Mongoid self referencing with accepts_nested_attributes_for - ruby-on-rails

Question

Model:
class Plan
include Mongoid::Document
# Fields
field :name, type: String
# Relationships
references_many :sub_plans,
:autosave => true,
:class_name => 'Plan',
:inverse_class_name => 'Plan',
:inverse_of => :super_plans
references_many :super_plans,
:class_name => 'Plan',
:inverse_class_name => 'Plan',
:inverse_of => :sub_plans
accepts_nested_attributes_for :sub_plans
# Validations
validates_presence_of :name
end
Test:
describe Plan do
it "should always have a name" do
plan = Plan.new
plan.save.should == false
plan[:name] = "World Domination"
plan.save.should == true
end
it "should allow nested plan creation" do
plan = Plan.new(:name => "World Domination", :sub_plans_attributes => {
:name => "Get $50b",
:sub_plans_attributes => {
:name => "Invent"
}
});
plan.sub_plans.count.should == 1
plan.sub_plans.first.name.should == "Get $50b"
plan.sub_plans.first.sub_plans.count.should == 1
plan.sub_plans.first.sub_plans.first.name.should == "Invent"
end
end
Output with -b:
Running spec/models/plan_spec.rb
.F
Failures:
1) Plan should allow nested plan creation
Failure/Error: plan = Plan.new(:name => "World Domination", :sub_plans_attributes => {
TypeError:
can't convert Symbol into String
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/relations/builders/nested_attributes/many.rb:67:in `delete'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/relations/builders/nested_attributes/many.rb:67:in `destroyable?'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/relations/builders/nested_attributes/many.rb:103:in `process'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/relations/builders/nested_attributes/many.rb:30:in `block in build'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/relations/builders/nested_attributes/many.rb:26:in `each'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/relations/builders/nested_attributes/many.rb:26:in `build'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/nested_attributes.rb:47:in `block (3 levels) in accepts_nested_attributes_for'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/attributes.rb:193:in `_assigning'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/nested_attributes.rb:45:in `block (2 levels) in accepts_nested_attributes_for'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/attributes/processing.rb:111:in `block in process_nested'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/attributes/processing.rb:110:in `each_pair'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/attributes/processing.rb:110:in `process_nested'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/attributes/processing.rb:122:in `process_pending'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/attributes/processing.rb:29:in `process'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/document.rb:131:in `block in initialize'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/relations/builders.rb:47:in `_building'
# /usr/lib/ruby/gems/1.9.1/gems/mongoid-2.3.1/lib/mongoid/document.rb:127:in `initialize'
# ./spec/models/plan_spec.rb:11:in `new'
# ./spec/models/plan_spec.rb:11:in `block (2 levels) in <top (required)>'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/example.rb:48:in `instance_eval'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/example.rb:48:in `block in run'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/example.rb:107:in `with_around_hooks'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/example.rb:45:in `run'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/example_group.rb:294:in `block in run_examples'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/example_group.rb:290:in `map'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/example_group.rb:290:in `run_examples'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/example_group.rb:262:in `run'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/command_line.rb:24:in `block (2 levels) in run'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/command_line.rb:24:in `map'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/command_line.rb:24:in `block in run'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/reporter.rb:12:in `report'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/core/command_line.rb:21:in `run'
# /usr/lib/ruby/gems/1.9.1/gems/rspec-core-2.6.4/lib/rspec/monkey/spork/test_framework/rspec.rb:5:in `run_tests'
# /usr/lib/ruby/gems/1.9.1/gems/spork-0.9.0.rc9/lib/spork/run_strategy/forking.rb:13:in `block in run'
# /usr/lib/ruby/gems/1.9.1/gems/spork-0.9.0.rc9/lib/spork/forker.rb:21:in `block in initialize'
# /usr/lib/ruby/gems/1.9.1/gems/spork-0.9.0.rc9/lib/spork/forker.rb:18:in `fork'
# /usr/lib/ruby/gems/1.9.1/gems/spork-0.9.0.rc9/lib/spork/forker.rb:18:in `initialize'
# /usr/lib/ruby/gems/1.9.1/gems/spork-0.9.0.rc9/lib/spork/run_strategy/forking.rb:9:in `new'
# /usr/lib/ruby/gems/1.9.1/gems/spork-0.9.0.rc9/lib/spork/run_strategy/forking.rb:9:in `run'
# /usr/lib/ruby/gems/1.9.1/gems/spork-0.9.0.rc9/lib/spork/server.rb:48:in `run'
# /usr/lib/ruby/1.9.1/drb/drb.rb:1558:in `perform_without_block'
# /usr/lib/ruby/1.9.1/drb/drb.rb:1518:in `perform'
# /usr/lib/ruby/1.9.1/drb/drb.rb:1592:in `block (2 levels) in main_loop'
# /usr/lib/ruby/1.9.1/drb/drb.rb:1588:in `loop'
# /usr/lib/ruby/1.9.1/drb/drb.rb:1588:in `block in main_loop'
Finished in 0.00917 seconds
2 examples, 1 failure
Failed examples:
rspec ./spec/models/plan_spec.rb:10 # Plan should allow nested plan creation
Why am I getting this error, and how can I get my many-many self reference working? I'm using Mongoid version 2.3.1 and Rails version 3.1.1. Thanks

Answer 1

After several hours spent trying several different combinations and finally giving up and sleeping on it, I have finally got it to work! Model:
class Plan
include Mongoid::Document
# Fields
field :name, type: String
# Relationships
has_and_belongs_to_many :subplans, :inverse_of => :parents, :class_name => 'Plan', :autosave => true
has_and_belongs_to_many :parents, :inverse_of => :subplans, :class_name => 'Plan', :autosave => true
accepts_nested_attributes_for :subplans
# Validations
validates_presence_of :name
end
Tests:
describe Plan do
it "should always have a name" do
plan = Plan.new
plan.save.should == false
plan[:name] = "World Domination"
plan.save.should == true
end
it "should have a nested relationship" do
root = Plan.create name: "Parent Plan"
child1 = root.subplans.create name: 'Child Plan #1'
child2 = Plan.create name: "Child Plan #2"
root.subplans << child2
root.subplans.size.should == 2
child1.parents.size.should == 1
child1.parents.first.should == root
child2.parents.size.should == 1
child2.parents.first.should == root
end
it "should accept nested attributes for subplans" do
plan = Plan.new :name => "root",
:subplans_attributes => [{:name => "child"}]
plan.save; plan.reload
plan.subplans.size.should == 1
plan.subplans.first.name.should == "child"
end
end