我正在尝试重新创建类似应用程序的堆栈溢出。一个用户问一个问题，其他人可以回答。我在问题页面上缩进了一个嵌套表单，以从其他用户那里获得答案。
发布答案后，我很难找回数据，并且我在更新操作中的问题控制器页面上未正确设置@answer，并且我不知道如何正确地获取数据假设通过questions_controller传递的参数没有单独设置答案的详细信息，则此变量为空。如何检索与@answer相关的params部分，以便可以设置变量，或者可能需要为此使用不同的路由？
我的表单如下：
<%= form_for @question do |form| %>
<%=form.fields_for :answer do |answer_form| %>
<div class="form-group">
<%=answer_form.text_area :answer_attributes, placeholder: "Add your answer", rows:10, class:"form-control" %>
<%=answer_form.hidden_field :user_id, value: current_user.id, class:'d-none' %>
<%=answer_form.hidden_field :question_id, value: @question.id %>
</div>
<% end %>
<div>
<%=form.submit 'Post Your Answer', class: 'btn-primary' %>
</div>
<% end %>
我的问题模型如下：
class Question < ApplicationRecord
has_many :answers, dependent: :destroy
belongs_to :user
accepts_nested_attributes_for :answers
validates :headline, presence: true , length: { minimum: 20 }
validates :body, presence: true, length: { minimum: 50 }
validates_associated :answers
end
，答案模型为：
class Answer < ApplicationRecord
belongs_to :user
belongs_to :question
validates :body, presence: true, length: { minimum: 50 }
end
问题控制器：
class QuestionsController < ApplicationController
before_action :authenticate_user!, except: [:index, :show]
before_action :set_question, except: [:index, :new, :create]
def index
@questions = Question.all.order("id DESC")
end
def show
@question = Question.find(params[:id])
@user = User.find(@question.user_id)
@answers = @question.answers
@answer = Answer.new
end
def new
@question = Question.new
@question.answers.new
end
def create
@question = current_user.questions.new(question_params)
if @question.save
flash[:notice] = "You have successfully posted your question"
redirect_to @question
else
@errors = @question.errors.full_messages
render action: :new
end
end
def edit
set_question
@question = Question.find(params[:id])
end
def update
@question = Question.find(params[:id])
@question.update(question_params)
@answer = @question.answers.new(question_params)
@question.answers.first.user_id = current_user.id
if @question.save
flash[:notice] = "You have sucessfully posted your answer"
redirect_to @question
else
redirect_to new_question_answer_path(@answer), flash: { danger: @question.errors.full_messages.join(",")}
end
end
private
def set_question
@question = Question.find(params[:id])
end
def question_params
params.require(:question).permit(:headline, :body, :user_id, :answer, answers_attributes:[:body, :user_id, :question_id])
end
end
答案控制器：
class AnswersController < ApplicationController
before_action :find_question
def index
@answers = @question.answers
@user = User.find(@question.user_id)
end
def show
@answer = Answer.find(params[:id])
@user = User.find(@question.user_id)
end
def new
@answer = Answer.new(:question_id => @question.id)
end
def create
@answer = Answer.new(answer_params)
if @answer.save
flash[:notice] = "You have sucessfully created the answer."
redirect_to(answers_path(@answer, :question_id => @question.id))
else
flash[:alert] = "Failed to save the answer."
@errors = @answer.errors.full_messages
render :new
end
end
def edit
@answer = Answer.find(params[:id])
end
def update
@answer = Answer.find(params[:id])
if @answer.update_attributes(answer_params)
flash[:notice] = "You have sucessfully updated the answer."
redirect_to(answer_path(@answer, :question_id => @question.id))
else
render :edit
end
end
def delete
@answer = Asnwer.find(params[:id])
end
def destroy
@answer = Answer.find(params[:id])
@answer.destroy
flash[:notice] = "Answer was destroyed"
redirect_to(answers_path)
end
private
def answer_params
params.require(:answer).permit(:body, :user_id, :question_id)
end
def find_question
@question = Question.find(params[:question_id])
end
end
我的路线文件如下：
Rails.application.routes.draw do
get 'questions/index'
root to: 'questions#index'
resources :questions do
resources :answers
end
devise_for :users
# For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
end
更新：这是从服务器启动到显示索引页面到我进入问题页面并记录答案的那一刻的日志
rails server
=> Booting Puma
=> Rails 5.2.2 application starting in development
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.12.0 (ruby 2.6.0-p0), codename: Llamas in Pajamas
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop
Started GET "/questions/11/answers" for 127.0.0.1 at 2019-03-07 16:10:13 +0600
(1.4ms) SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC
↳ /Users/irina/.rvm/gems/ruby-2.6.0/gems/activerecord-5.2.2/lib/active_record/log_subscriber.rb:98
Processing by AnswersController#index as HTML
Parameters: {"question_id"=>"11"}
Question Load (0.8ms) SELECT "questions".* FROM "questions" WHERE "questions"."id" = $1 LIMIT $2 [["id", 11], ["LIMIT", 1]]
↳ app/controllers/answers_controller.rb:65
User Load (2.2ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2 [["id", 3], ["LIMIT", 1]]
↳ app/controllers/answers_controller.rb:6
Rendering answers/index.html.erb within layouts/application
Answer Load (0.9ms) SELECT "answers".* FROM "answers" WHERE "answers"."question_id" = $1 [["question_id", 11]]
↳ app/views/answers/index.html.erb:11
User Load (1.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" ASC LIMIT $2 [["id", 3], ["LIMIT", 1]]
↳ app/views/answers/_new.html.erb:7
Rendered answers/_new.html.erb (61.7ms)
Rendered answers/index.html.erb within layouts/application (92.7ms)
[Webpacker] Compiling…
Started GET "/questions/11/answers" for 127.0.0.1 at 2019-03-07 16:10:18 +0600
Processing by AnswersController#index as HTML
Parameters: {"question_id"=>"11"}
Question Load (1.4ms) SELECT "questions".* FROM "questions" WHERE "questions"."id" = $1 LIMIT $2 [["id", 11], ["LIMIT", 1]]
↳ app/controllers/answers_controller.rb:65
User Load (1.4ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2 [["id", 3], ["LIMIT", 1]]
↳ app/controllers/answers_controller.rb:6
Rendering answers/index.html.erb within layouts/application
Answer Load (1.3ms) SELECT "answers".* FROM "answers" WHERE "answers"."question_id" = $1 [["question_id", 11]]
↳ app/views/answers/index.html.erb:11
User Load (1.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" ASC LIMIT $2 [["id", 3], ["LIMIT", 1]]
↳ app/views/answers/_new.html.erb:7
Rendered answers/_new.html.erb (9.3ms)
Rendered answers/index.html.erb within layouts/application (18.5ms)
Completed 200 OK in 133ms (Views: 108.3ms | ActiveRecord: 18.4ms)
[Webpacker] Compilation failed:
Hash: 53a953077891e4cef2e8
Version: webpack 3.12.0
Time: 2928ms
Asset Size Chunks Chunk Names
application-c57a289721a93641de38.js 3.1 kB 0 [emitted] application
application-c57a289721a93641de38.js.map 2.49 kB 0 [emitted] application
manifest.json 142 bytes [emitted]
[0] ./app/javascript/packs/application.js 346 bytes {0} [built] [failed] [1 error]
ERROR in ./app/javascript/packs/application.js
Module build failed: SyntaxError: Unexpected token (14:15)
12 | if(window.railsEnv && window.railsEnv === 'development'){
13 | try {
> 14 | render(<App />, reactElement)
| ^
15 | } catch (e) {
16 | render(<RedBox error={e} />, reactElement)
17 | }
Completed 200 OK in 11715ms (Views: 11626.9ms | ActiveRecord: 27.7ms)
Started PATCH "/questions/11" for 127.0.0.1 at 2019-03-07 16:10:41 +0600
Processing by QuestionsController#update as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"q7HQt4uGPwBIIz0icswfJLWMRk6MiopIfWu9JBcjkuX1VpGBdwlwZu903NDuebSaX8Y90VHnvcEoaV8unV2zkw==", "question"=>{"answer"=>{"answer_attributes"=>"This is the test answer to see how the information goes through", "user_id"=>"3", "question_id"=>"11"}}, "commit"=>"Post Your Answer", "id"=>"11"}
User Load (0.8ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" ASC LIMIT $2 [["id", 3], ["LIMIT", 1]]
↳ /Users/irina/.rvm/gems/ruby-2.6.0/gems/activerecord-5.2.2/lib/active_record/log_subscriber.rb:98
Question Load (0.5ms) SELECT "questions".* FROM "questions" WHERE "questions"."id" = $1 LIMIT $2 [["id", 11], ["LIMIT", 1]]
↳ app/controllers/questions_controller.rb:55
CACHE Question Load (0.0ms) SELECT "questions".* FROM "questions" WHERE "questions"."id" = $1 LIMIT $2 [["id", 11], ["LIMIT", 1]]
↳ app/controllers/questions_controller.rb:39
Unpermitted parameter: :answer
(0.5ms) BEGIN
↳ app/controllers/questions_controller.rb:40
User Load (0.7ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2 [["id", 3], ["LIMIT", 1]]
↳ app/controllers/questions_controller.rb:40
Answer Load (0.5ms) SELECT "answers".* FROM "answers" WHERE "answers"."question_id" = $1 [["question_id", 11]]
↳ app/controllers/questions_controller.rb:40
(0.3ms) COMMIT
↳ app/controllers/questions_controller.rb:40
Unpermitted parameter: :answer
(0.3ms) BEGIN
↳ app/controllers/questions_controller.rb:44
CACHE User Load (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2 [["id", 3], ["LIMIT", 1]]
↳ app/controllers/questions_controller.rb:44
(0.4ms) ROLLBACK
↳ app/controllers/questions_controller.rb:44
Completed 500 Internal Server Error in 97ms (ActiveRecord: 8.3ms)
ActionController::UrlGenerationError (No route matches {:action=>"new", :controller=>"answers", :question_id=>nil}, missing required keys: [:question_id]):
app/controllers/questions_controller.rb:48:in `update'
更新NO2。由于此错误设置了@answer，因此@question无法按预期方式保存，并且条件踢的第二部分重定向到new_question_answer_path。我尝试将其更新为edit_question_answer_path，并且给出了相同的错误，没有路由匹配。
如果我在Pry中打开答案，则会得到以下对象：
[1] pry(#<QuestionsController>)> @answer
=> #<Answer:0x00007fc3ec823c98
id: nil,
body: nil,
question_id: 11,
user_id: 3,
selected: nil,
created_at: nil,
updated_at: nil>
更新3 好像将我的route.rb更改为
Rails.application.routes.draw do
resources :questions, :has_many => :answers
root to: 'questions#index'
resources :questions do
resources :answers
end
devise_for :users
end
，并更改答案的形式
<h2> Your Answer </h2>
<%= form_for [@question, Answer.new] do |form| %>
<div class="form-group">
<%=form.text_area :body, placeholder: "Add your answer", rows:10, class:"form-control" %><br>
<%=form.hidden_field :user_id, value: current_user.id, class:'d-none' %>
<%=form.hidden_field :question_id, value: @question.id %>
</div>
<div>
<%=form.submit 'Post Your Answer', class: 'btn-primary' %>
</div>
<% end %>
解决了问题，并帮助解决了问题。我不确定这是否是完美的解决方法）
答案 0 :(得分：0)
就像将我的route.rb更改为
Rails.application.routes.draw do
resources :questions, :has_many => :answers
root to: 'questions#index'
resources :questions do
resources :answers
end
devise_for :users
end
并更改答案的形式
<%= form_for [@question, Answer.new] do |form| %>
<div class="form-group">
<%=form.text_area :body, placeholder: "Add your answer", rows:10,
class:"form-control" %><br>
<%=form.hidden_field :user_id, value: current_user.id, class:'d-none' %>
<%=form.hidden_field :question_id, value: @question.id %>
</div>
<div>
<%=form.submit 'Post Your Answer', class: 'btn-primary' %>
</div>
<% end %>
解决了问题，并帮助解决了问题。我不确定这是否是完美的解决方法）