Rails has_one association expected Model got String

Question

Having the following associations between 3 models:

workout.rb

class Workout < ActiveRecord::Base
  has_and_belongs_to_many :workout_sets, :join_table => :workout_sessions
  belongs_to :warmup, :class_name => :WorkoutStep, :foreign_key => "workout_step_id"
  accepts_nested_attributes_for :workout_sets, allow_destroy: true
  accepts_nested_attributes_for :warmup, allow_destroy: true
end

workout_set.rb

class WorkoutSet < ActiveRecord::Base
  has_and_belongs_to_many :workout_steps, :join_table => :sets_steps, dependent: :destroy
  has_and_belongs_to_many :workouts, :join_table => :workout_sessions
  accepts_nested_attributes_for :workout_steps, allow_destroy: true

  has_one :intro_video_usage, class_name: 'VideoUsage::Intro', as: :parent, dependent: :destroy
  has_one :intro_video, through: :intro_video_usage, source: :video

  accepts_nested_attributes_for :intro_video

  has_one :get_ready_video_usage, class_name: 'VideoUsage::GetReady', as: :parent, dependent: :destroy
  has_one :get_ready_video, through: :get_ready_video_usage, source: :video

  has_one :congrats_video_usage, class_name: 'VideoUsage::Congratulations', as: :parent, dependent: :destroy
  has_one :congrats_video, through: :congrats_video_usage, source: :video
end

and

workout_step.rb

class WorkoutStep < ActiveRecord::Base
  has_and_belongs_to_many :workout_sets, :join_table => :sets_steps
  has_many :main_video_usage, class_name: 'VideoUsage::Main', as: :parent
  has_many :main_videos, through: :main_video_usage, source: :video
  accepts_nested_attributes_for :main_videos
end

And using simple_form and cocoon to handle nested models creation on the top level model (Workout) I'm having troubles building the form for sets and steps - more concise, when associating a workout_set with an intro_video (and whitelisting the params) I'm having the following error:

Video(#70285207226600) expected, got String(#70285080848240)

The params object after sending looks like this:

"workout"=>{"title"=>"",
 "workout_sets_attributes"=>{"0"=>{"_destroy"=>"false",
 "intro_video"=>"70",
 "title"=>""}}},
 "image"=>"",
 "sound_logo"=>"",
 "intro_video"=>"",
 "commit"=>"Create workout"}

Thanks in advance.

Answer 1

Your parameters are passing a string ("70") to intro_video= but association accessors like that expect you to pass an actual instance of the associated class (in this case Video).

You should instead be assigning to intro_video_id. The accessor will convert the string to an integer for you.