Having trouble in updating join model extra attributes in has_many through association - Rails

Question

I am still a learner of Rails, and am making a simulation game of Google Adwords for training usage. Inside the game (I may only explain the related part of this question), I have three models, Adgroup (called KeywordAdgroup in my code), Keyword, AdgroupKeyword , and also a Game model that has a game_id in it.

The relationship of the three models is a has_many through: assciation, which Adgroup has many Keywords through AdgroupKeyword, and Keyword has many Adgroups through AdgroupKeyword.

Now, I want to adopt a logic that every Keyword could only be added into single Adgroup of a particular game. So I added an extra attribute game_id to the join model - AdgroupKeyword, and adopt validates_uniqueness_of :keyword_id, scope: :game_id into this model.

However, I found that with the similar code, I can validate the uniqueness in Create using .save method, but I can't validate the uniqueness in Update using .update(params) method.

The major problem is that, with the similar code in create and update , the create one can save the game_id to the join model(AdgroupKeyword), where update(params) didn't save the game_id to the join model, which in the console, I can see that update didn't insert game_id into the record.

It will become something like game_id: nil :

#<AdgroupKeyword id: 180, keyword_id: 9, created_at: "2016-12-04 11:12:00", updated_at: "2016-12-04 11:12:00", keyword_adgroup_id: 77, game_id: nil>

But the save method did insert the game_id, which game_id is not nil when inserted using the save method. Something like

#<AdgroupKeyword id: 174, keyword_id: 10, created_at: "2016-12-04 10:23:50", updated_at: "2016-12-04 10:23:50", keyword_adgroup_id: 77, game_id: 3>

The following is my code:

keyword_adgroup.rb (the model of Adgroup)

class KeywordAdgroup < ApplicationRecord
  belongs_to :keyword_campaign

  has_many :adgroup_keywords, inverse_of: :keyword_adgroup, dependent: :destroy
  has_many :keywords, through: :adgroup_keywords, source: :keyword
  accepts_nested_attributes_for :adgroup_keywords, allow_destroy: true

  ...

  accepts_nested_attributes_for :keywords

  ...

  ...
end

keyword.rb

class Keyword < ApplicationRecord
  ...

  ...

  has_many :keyword_adgroups, through: :adgroup_keywords
  has_many :adgroup_keywords

  ...
end

adgroup_keyword.rb (the join model)

class AdgroupKeyword < ApplicationRecord
  belongs_to :keyword_adgroup
  belongs_to :keyword

  validates_uniqueness_of :keyword_id, scope: :game_id

end

And majorly the relation would be built in the Adgroup controller.

adgroups_controller.rb

class Adwords::AdgroupsController < AdwordsController

  def index
    ...
  end

  def new
    @adgroup = KeywordAdgroup.new
  end

  def create
    @campaign = current_user.game.keyword_campaigns.find(params[:keyword_campaign_id])
    @adgroup = @campaign.keyword_adgroups.build(adgroup_params)
    @adgroup.game_id = @campaign.game_id
    @adgroup.adgroup_keywords.each do |join|
      join.game_id = @adgroup.game_id    
    end

    if @adgroup.save
      redirect_to new_adwords_ad_path(keyword_adgroup_id: @adgroup.id)
    else
      render :new
    end
  end

  def edit
    @adgroup = KeywordAdgroup.find(params[:id])
  end

  def update
    @adgroup = KeywordAdgroup.find(params[:id])
    @campaign = @adgroup.keyword_campaign
    @adgroup.game_id = @campaign.game_id
    @joins = @adgroup.adgroup_keywords
    @joins.each do |join|
      join.game_id = @adgroup.game_id  
    end 
    if @adgroup.update(adgroup_params)

      redirect_to adwords_adgroups_path, notice: "Adgroup updated"
    else
      render :edit
    end
  end

  ...

  private
  def adgroup_params
    params.require(:keyword_adgroup).permit(:name, :activate, :bid, keyword_ids: [], adgroup_keywords_attributes: [:game_id])
  end

end

When choosing duplicate keyword in the same game in whatever adgroup, in "create", it will come to a rollback; in "update", it will just update the record with game_id: nil .

FYI, I am using Ruby 2.3.0, Rails 5.0.0, and using simpleform for creating and updating adgroup.

I know its a little bit messy, sorry about that and thanks for reading my words. Appreciate any suggestions. Have already spent several hours to fix it but really hopeless after a lot of different methods. Thought that it was some conceptual problem that I haven't figured out.

---

Updated Information

While checking the console, in "Create" method, it will come to:

  AdgroupKeyword Exists (0.4ms)  SELECT  1 AS one FROM "adgroup_keywords" WHERE "adgroup_keywords"."keyword_id" = ? AND "adgroup_keywords"."game_id" = ? LIMIT ?  [["keyword_id", 14], ["game_id", 3], ["LIMIT", 1]]
  Keyword Exists (0.3ms)  SELECT  1 AS one FROM "keywords" WHERE "keywords"."keyword" = ? AND ("keywords"."id" != ?) LIMIT ?  [["keyword", "Japan local trip"], ["id", 14], ["LIMIT", 1]]
  KeywordAdgroup Exists (0.2ms)  SELECT  1 AS one FROM "keyword_adgroups" WHERE "keyword_adgroups"."name" = ? AND "keyword_adgroups"."keyword_campaign_id" = ? LIMIT ?  [["name", "3"], ["keyword_campaign_id", 36], ["LIMIT", 1]]
  SQL (2.3ms)  INSERT INTO "keyword_adgroups" ("name", "activate", "bid", "created_at", "updated_at", "keyword_campaign_id", "game_id") VALUES (?, ?, ?, ?, ?, ?, ?)  [["name", "3"], ["activate", true], ["bid", #<BigDecimal:7fcaac52c320,'0.1E1',9(18)>], ["created_at", 2016-12-04 13:10:19 UTC], ["updated_at", 2016-12-04 13:10:19 UTC], ["keyword_campaign_id", 36], ["game_id", 3]]
  SQL (0.2ms)  INSERT INTO "adgroup_keywords" ("keyword_id", "created_at", "updated_at", "keyword_adgroup_id", "game_id") VALUES (?, ?, ?, ?, ?)  [["keyword_id", 14], ["created_at", 2016-12-04 13:10:19 UTC], ["updated_at", 2016-12-04 13:10:19 UTC], ["keyword_adgroup_id", 84], ["game_id", 3]]
  AdgroupKeyword Exists (0.3ms)  SELECT  1 AS one FROM "adgroup_keywords" WHERE "adgroup_keywords"."keyword_id" = ? AND ("adgroup_keywords"."id" != ?) AND "adgroup_keywords"."game_id" = ? LIMIT ?  [["keyword_id", 14], ["id", 187], ["game_id", 3], ["LIMIT", 1]]

In "Update" method, it will come to:

  AdgroupKeyword Exists (0.2ms)  SELECT  1 AS one FROM "adgroup_keywords" WHERE "adgroup_keywords"."keyword_id" = ? AND "adgroup_keywords"."game_id" IS NULL LIMIT ?  [["keyword_id", 17], ["LIMIT", 1]]
  SQL (2.0ms)  INSERT INTO "adgroup_keywords" ("keyword_id", "created_at", "updated_at", "keyword_adgroup_id") VALUES (?, ?, ?, ?)  [["keyword_id", 17], ["created_at", 2016-12-04 13:07:03 UTC], ["updated_at", 2016-12-04 13:07:03 UTC], ["keyword_adgroup_id", 82]]
  AdgroupKeyword Exists (0.2ms)  SELECT  1 AS one FROM "adgroup_keywords" WHERE "adgroup_keywords"."keyword_id" = ? AND ("adgroup_keywords"."id" != ?) AND "adgroup_keywords"."game_id" = ? LIMIT ?  [["keyword_id", 11], ["id", 185], ["game_id", 3], ["LIMIT", 1]]

Answer 1

Can you try to run this block after the #update call (inside the if block)?

@adgroup.reload

@adgroup.adgroup_keywords.each do |join|
  join.update(:game_id, @adgroup.game_id)
end