Module: ActsAsIntegerInfinitable::ClassMethods

Defined in:
lib/acts_as_integer_infinitable.rb

Instance Method Summary collapse

Instance Method Details

#acts_as_integer_infinitable(fields, options = {}) ⇒ Object

Allows the fields to store an Infinity value.

Overrides the setter and getter of those fields in order to capture and return Infinity when appropiate.

Then you can use it as any other value and get the desired result, like decrementing, incrementing, comparing with <, >, ==, etc.

Example:

class LibrarySubscription < ActiveRecord::Base
  acts_as_integer_infinitable [:available_books]

  def rent_book
    # Do other things...
    self.available_books -= 1
    save
  end
end

> simple_subscription = LibrarySubscription.new(available_books: 5)
> simple_subscription.available_books
=> 5
> simple_subscription.rent_book
> simple_subscription.available_books
=> 4

> complete_subscription = LibrarySubscription.new(available_books: Float::INFINITY)
> long_subscription.available_books
=> Infinity
> long_subscription.rent_book
> long_subscription.available_books
=> Infinity

Parameters

  • fields - An Array with the fields that will be infinitable. They have to be integers in the database.

Options

  • :infinity_value - The value that will be converted to Infinity. Default: -1. Another popular value is ‘nil`.



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# File 'lib/acts_as_integer_infinitable.rb', line 48

def acts_as_integer_infinitable(fields, options = {})
  options[:infinity_value] = -1 unless options.key? :infinity_value

  fields.each do |field|
    define_method("#{field}=") do |value|
      int_value = value == Float::INFINITY ? options[:infinity_value] : value
      write_attribute(field, int_value)
    end

    define_method("#{field}") do
      value = read_attribute(field)
      value == options[:infinity_value] ? Float::INFINITY : value
    end
  end
end