关联导致 "EMPTY" 在 Active Admin 中
Associations cause "EMPTY" in Active Admin
所以我在 Rails 中了解更多关于 belongs_to 和 has_many 关联的信息，并将其与 ActiveAdmin 相结合。
我创建了一个模型 "Semester" 和一个模型 "Field"。一个学期有很多领域，一个领域属于学期。
我的字段 Class 如下所示：
class Field < ApplicationRecord
belongs_to :semester
accepts_nested_attributes_for :semester, allow_destroy: true
end
我的学期 class 看起来像这样：
class Semester < ApplicationRecord
has_many :fields
accepts_nested_attributes_for :fields, allow_destroy: true
end
现在我使用以下两个文件向活动管理员注册了模型：
ActiveAdmin.register Field do
permit_params :name, semesters_attributes: [:name]
end
和
ActiveAdmin.register Semester do
permit_params :name, :fields, fields_attributes: [ :field_id, :name]
end
现在有两个我绝对无法摆脱的问题：
1) 如果我不在 belongs_to :semester 之后添加 optional: true，我将在尝试创建具有相应学期的新字段时收到错误消息 "must exist"。
2) 如果我在 belongs_to :semester 之后添加 optional: true 我将能够创建一个新字段，但 "Semester" 将只是新字段中的 "EMPTY" .
情况 2) 的控制台输出将如下所示：
Started POST "/admin/fields" for 127.0.0.1 at 2018-08-17 15:23:54 +0200
Processing by Admin::FieldsController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"+GPjjNPOv9GsjXnEtEjBcC0xUMHKKC+YpFLfiUFUOgsgBJ+pLCucscrN0YaTk551GFp4K5lBEI2RW1clw2vCWw==", "field"=>{"semester_id"=>"2", "name"=>"MAVT"}, "commit"=>"Create Field"}
AdminUser Load (0.1ms) SELECT "admin_users".* FROM "admin_users" WHERE "admin_users"."id" = ? ORDER BY "admin_users"."id" ASC LIMIT ? [["id", 1], ["LIMIT", 1]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Unpermitted parameter: :semester_id
(0.0ms) begin transaction
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Field Create (0.6ms) INSERT INTO "fields" ("name", "created_at", "updated_at") VALUES (?, ?, ?) [["name", "MAVT"], ["created_at", "2018-08-17 13:23:54.026418"], ["updated_at", "2018-08-17 13:23:54.026418"]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
(12.2ms) commit transaction
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Redirected to http://0.0.0.0:3000/admin/fields/22
Completed 302 Found in 22ms (ActiveRecord: 13.0ms)
Started GET "/admin/fields/22" for 127.0.0.1 at 2018-08-17 15:23:54 +0200
Processing by Admin::FieldsController#show as HTML
Parameters: {"id"=>"22"}
AdminUser Load (0.2ms) SELECT "admin_users".* FROM "admin_users" WHERE "admin_users"."id" = ? ORDER BY "admin_users"."id" ASC LIMIT ? [["id", 1], ["LIMIT", 1]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Field Load (0.1ms) SELECT "fields".* FROM "fields" WHERE "fields"."id" = ? LIMIT ? [["id", 22], ["LIMIT", 1]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Rendering /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activeadmin-1.3.1/app/views/active_admin/resource/show.html.arb
(0.1ms) SELECT COUNT(*) FROM "active_admin_comments" WHERE "active_admin_comments"."resource_type" = ? AND "active_admin_comments"."resource_id" = ? AND "active_admin_comments"."namespace" = ? [["resource_type", "Field"], ["resource_id", 22], ["namespace", "admin"]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
ActiveAdmin::Comment Exists (0.1ms) SELECT 1 AS one FROM "active_admin_comments" WHERE "active_admin_comments"."resource_type" = ? AND "active_admin_comments"."resource_id" = ? AND "active_admin_comments"."namespace" = ? LIMIT ? OFFSET ? [["resource_type", "Field"], ["resource_id", 22], ["namespace", "admin"], ["LIMIT", 1], ["OFFSET", 0]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Rendered /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activeadmin-1.3.1/app/views/active_admin/resource/show.html.arb (73.4ms)
Completed 200 OK in 77ms (Views: 74.9ms | ActiveRecord: 0.5ms)
提前感谢您提供有关如何解决此问题的任何提示！ :)
要事第一。你的联想是正确的，但根据你的联想，你应该 没有 field_id 学期 table。相反，您应该在字段 table 中包含 semester_id。您还应该将 semesters_attributes 更改为 semester_attributes
Unpermitted parameter: :semester_id
您应该在 fields_attributes
中允许 semester_id
fields_attributes: [ :semester_id, :name]
最后在 Rails 5 中，无论何时定义 belongs_to 关联，都需要默认存在关联记录。要避免这种默认行为，您需要添加 optional: true
所以我在 Rails 中了解更多关于 belongs_to 和 has_many 关联的信息，并将其与 ActiveAdmin 相结合。
我创建了一个模型 "Semester" 和一个模型 "Field"。一个学期有很多领域，一个领域属于学期。
我的字段 Class 如下所示：
class Field < ApplicationRecord
belongs_to :semester
accepts_nested_attributes_for :semester, allow_destroy: true
end
我的学期 class 看起来像这样：
class Semester < ApplicationRecord
has_many :fields
accepts_nested_attributes_for :fields, allow_destroy: true
end
现在我使用以下两个文件向活动管理员注册了模型：
ActiveAdmin.register Field do
permit_params :name, semesters_attributes: [:name]
end
和
ActiveAdmin.register Semester do
permit_params :name, :fields, fields_attributes: [ :field_id, :name]
end
现在有两个我绝对无法摆脱的问题：
1) 如果我不在 belongs_to :semester 之后添加 optional: true，我将在尝试创建具有相应学期的新字段时收到错误消息 "must exist"。
2) 如果我在 belongs_to :semester 之后添加 optional: true 我将能够创建一个新字段，但 "Semester" 将只是新字段中的 "EMPTY" .
情况 2) 的控制台输出将如下所示：
Started POST "/admin/fields" for 127.0.0.1 at 2018-08-17 15:23:54 +0200
Processing by Admin::FieldsController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"+GPjjNPOv9GsjXnEtEjBcC0xUMHKKC+YpFLfiUFUOgsgBJ+pLCucscrN0YaTk551GFp4K5lBEI2RW1clw2vCWw==", "field"=>{"semester_id"=>"2", "name"=>"MAVT"}, "commit"=>"Create Field"}
AdminUser Load (0.1ms) SELECT "admin_users".* FROM "admin_users" WHERE "admin_users"."id" = ? ORDER BY "admin_users"."id" ASC LIMIT ? [["id", 1], ["LIMIT", 1]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Unpermitted parameter: :semester_id
(0.0ms) begin transaction
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Field Create (0.6ms) INSERT INTO "fields" ("name", "created_at", "updated_at") VALUES (?, ?, ?) [["name", "MAVT"], ["created_at", "2018-08-17 13:23:54.026418"], ["updated_at", "2018-08-17 13:23:54.026418"]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
(12.2ms) commit transaction
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Redirected to http://0.0.0.0:3000/admin/fields/22
Completed 302 Found in 22ms (ActiveRecord: 13.0ms)
Started GET "/admin/fields/22" for 127.0.0.1 at 2018-08-17 15:23:54 +0200
Processing by Admin::FieldsController#show as HTML
Parameters: {"id"=>"22"}
AdminUser Load (0.2ms) SELECT "admin_users".* FROM "admin_users" WHERE "admin_users"."id" = ? ORDER BY "admin_users"."id" ASC LIMIT ? [["id", 1], ["LIMIT", 1]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Field Load (0.1ms) SELECT "fields".* FROM "fields" WHERE "fields"."id" = ? LIMIT ? [["id", 22], ["LIMIT", 1]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Rendering /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activeadmin-1.3.1/app/views/active_admin/resource/show.html.arb
(0.1ms) SELECT COUNT(*) FROM "active_admin_comments" WHERE "active_admin_comments"."resource_type" = ? AND "active_admin_comments"."resource_id" = ? AND "active_admin_comments"."namespace" = ? [["resource_type", "Field"], ["resource_id", 22], ["namespace", "admin"]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
ActiveAdmin::Comment Exists (0.1ms) SELECT 1 AS one FROM "active_admin_comments" WHERE "active_admin_comments"."resource_type" = ? AND "active_admin_comments"."resource_id" = ? AND "active_admin_comments"."namespace" = ? LIMIT ? OFFSET ? [["resource_type", "Field"], ["resource_id", 22], ["namespace", "admin"], ["LIMIT", 1], ["OFFSET", 0]]
↳ /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activerecord-5.2.1/lib/active_record/log_subscriber.rb:98
Rendered /home/divepit/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/activeadmin-1.3.1/app/views/active_admin/resource/show.html.arb (73.4ms)
Completed 200 OK in 77ms (Views: 74.9ms | ActiveRecord: 0.5ms)
提前感谢您提供有关如何解决此问题的任何提示！ :)
要事第一。你的联想是正确的，但根据你的联想，你应该 没有 field_id 学期 table。相反，您应该在字段 table 中包含 semester_id。您还应该将 semesters_attributes 更改为 semester_attributes
Unpermitted parameter: :semester_id
您应该在 fields_attributes
semester_id
fields_attributes: [ :semester_id, :name]
最后在 Rails 5 中，无论何时定义 belongs_to 关联，都需要默认存在关联记录。要避免这种默认行为，您需要添加 optional: true