Railsのモデルは、保存に失敗したが、エラーメッセージは表示されません

Question

I多対多の関係を介して通信し、次のRailsのモデルを持っている：

class Task < ApplicationRecord 
    belongs_to :case 
    has_many :task_actor_roles 
    has_many :task_artifacts 

    has_many :task_activities 
    has_many :activities, through: :task_activities 

    accepts_nested_attributes_for :task_activities 

    attr_accessor :tasks_attributes 
end 

...

class TaskActivity < ApplicationRecord 
    belongs_to :task 
    belongs_to :activity 
    belongs_to :instantiation_operator 
end 

...

class Activity < ApplicationRecord 
    belongs_to :software_process 
    has_many :artifacts, :dependent => :destroy 
    belongs_to :activity_role 
    has_many :task_activities 
    has_many :tasks, through: :task_activities 
end 

私は、新しいタスクフォームで複数選択フィールドを追加するために、ネストされた形の宝石を使用しています。ここ はフォームを生成するコードの一部です：

<%= nested_form_for(task, url: {action: action}) do |f| %> 
    <%= f.label :activities %> 
    <%= f.fields_for :task_activities do |task_activity| %> 
    <%= task_activity.select(:activity_id,@activities.collect { |p| [p.name, p.id] }) %> 
    <%= task_activity.hidden_field :instantiation_operator_id, :value => @operator.id %> 
    <%= task_activity.link_to_remove "Remove this activity" %> 
    <% end %> 
    <p><%= f.link_to_add "Add an activity", :task_activities %></p> 
    <div class="field"> 
    <%= f.label :name %> 
    <%= f.text_field :name %> 
    </div> 
    <%= f.submit %> 
<%= end %> 

それはしかし、それは何も表示されません、検証エラーを示すだろうかのように私はデータページのリロードを送信します。私はそれが何の問題もなく保存し、フォーム内のネストされた属性を持つ行をコメントアウトすると

Started POST "/tasks/create_group" for 127.0.0.1 at 2016-11-24 21:51:40 -0200 
Processing by TasksController#create_group as HTML 
    Parameters: {"utf8"=>"✓", "authenticity_token"=>"[FILTERED]", "task"=>{"case_id"=>"1", "task_activities_attributes"=>{"1480031490821"=>{"activity_id"=>"11", "instantiation_operator_id"=>"6", "_destroy"=>"false"}, "1480031492604"=>{"activity_id"=>"14", "instantiation_operator_id"=>"6", "_destroy"=>"false"}}, "name"=>"Doris Woodard", "description"=>"Aperiam impedit aut fugit amet anim perspiciatis mollit", "priority"=>"Dolores explicabo Ipsum dolorem sit in cum iste enim nisi sint sed ratione odio", "category"=>"Eos cumque consequuntur iste est enim minim beatae et dolores mollit id quis ut occaecat laboriosam molestiae aut ipsa nulla", "status"=>"Veritatis qui id quaerat distinctio Blanditiis odio sit quisquam vel provident optio consectetur", "startDate"=>"25-Feb-2001", "comments"=>"Voluptatem eiusmod amet in ut", "TTC"=>"43"}, "task_activity"=>{"instantiation_operator_id"=>"6"}, "task_actor_role"=>{"task_role_id"=>"2", "task_actor_id"=>"3"}, "commit"=>"Create Task"} 
    (0.1ms) BEGIN 
    Case Load (0.3ms) SELECT "cases".* FROM "cases" WHERE "cases"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]] 
    TaskActor Load (0.4ms) SELECT "task_actors".* FROM "task_actors" WHERE "task_actors"."id" = $1 LIMIT $2 [["id", 3], ["LIMIT", 1]] 
    TaskRole Load (0.3ms) SELECT "task_roles".* FROM "task_roles" WHERE "task_roles"."id" = $1 LIMIT $2 [["id", 2], ["LIMIT", 1]] 
    Activity Load (0.2ms) SELECT "activities".* FROM "activities" WHERE "activities"."id" = $1 LIMIT $2 [["id", 11], ["LIMIT", 1]] 
    InstantiationOperator Load (0.4ms) SELECT "instantiation_operators".* FROM "instantiation_operators" WHERE "instantiation_operators"."id" = $1 LIMIT $2 [["id", 6], ["LIMIT", 1]] 
    Activity Load (0.4ms) SELECT "activities".* FROM "activities" WHERE "activities"."id" = $1 LIMIT $2 [["id", 14], ["LIMIT", 1]] 
    CACHE (0.0ms) SELECT "instantiation_operators".* FROM "instantiation_operators" WHERE "instantiation_operators"."id" = $1 LIMIT $2 [["id", 6], ["LIMIT", 1]] 
    (0.2ms) ROLLBACK 
    InstantiationOperator Load (0.2ms) SELECT "instantiation_operators".* FROM "instantiation_operators" WHERE "instantiation_operators"."name" = $1 LIMIT $2 [["name", "group"], ["LIMIT", 1]] 
    Case Load (0.3ms) SELECT "cases".* FROM "cases" WHERE "cases"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]] 
    Rendering tasks/group.html.erb within layouts/application 
    Project Load (0.2ms) SELECT "projects".* FROM "projects" WHERE "projects"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]] 
    SoftwareProcess Load (0.2ms) SELECT "software_processes".* FROM "software_processes" WHERE "software_processes"."id" = $1 LIMIT $2 [["id", 2], ["LIMIT", 1]] 
    TaskRole Load (0.3ms) SELECT "task_roles".* FROM "task_roles" 
    TaskActor Load (0.2ms) SELECT "task_actors".* FROM "task_actors" 
    Activity Load (0.2ms) SELECT "activities".* FROM "activities" 
    Rendered tasks/_form.html.erb (10.8ms) 
    Rendered tasks/group.html.erb within layouts/application (14.1ms) 
    User Load (0.7ms) SELECT "users".* FROM "users" WHERE "users"."remember_token" = $1 ORDER BY "users"."id" ASC LIMIT $2 [["remember_token", "e97f4b0c90c219f7223b805989eb25dbc6e2cae2"], ["LIMIT", 1]] 
Completed 200 OK in 220ms (Views: 150.4ms | ActiveRecord: 7.7ms) 

：

これは、端末のログがどのように見えるかです。問題は確かにそれにあります。

UPDATE

だから私は@taskを検査するbyebug使用：

@task.valid? 
    Case Load (0.4ms) SELECT "cases".* FROM "cases" WHERE "cases"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]] 
    TaskActor Load (0.2ms) SELECT "task_actors".* FROM "task_actors" WHERE "task_actors"."id" = $1 LIMIT $2 [["id", 3], ["LIMIT", 1]] 
    TaskRole Load (0.2ms) SELECT "task_roles".* FROM "task_roles" WHERE "task_roles"."id" = $1 LIMIT $2 [["id", 2], ["LIMIT", 1]] 
    Activity Load (0.3ms) SELECT "activities".* FROM "activities" WHERE "activities"."id" = $1 LIMIT $2 [["id", 2], ["LIMIT", 1]] 
    InstantiationOperator Load (0.2ms) SELECT "instantiation_operators".* FROM "instantiation_operators" WHERE "instantiation_operators"."id" = $1 LIMIT $2 [["id", 3], ["LIMIT", 1]] 
    Activity Load (0.2ms) SELECT "activities".* FROM "activities" WHERE "activities"."id" = $1 LIMIT $2 [["id", 7], ["LIMIT", 1]] 
    CACHE (0.0ms) SELECT "instantiation_operators".* FROM "instantiation_operators" WHERE "instantiation_operators"."id" = $1 LIMIT $2 [["id", 3], ["LIMIT", 1]] 
false 

...

@task.errors 
#<ActiveModel::Errors:0x007fcd984174c8 @base=#<Task id: nil, name: "Forrest Wright", description: "In dolores voluptatibus maiores in fugit fuga Quis...", priority: "Voluptatem modi quod consequatur vel sed est exerc...", category: "Sequi vitae at explicabo In", status: "Omnis quo sed obcaecati voluptate corporis cumque ...", startDate: "1986-07-04", comments: "Ut fugit dicta voluptatem Ullam voluptas id et", TTC: 86, endDate: nil, created_at: nil, updated_at: nil, case_id: 1>, @messages={:"task_activities.task"=>["must exist"]}, @details={"task_activities.task"=>[{:error=>:blank}]}> 

Answer 1

をあなたがproduction.logするモデルエラーをログに記録する必要があります。

byebug（Railsの5+）と

def your_action 
    logger.debug @task.errors 
    [...] 
end 

またはデバッグやデバッガ（Railsの4-）

def your_action 
    [...] 
    byebug 
    [...] 
end 

そして、あなたは@task変数を検査することができ、レール・サーバでのこれを達成するための方法が行うことです。

Answer 2

の前に, inverse_of: :taskを追加することでした。 問題は、タスクアクティビティがタスクの前に保存しようとしていたことでした。私はbyebug（ヘッドアップのために@ vl3に感謝）を使用し、@ save.errorsを検査した。何TASK_IDは、タスク・アクティビティに割り当てられていないされていたことを

@messages={:"task_activities.task"=>["must exist"]}

も：私がメッセージを見つけました。

この行を追加すると、タスクをタスクアクティビティの前に作成するだけです。