Rails 4 _form部分创建新记录，但不会编辑当前记录

Question

我已经构建了一个具有业务的简单应用程序，并且这些业务有很多评论。我正在使用部分_form来创建/更新评论。创建操作可以正常工作，但更新操作会创建一个新的审阅，而不是像审查时那样更新审阅。下面是相关的代码（不相关的代码简洁，删除）：

从routes.rb代码：

resources :businesses do 
    resources :reviews 
end 

从models/business.rb代码：

class Business < ActiveRecord::Base 
    has_many :reviews, dependent: :destroy 
    validates_associated :reviews 
end 

从models/review.rb代码：

class Review < ActiveRecord::Base 
    belongs_to :business 
    belongs_to :user 
end 

代码从controllers/reviews_controller.rb：

class ReviewsController < ApplicationController 
    load_and_authorize_resource 

    before_filter :load_business 

    def new 
    end 

    def index 
    end 

    def create 
    @review = @business.reviews.create(review_params) 
    @review.user_id = current_user.id 
    @review.reviewer = current_user.first_name + ' ' + current_user.last_name 
    if @review.save 
     redirect_to business_path(@business) 
     flash[:notice] = 'Review posted!' 
    else 
     redirect_to business_path(@business) 
     flash[:danger] = 'Your review has an error. Please double check!' 
    end 
    end 

    def edit 
    @review = @business.reviews.find(params[:id]) 
    end 

    def update 
    @review = @business.reviews.find(params[:id]) 
    if @review.update(params[review_params]) 
     redirect_to businesses_path(@business) 
     flash[:notice] = 'Review updated!' 
    else 
     render :action => 'edit' 
    end 
    end 

    def destroy 
    @review = @business.reviews.find(params[:id]) 
    @review.destroy 
    redirect_to business_path(@business) 
    flash[:notice] = "Review deleted." 
    end 

    private 

    def load_business 
    @business = Business.find(params[:business_id]) 
    end 

    def review_params 
    params.require(:review).permit(:review, :rating) 
    end 
end 

代码`评论/ _form.html.erb：

<%= simple_form_for([@business, @business.reviews.build]) do |f| %> 
    <%= f.error_notification %> 
    <p> 
    <%= f.input :review %> 
    </p> 
    <p> 
    <%= f.input :rating, collection: 1..10 %> 
    </p> 
    <p> 
    <%= f.submit :class => 'btn btn-primary' %> 
    </p> 
<% end %> 

的评语是在商业＃放映视图作为部分呈现。代码`评论/ _review.html.erb：

<% if !review.user_id.nil? %> 
    <div class="well"> 
    <p> 
     <strong>Reviewer:</strong> 
     <%= review.reviewer %> 
    </p> 
    <p> 
     <strong>Review:</strong> 
     <%= review.review %> 
    </p> 
    <p> 
     <strong>Rating:</strong> 
     <%= review.rating %> 
    </p> 
    <span class = "timestamp"> 
     posted <%= time_ago_in_words(review.created_at) %> ago. 
    </span> 
    <% if can? :update, review %> 
     <span class = "timestamp"> 
     <%= link_to "Edit", [:edit, review.business, review], class: 'btn btn-small' %>| 
     <%= link_to "Delete", [review.business, review], method: :delete, 
        data: { confirm: 'Are you sure?' } %> 
     </span> 
    <% end %> 
    </div> 
<% end %> 

代码reviews/edit.html.erb：

<h1>Edit Review</h1> 

<%= render 'form', review: @review %> 

<button type="button" class="btn btn-default"><%= link_to 'Back', businesses_path %></button> 

奇怪的是，当我点击_review.html.erb “编辑” 链接，这是生成的URL似乎是正确的，例如我得到http://localhost:3000/businesses/10/reviews/82/edit。然而，_form.html.erb是空的，我期望它会被当前的数据填充＃82。此外，当我点击“创建评论”按钮时，它会创建一个新的评论，并且不会编辑评论＃82。

这里后，我的服务器日志点击现有的评论“编辑”：

Started GET "/businesses/3/reviews/81/edit" for 127.0.0.1 at 2014-08-28 19:18:58 -0500 
Processing by ReviewsController#edit as HTML 
    Parameters: {"business_id"=>"3", "id"=>"81"} 
    User Load (0.8ms) SELECT "users".* FROM "users" WHERE "users"."id" = 8 ORDER BY "users"."id" ASC LIMIT 1 
    Review Load (6.9ms) SELECT "reviews".* FROM "reviews" WHERE "reviews"."id" = $1 LIMIT 1 [["id", 81]] 
    Business Load (0.5ms) SELECT "businesses".* FROM "businesses" WHERE "businesses"."id" = $1 LIMIT 1 [["id", 3]] 
    Review Load (27.4ms) SELECT "reviews".* FROM "reviews" WHERE "reviews"."business_id" = $1 AND "reviews"."id" = $2 LIMIT 1 [["business_id", 3], ["id", 81]] 
    Rendered reviews/_form.html.erb (107.0ms) 
    Rendered reviews/edit.html.erb within layouts/application (143.4ms) 
Completed 200 OK in 967ms (Views: 669.2ms | ActiveRecord: 35.6ms) 


Started POST "/businesses/3/reviews" for 127.0.0.1 at 2014-08-28 19:19:23 -0500 
Processing by ReviewsController#create as HTML 
    Parameters: {"utf8"=>"✓", "authenticity_token"=>"<redacted>", "review"=>{"review"=>"Edit review #81.", "rating"=>"1"}, "commit"=>"Create Review", "business_id"=>"3"} 
    User Load (0.8ms) SELECT "users".* FROM "users" WHERE "users"."id" = 8 ORDER BY "users"."id" ASC LIMIT 1 
    Business Load (0.6ms) SELECT "businesses".* FROM "businesses" WHERE "businesses"."id" = $1 LIMIT 1 [["id", 3]] 
    (28.9ms) BEGIN 
    SQL (132.9ms) INSERT INTO "reviews" ("business_id", "created_at", "rating", "review", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id" [["business_id", 3], ["created_at", "2014-08-29 00:19:23.470750"], ["rating", 1], ["review", "Edit review #81."], ["updated_at", "2014-08-29 00:19:23.470750"]] 
    (39.7ms) COMMIT 
    (0.3ms) BEGIN 
    SQL (0.9ms) UPDATE "reviews" SET "reviewer" = $1, "updated_at" = $2, "user_id" = $3 WHERE "reviews"."id" = 83 [["reviewer", "<redacted>"], ["updated_at", "2014-08-29 00:19:23.692880"], ["user_id", 8]] 
    (17.5ms) COMMIT 
Redirected to http://localhost:3000/businesses/3 
Completed 302 Found in 553ms (ActiveRecord: 221.6ms) 


Started GET "/businesses/3" for 127.0.0.1 at 2014-08-28 19:19:23 -0500 
Processing by BusinessesController#show as HTML 
    Parameters: {"id"=>"3"} 
    User Load (0.7ms) SELECT "users".* FROM "users" WHERE "users"."id" = 8 ORDER BY "users"."id" ASC LIMIT 1 
    Business Load (0.5ms) SELECT "businesses".* FROM "businesses" WHERE "businesses"."id" = $1 LIMIT 1 [["id", 3]] 
    (0.5ms) SELECT AVG("reviews"."rating") AS avg_id FROM "reviews" WHERE "reviews"."business_id" = $1 [["business_id", 3]] 
    Rendered reviews/_form.html.erb (5.7ms) 
    Review Load (0.6ms) SELECT "reviews".* FROM "reviews" WHERE "reviews"."business_id" = $1 ORDER BY "reviews"."id" DESC [["business_id", 3]] 
    Rendered reviews/_review.html.erb (58.1ms) 
    Rendered businesses/show.html.erb within layouts/application (173.5ms) 
    Rendered users/_avatar.html.haml (13.1ms) 
    Rendered layouts/_navigation.html.haml (30.9ms) 
    Rendered layouts/_messages.html.haml (1.5ms) 
    Rendered layouts/_footer.html.haml (16.5ms) 
    Rendered layouts/_analytics.html.haml (0.6ms) 
    Rendered layouts/_javascripts.html.haml (0.5ms) 
Completed 200 OK in 421ms (Views: 391.5ms | ActiveRecord: 2.3ms) 

很明显的是，在服务器日志中的第二个动作为“已启动POST ......”，这是不正确的。而我在这，我不妨从rake routes提供相关路线：

business_reviews  GET  /businesses/:business_id/reviews(.:format)   reviews#index 
        POST  /businesses/:business_id/reviews(.:format)   reviews#create 
new_business_review GET  /businesses/:business_id/reviews/new(.:format)  reviews#new 
edit_business_review GET  /businesses/:business_id/reviews/:id/edit(.:format) reviews#edit 
business_review  GET  /businesses/:business_id/reviews/:id(.:format)  reviews#show 
        PATCH /businesses/:business_id/reviews/:id(.:format)  reviews#update 
        PUT  /businesses/:business_id/reviews/:id(.:format)  reviews#update 
        DELETE /businesses/:business_id/reviews/:id(.:format)  reviews#destroy 

我已经尝试实现每一个答案，我能找到这里，但无济于事。我发现的最接近我的确切问题是这一个，但它也没有帮助：Rails: Use same partial for creating and editing nested items

非常感谢。

Answer 1

根据你在控制台中的输出，你在更新stmt之前有一个sql插入stmt。您的代码在表单中导致它。即使在编辑时，@business.reviews.build也会创建新的审阅对象。

更新您的form_for到：

<%= simple_form_for([@business, @review]) do |f| %> 

而不是@business.reviews.build。您应该在控制器而不是视图中创建对象。

因此，您可能还需要在新操作中重新检查对象。

def new 
    @review = @business.reviews.build 
    end 

---

我为你简化代码，可以使事情变得更容易一些建议。

使用评论ID来查找评论，而不是通过业务。
如编辑和修改代码，你可以：

def edit 
    @review = Reviews.find(params[:id]) 
    end 

    def update 
    @review = Reviews.find(params[:id]) 
    ... 
    end