Class: Predicates::Number

Inherits:
Base
  • Object
show all
Defined in:
lib/predicates/number.rb

Overview

Describes an attribute as a number. You may specify boundaries for the number (min, max, or both), and also specify whether it must be an integer.

Options

  • :integer [boolean, default: false] - if the number is an integer (or float/decimal)

  • :above [integer, float] - when the number has a minimum

  • :below [integer, float] - when the number has a maximum

  • :range [range] - when the number has a minimum and a maximum

  • :inclusive [boolean, default: false] - if your maximum or minimum is also an allowed value. Does not work with :range.

  • :at_least [integer, float] - an easy way to say :above and :inclusive

  • :no_more_than [integer, float] - an easy way to say :below and :inclusive

Examples

field_is_a_number :integer => true
field_is_a_number :range => 1..5, :integer => true
field_is_a_number :above => 4.5
field_is_a_number :below => 4.5, :inclusive => true

Instance Attribute Summary collapse

Attributes inherited from Base

#full_message, #or_empty, #validate_if, #validate_on

Instance Method Summary collapse

Methods inherited from Base

#allow_empty?, #error, #initialize, #normalize, #to_human

Constructor Details

This class inherits a constructor from Predicates::Base

Instance Attribute Details

#above ⇒ Object

when the number has a minimum value, but no maximum



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# File 'lib/predicates/number.rb', line 22

def above
  @above
end

#below ⇒ Object

when the number has a maximum value, but no minimum



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# File 'lib/predicates/number.rb', line 25

def below
  @below
end

#inclusive ⇒ Object

meant to be used with :above and :below, when you want the endpoint to be inclusive. with the :range option you can just specify inclusion using the standard Ruby range syntax.



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# File 'lib/predicates/number.rb', line 32

def inclusive
  @inclusive
end

#integer ⇒ Object

whether to require an integer value



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# File 'lib/predicates/number.rb', line 19

def integer
  @integer
end

#range ⇒ Object

when the number has both a maximum and a minimum value



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# File 'lib/predicates/number.rb', line 28

def range
  @range
end

Instance Method Details

#at_least=(val) ⇒ Object 



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# File 'lib/predicates/number.rb', line 34

def at_least=(val)
  self.above = val
  self.inclusive = true
end

#error_binds ⇒ Object 



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# File 'lib/predicates/number.rb', line 48

def error_binds
  self.range ?
    {:min => self.range.first, :max => self.range.last} :
    {:min => self.above, :max => self.below}
end

#error_message ⇒ Object 



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# File 'lib/predicates/number.rb', line 44

def error_message
  @error_message || range_description
end

#no_more_than=(val) ⇒ Object 



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# File 'lib/predicates/number.rb', line 39

def no_more_than=(val)
  self.below = val
  self.inclusive = true
end

#validate(value, record) ⇒ Object 



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# File 'lib/predicates/number.rb', line 54

def validate(value, record)
  # check data type
  valid = if self.integer
      # if it must be an integer, do a regexp check for digits only
      value.to_s.match(/\A[+-]?[0-9]+\Z/) unless value.is_a? Hash or value.is_a? Array
    else
      # if it can also be a float or decimal, then try a conversion
      begin
        Kernel.Float(value)
        true
      rescue ArgumentError, TypeError
        false
      end
    end

  # if it's the right data type, then also check boundaries
  valid &&= if self.range
      self.range.include? value
    elsif self.above
      operator = self.inclusive ? :>= : :>
      value.send operator, self.above
    elsif self.below
      operator = self.inclusive ? :<= : :<
      value.send operator, self.below
    else
      true
    end

  valid
end