Object
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# File 'lib/active_record/validations.rb', line 214 def validate(*methods, &block) methods << block if block_given? write_inheritable_set(:validate, methods) end |
#validate_on_create(*methods, &block) ⇒ Object
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# File 'lib/active_record/validations.rb', line 219 def validate_on_create(*methods, &block) methods << block if block_given? write_inheritable_set(:validate_on_create, methods) end |
#validate_on_update(*methods, &block) ⇒ Object
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# File 'lib/active_record/validations.rb', line 224 def validate_on_update(*methods, &block) methods << block if block_given? write_inheritable_set(:validate_on_update, methods) end |
#validates_acceptance_of(*attr_names) ⇒ Object
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
The terms_of_service attribute is entirely virtual. No database column is needed. This check is performed only if terms_of_service is not nil and by default on save.
Configuration options:
-
message
- A custom error message (default is: “can’t be empty”) -
on
- Specifies when this validation is active (default is :save, other options :create, :update) -
accept
- Specifies value that is considered accepted. The default value is a string “1”, which
makes it easy to relate to an HTML checkbox.
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# File 'lib/active_record/validations.rb', line 301 def validates_acceptance_of(*attr_names) configuration = { :message => ActiveRecord::Errors.[:accepted], :on => :save, :allow_nil => true, :accept => "1" } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) attr_accessor *attr_names validates_each(attr_names,configuration) do |record, attr_name, value| record.errors.add(attr_name, configuration[:message]) unless value == configuration[:accept] end end |
#validates_associated(*attr_names) ⇒ Object
Validates whether the associated object or objects are all themselves valid. Works with any kind of association.
class Book < ActiveRecord::Base
has_many :pages
belongs_to :library
validates_associated :pages, :library
end
Warning: If, after the above definition, you then wrote:
class Page < ActiveRecord::Base
belongs_to :book
validates_associated :book
end
this would specify a circular dependency and cause infinite recursion. The Rails team recommends against this practice.
Configuration options:
-
on
Specifies when this validation is active (default is :save, other options :create, :update)
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# File 'lib/active_record/validations.rb', line 494 def validates_associated(*attr_names) configuration = { :message => ActiveRecord::Errors.[:invalid], :on => :save } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) validates_each(attr_names, configuration) do |record, attr_name, value| record.errors.add(attr_name, configuration[:message]) unless (value.is_a?(Array) ? value : [value]).inject(true) { |memo, r| (r.nil? or r.valid?) and memo } end end |
#validates_confirmation_of(*attr_names) ⇒ Object
Encapsulates the pattern of wanting to validate a password or email address field with a confirmation. 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 person has to already have a password attribute (a column in the people table), but the password_confirmation is virtual. It exists only as an in-memory variable for validating the password. This check is performed only if password_confirmation is not nil and by default on save.
Configuration options:
-
message
- A custom error message (default is: “doesn’t match confirmation”) -
on
- Specifies when this validation is active (default is :save, other options :create, :update)
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# File 'lib/active_record/validations.rb', line 273 def validates_confirmation_of(*attr_names) configuration = { :message => ActiveRecord::Errors.[:confirmation], :on => :save } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) attr_accessor *(attr_names.map { |n| "#{n}_confirmation" }) validates_each(attr_names, configuration) do |record, attr_name, value| record.errors.add(attr_name, configuration[:message]) unless record.send("#{attr_name}_confirmation").nil? or value == record.send("#{attr_name}_confirmation") end end |
#validates_each(*attrs) ⇒ Object
Validates each attribute against a block.
class Person < ActiveRecord::Base
validates_each :first_name, :last_name do |record, attr|
record.errors.add attr, 'starts with z.' if attr[0] == ?z
end
end
Options:
-
on
- Specifies when this validation is active (default is :save, other options :create, :update) -
allow_nil
- Skip validation if attribute is nil.
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# File 'lib/active_record/validations.rb', line 240 def validates_each(*attrs) = attrs.last.is_a?(Hash) ? attrs.pop.symbolize_keys : {} attrs = attrs.flatten # Declare the validation. send(validation_method([:on] || :save)) do |record| attrs.each do |attr| value = record.send(attr) next if value.nil? && [:allow_nil] yield record, attr, value end end end |
#validates_format_of(*attr_names) ⇒ Object
Validates whether the value of the specified attribute is of the correct form by matching it against the regular expression provided.
class Person < ActiveRecord::Base
validates_format_of :email, :with => /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/, :on => :create
end
A regular expression must be provided or else an exception will be raised.
Configuration options:
-
message
- A custom error message (default is: “is invalid”) -
with
- The regular expression used to validate the format with (note: must be supplied!) -
on
Specifies when this validation is active (default is :save, other options :create, :update)
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# File 'lib/active_record/validations.rb', line 438 def validates_format_of(*attr_names) configuration = { :message => ActiveRecord::Errors.[:invalid], :on => :save, :with => nil } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) raise(ArgumentError, "A regular expression must be supplied as the :with option of the configuration hash") unless configuration[:with].is_a?(Regexp) validates_each(attr_names, configuration) do |record, attr_name, value| record.errors.add(attr_name, configuration[:message]) unless value.to_s =~ configuration[:with] end end |
#validates_inclusion_of(*attr_names) ⇒ Object
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 ), :message=>"woah! what are you then!??!!"
validates_inclusion_of :age, :in=>0..99
end
Configuration options:
-
in
- An enumerable object of available items -
message
- Specifies a customer error message (default is: “is not included in the list”) -
allow_nil
- If set to true, skips this validation if the attribute is null (default is: false)
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# File 'lib/active_record/validations.rb', line 460 def validates_inclusion_of(*attr_names) configuration = { :message => ActiveRecord::Errors.[:inclusion], :on => :save } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) enum = configuration[:in] || configuration[:within] raise(ArgumentError, "An object with the method include? is required must be supplied as the :in option of the configuration hash") unless enum.respond_to?("include?") validates_each(attr_names, configuration) do |record, attr_name, value| record.errors.add(attr_name, configuration[:message]) unless enum.include?(value) end end |
#validates_length_of(*attrs) ⇒ Object Also known as: validates_size_of
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 %d if you don't mind"
validates_length_of :fax, :in => 7..32, :allow_nil => true
validates_length_of :user_name, :within => 6..20, :too_long => "pick a shorter name", :too_short => "pick a longer name"
validates_length_of :fav_bra_size, :minimum=>1, :too_short=>"please enter at least %d character"
validates_length_of :smurf_leader, :is=>4, :message=>"papa is spelled with %d characters... don't play me."
end
Configuration options:
-
minimum
- The minimum size of the attribute -
maximum
- The maximum size of the attribute -
is
- The exact size of the attribute -
within
- A range specifying the minimum and maximum size of the attribute -
in
- A synonym(or alias) for :within -
allow_nil
- Attribute may be nil; skip validation. -
too_long
- The error message if the attribute goes over the maximum (default is: “is too long (max is %d characters)”) -
too_short
- The error message if the attribute goes under the minimum (default is: “is too short (min is %d characters)”) -
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 %d characters)”) -
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 -
on
- Specifies when this validation is active (default is :save, other options :create, :update)
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# File 'lib/active_record/validations.rb', line 354 def validates_length_of(*attrs) # Merge given options with defaults. = DEFAULT_SIZE_VALIDATION_OPTIONS.dup .update(attrs.pop.symbolize_keys) if attrs.last.is_a?(Hash) # Ensure that one and only one range option is specified. = ALL_RANGE_OPTIONS & .keys case .size when 0 raise ArgumentError, 'Range unspecified. Specify the :within, :maximum, :minimum, or :is option.' when 1 # Valid number of options; do nothing. else raise ArgumentError, 'Too many range options specified. Choose only one.' end # Get range option and value. option = .first option_value = [.first] # Declare different validations per option. validity_checks = { :is => "==", :minimum => ">=", :maximum => "<=" } = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long } case option when :within, :in raise ArgumentError, ':within must be a Range' unless option_value.is_a?(Range) # ' validates_length_of attrs, :minimum => option_value.begin, :allow_nil => [:allow_nil] validates_length_of attrs, :maximum => option_value.end, :allow_nil => [:allow_nil] when :is, :minimum, :maximum raise ArgumentError, ":#{option} must be a nonnegative Integer" unless option_value.is_a?(Integer) and option_value >= 0 # ' = [:message] || [[option]] = ( % option_value) rescue validates_each(attrs, ) do |record, attr, value| record.errors.add(attr, ) if value.nil? or !value.size.method(validity_checks[option])[option_value] end end end |
#validates_numericality_of(*attr_names) ⇒ Object
Validates whether the value of the specified attribute is numeric by trying to convert it to a float with Kernel.Float (if integer
is false) or applying it to the regular expression /^[+\-]?\d+$/
(if integer
is set to true).
class Person < ActiveRecord::Base
validates_numericality_of :value, :on => :create
end
Configuration options:
-
message
- A custom error message (default is: “is not a number”) -
on
Specifies when this validation is active (default is :save, other options :create, :update) -
only_integer
Specifies whether the value has to be an integer, e.g. an integral value (default is false) -
allow_nil
Skip validation if attribute is nil (default is false). Notice that for fixnum and float columsn empty strings are converted to nil
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# File 'lib/active_record/validations.rb', line 517 def validates_numericality_of(*attr_names) configuration = { :message => ActiveRecord::Errors.[:not_a_number], :on => :save, :only_integer => false, :allow_nil => false } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) if configuration[:only_integer] validates_each(attr_names,configuration) do |record, attr_name,value| record.errors.add(attr_name, configuration[:message]) unless record.send("#{attr_name}_before_type_cast").to_s =~ /^[+-]?\d+$/ end else validates_each(attr_names,configuration) do |record, attr_name,value| begin Kernel.Float(record.send("#{attr_name}_before_type_cast").to_s) rescue ArgumentError, TypeError record.errors.add(attr_name, configuration[:message]) end end end end |
#validates_presence_of(*attr_names) ⇒ Object
Validates that the specified attributes are neither nil nor empty. Happens by default on save.
Configuration options:
-
message
- A custom error message (default is: “has already been taken”) -
on
- Specifies when this validation is active (default is :save, other options :create, :update)
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# File 'lib/active_record/validations.rb', line 317 def validates_presence_of(*attr_names) configuration = { :message => ActiveRecord::Errors.[:empty], :on => :save } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) # can't use validates_each here, because it cannot cope with non-existant attributes, # while errors.add_on_empty can attr_names.each do |attr_name| send(validation_method(configuration[:on])) do |record| record.errors.add_on_empty(attr_name,configuration[:message]) end end end |
#validates_uniqueness_of(*attr_names) ⇒ Object
Validates whether the value of the specified attributes are unique across the system. Useful for making sure that only one user can be named “davidhh”.
class Person < ActiveRecord::Base
validates_uniqueness_of :user_name, :scope => "account_id"
end
When the record is created, a check is performed to make sure that no record exist in the database with the given value for the specified attribute (that maps to a column). When the record is updated, the same check is made but disregarding the record itself.
Configuration options:
-
message
- Specifies a custom error message (default is: “has already been taken”) -
scope
- Ensures that the uniqueness is restricted to a condition of “scope = record.scope”
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# File 'lib/active_record/validations.rb', line 410 def validates_uniqueness_of(*attr_names) configuration = { :message => ActiveRecord::Errors.[:taken] } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) if scope = configuration[:scope] validates_each(attr_names,configuration) do |record, attr_name, value| record.errors.add(attr_name, configuration[:message]) if record.class.find_first(record.new_record? ? ["#{attr_name} = ? AND #{scope} = ?", record.send(attr_name), record.send(scope)] : ["#{attr_name} = ? AND #{record.class.primary_key} <> ? AND #{scope} = ?", record.send(attr_name), record.send(:id), record.send(scope)]) end else validates_each(attr_names,configuration) do |record, attr_name, value| record.errors.add(attr_name, configuration[:message]) if record.class.find_first(record.new_record? ? ["#{attr_name} = ?", record.send(attr_name)] : ["#{attr_name} = ? AND #{record.class.primary_key} <> ?", record.send(attr_name), record.send(:id) ] ) end end end |