Module: DateFlag

Defined in:
lib/date_flag.rb

Constant Summary collapse

VERSION = 
File.read(File.expand_path('../VERSION', File.dirname(__FILE__))).chomp

Instance Method Summary collapse

Instance Method Details

#date_flag(field, options = { }) ⇒ Object

Usage:

class MyModel < ActiveRecord::Base

date_flag :flagged_at, action: :flag

end

m = MyModel.new m.flagged? # => false m.flag! # Assigns flag_at to current time m.flag = true # Same as flag! m.flagged? # => true



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# File 'lib/date_flag.rb', line 16

def date_flag(field, options =  { })
  name = (options[:name] ? options[:name] : field.to_s.sub(/_at$/, '')).to_sym
  action = (options[:action] ? options[:action] : name).to_sym

  scope_name =
    case (options[:scope])
    when nil, true
      name
    when false
      false
    else
      options[:scope].to_s.to_sym
    end

  case (scope_name)
  when false, nil
    # Skip this operation
  when :send, :id
    # TODO: Invalid names, should raise exception or warning
  else
    scope scope_name, lambda { |*flag|
      case (flag.first)
      when false
        where(field => nil)
      when true, nil
        where.not(field => nil)
      else
        # FIX: Escape properly for Postgres/MySQL
        where([ "#{field}<=?", flag.first ])
      end
    }
  end

  if (options[:inverse])
    scope options[:inverse], lambda { |*flag|
      case (flag.first)
      when false
        where.not(field => nil)
      when true, nil
        where(field => nil)
      else
        # FIX: Escape properly for Postgres/MySQL
        where([ "#{field}>?", flag.first ])
      end
    }
  end

  if (inverse_action = options[:inverse_action] || options[:inverse])
    define_method(:"#{inverse_action}!") do
      write_attribute(field, nil)
      
      save!
    end
  end

  define_method(:"#{name}=") do |value|
    # The action= mutator method is used to manipulate the trigger time.
    # Values of nil, false, empty string, '0' or 0 are presumed to be
    # false and will nil out the time. A DateTime, Date or Time object
    # will be saved as-is, and anything else will just assign the current
    # time.

    case (value)
    when nil, false, '', '0', 0
      write_attribute(field, nil)
    when DateTime, Date, Time
      write_attribute(field, value)
    else
      !read_attribute(field) and write_attribute(field, Time.now)
    end
  end

  define_method(:"#{name}") do
    value = read_attribute(field)

    value ? (value <= Time.now) : false
  end

  define_method(:"#{name}?") do
    # The name? accessor method will return true if the date is defined
    # and is prior to the current time, or false otherwise.
    value = read_attribute(field)

    value ? (value <= Time.now) : false
  end

  define_method(:"#{action}!") do |*at_time|
    # The name! method is used to set the trigger time. If the time is
    # already defined and is in the past, then the time is left unchanged.
    # If it is undefined or in the future, then the current time is
    # substituted.

    value = read_attribute(field)

    at_time =
      case (at_time.first)
      when false
        nil
      else
        at_time.first || value || Time.now
      end

    return if (at_time == value)

    write_attribute(field, at_time)
    save!
  end
end