Updating/destroying EmbeddedDocuments in MongoMapper - mongomapper

Question

I can't seem to figure out how to update or destroy EmbeddedDocuments in MongoMapper. Through Googling I've seen different methods like delete_if {} and others, but none seem to work for me semantically. Is there anything built-in to MongoMapper to help with this?
class Schedule
include MongoMapper::Document
key :name, String
key :description, String
key :active, Boolean, :default => false
many :periods
validates_presence_of :name
def activate!
set({:active => true}, :active => false)
self.active = true
end
end
class Period
include MongoMapper::EmbeddedDocument
key :number, Integer
key :text, String
key :start, Time
key :finish, Time
embedded_in :schedule
before_validation :number!
validates_presence_of :number
validates_presence_of :text
validates_presence_of :start
validates_presence_of :finish
validates_format_of :start, :with => /^(2[0-3]|[01]?[0-9]):([0-5]?[0-9])$/
validates_format_of :finish, :with => /^(2[0-3]|[01]?[0-9]):([0-5]?[0-9])$/
def number!
unless self.number
number = schedule.periods.count + 1
end
end
end

Answer 1

The follow test shows examples on how to update and remove embedded documents in two ways:
(1) via Ruby using standard Array accessors and methods, and
(2) via Mongo (MongoMapper / MongoDB) for update and removal of embedded documents on the DB server
References:
http://www.ruby-doc.org/core-1.9.3/Array.html#method-i-delete_if
http://mongomapper.com/documentation/plugins/modifiers.html#set
http://www.mongodb.org/display/DOCS/Updating#Updating-%24set
Note that Hash keys containing '.' require use of the old ( => ) syntax. Hope that this helps.
test/unit/period_test.rb
require 'test_helper'
def ppp(obj)
puts obj.inspect.gsub(/(, |\[)#/, "\\1\n #")
end
class PeriodTest < ActiveSupport::TestCase
def setup
Schedule.delete_all
#today = Time.now.midnight
end
test "update and remove embedded documents" do
schedule = Schedule.create(name: 'George')
assert_equal(1, Schedule.count)
schedule.periods << Period.new(number: 1, text: 'period 1', start: #today + 8.hours, finish: #today + 9.hours)
schedule.periods << Period.new(number: 2, text: 'period 2', start: #today + 9.hours, finish: #today + 10.hours)
schedule.periods << Period.new(number: 3, text: 'period 3', start: #today + 10.hours, finish: #today + 11.hours)
schedule.periods.last.finish = #today + 12.hours #update in Ruby
schedule.save
assert_equal(1, Schedule.count)
puts "schedule with three periods --------"
ppp Schedule.first
schedule.periods.delete_if {|period| period.text == 'period 2'} #remove in Ruby
schedule.save
puts "schedule after removing period 2 in Ruby --------"
ppp Schedule.first
Schedule.set( {name: 'George', 'periods.text' => 'period 1'}, {'periods.$.finish' => #today + 10.hours} ) #update embedded document in MongoDB
puts "schedule after updatting period 1 via Mongo --------"
ppp Schedule.first
Schedule.pull( {name: 'George'}, { periods: { text: 'period 1'} } ) #remove embedded document in MongoDB
puts "schedule after pulling period 1 via Mongo --------"
ppp Schedule.first
end
end
output
Run options: --name=test_update_and_remove_embedded_documents
# Running tests:
schedule with three periods --------
#<Schedule _id: BSON::ObjectId('4ff732e77f11ba6fe9000001'), active: false, name: "George", periods: [
#<Period _id: BSON::ObjectId('4ff732e77f11ba6fe9000002'), finish: Fri, 06 Jul 2012 13:00:00 UTC +00:00, number: 1, start: Fri, 06 Jul 2012 12:00:00 UTC +00:00, text: "period 1">,
#<Period _id: BSON::ObjectId('4ff732e77f11ba6fe9000003'), finish: Fri, 06 Jul 2012 14:00:00 UTC +00:00, number: 2, start: Fri, 06 Jul 2012 13:00:00 UTC +00:00, text: "period 2">,
#<Period _id: BSON::ObjectId('4ff732e77f11ba6fe9000004'), finish: Fri, 06 Jul 2012 16:00:00 UTC +00:00, number: 3, start: Fri, 06 Jul 2012 14:00:00 UTC +00:00, text: "period 3">]>
schedule after removing period 2 in Ruby --------
#<Schedule _id: BSON::ObjectId('4ff732e77f11ba6fe9000001'), active: false, name: "George", periods: [
#<Period _id: BSON::ObjectId('4ff732e77f11ba6fe9000002'), finish: Fri, 06 Jul 2012 13:00:00 UTC +00:00, number: 1, start: Fri, 06 Jul 2012 12:00:00 UTC +00:00, text: "period 1">,
#<Period _id: BSON::ObjectId('4ff732e77f11ba6fe9000004'), finish: Fri, 06 Jul 2012 16:00:00 UTC +00:00, number: 3, start: Fri, 06 Jul 2012 14:00:00 UTC +00:00, text: "period 3">]>
schedule after updatting period 1 via Mongo --------
#<Schedule _id: BSON::ObjectId('4ff732e77f11ba6fe9000001'), active: false, name: "George", periods: [
#<Period _id: BSON::ObjectId('4ff732e77f11ba6fe9000002'), finish: Fri, 06 Jul 2012 14:00:00 UTC +00:00, number: 1, start: Fri, 06 Jul 2012 12:00:00 UTC +00:00, text: "period 1">,
#<Period _id: BSON::ObjectId('4ff732e77f11ba6fe9000004'), finish: Fri, 06 Jul 2012 16:00:00 UTC +00:00, number: 3, start: Fri, 06 Jul 2012 14:00:00 UTC +00:00, text: "period 3">]>
schedule after pulling period 1 via Mongo --------
#<Schedule _id: BSON::ObjectId('4ff732e77f11ba6fe9000001'), active: false, name: "George", periods: [
#<Period _id: BSON::ObjectId('4ff732e77f11ba6fe9000004'), finish: Fri, 06 Jul 2012 16:00:00 UTC +00:00, number: 3, start: Fri, 06 Jul 2012 14:00:00 UTC +00:00, text: "period 3">]>
.
Finished tests in 0.038952s, 25.6726 tests/s, 51.3452 assertions/s.
1 tests, 2 assertions, 0 failures, 0 errors, 0 skips