Module: AntMapper::Validations::ClassMethods

Defined in:
lib/ant_mapper/validations.rb

Overview

Ant Mapper classes can implement validations in several ways. The highest level, easiest to read, and recommended approach is to use the declarative validates_..._of class methods (and validates_associated) documented below. These are sufficient for most model validations.

Slightly lower level is validates_each. It provides some of the same options as the purely declarative validation methods, but like all the lower-level approaches it requires manually adding to the errors collection when the record is invalid.

At a yet lower level, a model can use the class methods validate, validate_on_create and validate_on_update to add validation methods or blocks. These are AntSupport::Callbacks and follow the same rules of inheritance and chaining.

The lowest level style is to define the instance methods validate, validate_on_create and validate_on_update as documented in AntObject::Validations.

validate, validate_on_create and validate_on_update Class Methods

Calls to these methods add a validation method or block to the class. Again, this approach is recommended only when the higher-level methods documented below (validates_..._of and validates_associated) are insufficient to handle the required validation.

This can be done with a symbol pointing to a method:

class Comment < AntMapper::Base
  validate :must_be_friends

  def must_be_friends
    errors.add_to_base("Must be friends to leave a comment") unless commenter.friend_of?(commentee)
  end
end

Or with a block which is passed the current record to be validated:

class Comment < AntMapper::Base
  validate do |comment|
    comment.must_be_friends
  end

  def must_be_friends
    errors.add_to_base("Must be friends to leave a comment") unless commenter.friend_of?(commentee)
  end
end

This usage applies to validate_on_create and validate_on_update as well.

Constant Summary collapse

DEFAULT_VALIDATION_OPTIONS = 
{
  :on => :save,
  :allow_nil => false,
  :allow_blank => false,
  :message => nil
}.freeze
ALL_RANGE_OPTIONS = 
[ :is, :within, :in, :minimum, :maximum ].freeze
ALL_NUMERICALITY_CHECKS = 
{ :greater_than => '>', :greater_than_or_equal_to => '>=',
:equal_to => '==', :less_than => '<', :less_than_or_equal_to => '<=',
:odd => 'odd?', :even => 'even?' }.freeze

Instance Method Summary collapse

Instance Method Details

#create!(attributes = nil, &block) ⇒ Object

Creates an object just like Base.create but calls save! instead of save so an exception is raised if the record is invalid.



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# File 'lib/ant_mapper/validations.rb', line 610

def create!(attributes = nil, &block)
  if attributes.is_a?(Array)
    attributes.collect { |attr| create!(attr, &block) }
  else
    object = new(attributes)
    yield(object) if block_given?
    object.save!
    object
  end
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 < AntMapper::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.

Configuration options:

  • :message - A custom error message (default is: “must be accepted”).

  • :on - Specifies when this validation is active (default is :save, other options :create, :update).

  • :allow_nil - Skip validation if attribute is nil (default is true).

  • :accept - Specifies value that is considered accepted. The default value is a string “1”, which makes it easy to relate to an HTML checkbox. This should be set to true if you are validating a database column, since the attribute is typecast from “1” to true before validation.

  • :if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

  • :unless - Specifies a method, proc or string to call to determine if the validation should not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The method, proc or string should return or evaluate to a true or false value.



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# File 'lib/ant_mapper/validations.rb', line 353

def validates_acceptance_of(*attr_names)
  configuration = { :on => :save, :allow_nil => true, :accept => "1" }
  configuration.update(attr_names.extract_options!)

  names = attr_names.reject { |name| self.class.attributes.include?(name.to_s) }
  attr_accessor(*names)

  validates_each(attr_names,configuration) do |record, attr_name, value|
    unless value == configuration[:accept]
      record.errors.add(attr_name, :default => configuration[:message])
    end
  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 < AntMapper::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?

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).

  • :if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

  • :unless - Specifies a method, proc or string to call to determine if the validation should not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The method, proc or string should return or evaluate to a true or false value.



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# File 'lib/ant_mapper/validations.rb', line 317

def validates_confirmation_of(*attr_names)
  configuration = { :on => :save }
  configuration.update(attr_names.extract_options!)

  attr_accessor(*(attr_names.map { |n| "#{n}_confirmation" }))

  validates_each(attr_names, configuration) do |record, attr_name, value|
    unless record.send("#{attr_name}_confirmation").nil? or value == record.send("#{attr_name}_confirmation")
      record.errors.add(attr_name, :default => configuration[:message])
    end
  end
end

#validates_each(*attrs) ⇒ Object

Validates each attribute against a block.

class Person < AntMapper::Base
  validates_each :first_name, :last_name do |record, attr, value|
    record.errors.add attr, 'starts with z.' if value[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.

  • :allow_blank - Skip validation if attribute is blank.

  • :if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

  • :unless - Specifies a method, proc or string to call to determine if the validation should not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The method, proc or string should return or evaluate to a true or false value.



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# File 'lib/ant_mapper/validations.rb', line 275

def validates_each(*attrs)
  options = attrs.extract_options!.symbolize_keys
  attrs   = attrs.flatten

  # Declare the validation.
  send(validation_method(options[:on] || :save), options) do |record|
    attrs.each do |attr|
      value = record.send(attr)
      next if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
      yield record, attr, value
    end
  end
end

#validates_exclusion_of(*attr_names) ⇒ Object

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

class Person < AntMapper::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"
end

Configuration options:

  • in - An enumerable object of items that the value shouldn’t be part of

  • message - Specifies a customer error message (default is: “is reserved”)

  • allow_nil - If set to true, skips this validation if the attribute is null (default is: false)

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

Raises:

  • (ArgumentError) 


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# File 'lib/ant_mapper/validations.rb', line 557

def validates_exclusion_of(*attr_names)
  configuration = { :message => AntMapper::Errors.default_error_messages[:exclusion], :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]) if enum.include?(value)
  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 < AntMapper::Base
  validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, :on => :create
end

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

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)

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

Raises:

  • (ArgumentError) 


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# File 'lib/ant_mapper/validations.rb', line 505

def validates_format_of(*attr_names)
  configuration = { :message => AntMapper::Errors.default_error_messages[: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 < AntMapper::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)

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

Raises:

  • (ArgumentError) 


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# File 'lib/ant_mapper/validations.rb', line 530

def validates_inclusion_of(*attr_names)
  configuration = { :message => AntMapper::Errors.default_error_messages[: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

class Person < AntMapper::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 (maximum 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)

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.



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# File 'lib/ant_mapper/validations.rb', line 427

def validates_length_of(*attrs)
  # Merge given options with defaults.
  options = {
    :too_long     => AntMapper::Errors.default_error_messages[:too_long],
    :too_short    => AntMapper::Errors.default_error_messages[:too_short],
    :wrong_length => AntMapper::Errors.default_error_messages[:wrong_length]
  }.merge(DEFAULT_VALIDATION_OPTIONS)
  options.update(attrs.pop.symbolize_keys) if attrs.last.is_a?(Hash)

  # Ensure that one and only one range option is specified.
  range_options = ALL_RANGE_OPTIONS & options.keys
  case range_options.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 = range_options.first
  option_value = options[range_options.first]

  case option
    when :within, :in
      raise ArgumentError, ":#{option} must be a Range" unless option_value.is_a?(Range)

      too_short = options[:too_short] % option_value.begin
      too_long  = options[:too_long]  % option_value.end

      validates_each(attrs, options) do |record, attr, value|
        if value.nil? or value.split(//).size < option_value.begin
          record.errors.add(attr, too_short)
        elsif value.split(//).size > option_value.end
          record.errors.add(attr, too_long)
        end
      end
    when :is, :minimum, :maximum
      raise ArgumentError, ":#{option} must be a nonnegative Integer" unless option_value.is_a?(Integer) and option_value >= 0

      # Declare different validations per option.
      validity_checks = { :is => "==", :minimum => ">=", :maximum => "<=" }
      message_options = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long }

      message = (options[:message] || options[message_options[option]]) % option_value

      validates_each(attrs, options) do |record, attr, value|
        if value.kind_of?(String)
          record.errors.add(attr, message) unless !value.nil? and value.split(//).size.method(validity_checks[option])[option_value]
        else
          record.errors.add(attr, message) unless !value.nil? and value.size.method(validity_checks[option])[option_value]
        end
      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 /\A[+\-]?\d+\Z/ (if integer is set to true).

class Person < AntMapper::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 columns empty strings are converted to nil

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.



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# File 'lib/ant_mapper/validations.rb', line 587

def validates_numericality_of(*attr_names)
  configuration = { :message => AntMapper::Errors.default_error_messages[: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 =~ /\A[+-]?\d+\Z/
    end
  else
    validates_each(attr_names,configuration) do |record, attr_name,value|
     next if configuration[:allow_nil] and record.send("#{attr_name}_before_type_cast").nil?
      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 not blank (as defined by Object#blank?). Happens by default on save. Example:

class Person < AntMapper::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

Configuration options:

  • message - A custom error message (default is: “can’t be blank”).

  • on - Specifies when this validation is active (default is :save, other options :create, :update).

  • if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

  • unless - Specifies a method, proc or string to call to determine if the validation should not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The method, proc or string should return or evaluate to a true or false value.



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# File 'lib/ant_mapper/validations.rb', line 389

def validates_presence_of(*attr_names)
  configuration = { :message => AntMapper::Errors.default_error_messages[:blank], :on => :save }
  configuration.update(attr_names.extract_options!)

  # can't use validates_each here, because it cannot cope with nonexistent attributes,
  # while errors.add_on_empty can
  send(validation_method(configuration[:on]), configuration) do |record|
    record.errors.add_on_blank(attr_names, configuration[:message])
  end
end