Code For: Partially Solving The Date Parsing Defficiency Of Rails 3 And Mongoid

1-model-workaround.rb

class SomeModel
  include Mongoid::Document

  field :date, :type => Date
  validates_presence_of :date

  def date=(value)
    begin
      date_parsed = value.to_date
      write_attribute :date, date_parsed
      @bad_date = nil
    rescue
      write_attribute :date, nil
      @bad_date = value
    end
  end

  def date
    return @bad_date if @bad_date
    read_attribute :date
  end

end

2-datefield-concern.rb

module Mongoid
  module DateField
    extend ActiveSupport::Concern

    included do
      validates_with Mongoid::DateFieldValidator
    end

    module ClassMethods
      def date_field(name)
        self.class_eval(<<-EOL, __FILE__, __LINE__)
          field :#{name}, :type => Date

          def #{name}=(value)
            set_date_field_value :#{name}, value
          end

          def #{name}
            get_date_field_value :#{name}
          end
        EOL
      end
    end

    def date_fields
      @date_fields ||= {}
    end

    def set_date_field_value(name, value)
      field = get_date_field name
      begin
        parsed_value = value.to_date
        field[:broken_value] = nil
        field[:valid] = true
      rescue
        parsed_value = nil
        field[:broken_value] = value
        field[:valid] = false
      end
      write_attribute name, parsed_value
    end

    def get_date_field_value(name)
      field = get_date_field name
      if !field.key?(:valid) or field[:valid]
        raw_value = read_attribute(name)
        value = raw_value.to_date if raw_value
      else
        value = field[:broken_value]
      end
      value
    end

    def get_date_field(name)
      if date_fields.key? name
        field = date_fields[name]
      else
        field = {}
        date_fields[name] = field
      end
      field
    end

  end

  class DateFieldValidator < ActiveModel::Validator
    def validate(model)
      is_valid = true
      model.date_fields.each do |name, data|
        if !data[:valid]
          is_valid = false
          model.errors.add name, "must be a valid date: MM/DD/YYYY"
        end
      end
      is_valid
    end
  end
end

3-model-update.rb

class SomeModel
  include Mongoid::Document
  include Mongoid::DateField

  date_field :date
end

4-write_attributes-workaround.rb

med_data = params[:medication]
start_date = med_data[:start_date]
prescription_date = med_data[:prescription_date]

med_data.reject! {|k,v| [:start_date, :prescription_date].include? k.to_sym}

med = Medication.new med_data
med.start_date = start_date
med.prescription_date = prescription_date

med.save