Module: ExpiryCalculator::Logic

Included in:
ExpiryCalculator
Defined in:
lib/expiry_calculator/logic.rb

Instance Method Summary collapse

Instance Method Details

#calculate(record, record_attr = nil) ⇒ Object

A function to calculate the expiration from a given date.

Parameters:

record

Date|DateTime|String|ApplicationRecord: field of date and time to caluclate expiry for. Can be activerecord model containing a date field.

record_attr

symbol|string The date attribute field in case of active record model is passed in first arguemtn. Default to nil.

Returns:

The remaining days till the expiry, or zero if it already past.

Note:

ref# for AR special check case: github.com/rails/rails/blob/04cda1848cb847c2bdad0bfc12160dc8d5547775/activerecord/lib/active_record/core.rb#L135



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# File 'lib/expiry_calculator/logic.rb', line 19

def calculate record, record_attr = nil
  expiry_date = case record
  when DateTime
    record
  when Date
    record
  when String
    DateTime.parse(record)
  when ->(r) { defined?(ActiveRecord::Base) && r.is_a?(ActiveRecord::Base) }
    record[record_attr.to_sym]
  else
    raise ArgumentError, "record type not supported."
  end
  days = (Date.today..expiry_date).count
  days.zero? ? 0 : days - 1
end