问题
I am trying to set up a feature on my Ruby on Rails app that lets users to review pictures.
I've followed this guide as a reference.
http://ruby.about.com/od/rubyonrails/ss/blogpart4_4.htm
From my experiences working on other Ruby on Rails projects, I think a Posts/Comments relationship model can be used here for a Pictures/Reviews relationship.
I first generated a scaffold.
rails g scaffold review name:string body:text picture:references
I would like each picture page to have a separate page for its own reviews.
Since I don't need an Index Page for my reviews controller, I removed this line from my routes.rb file
resources: reviews
I replaced that by creating routes
match '/pictures/:id/reviews', to: 'reviews#show', via: 'get'
match '/pictures/:id/reviews/edit', to: 'reviews#edit', via: 'get'
match '/pictures/:id/reviews/new', to: 'reviews#new', via: 'get'
Here, my path involves nesting reviews inside pictures.
Route
favorite_picture_path PUT /pictures/:id/favorite(.:format) pictures#favorite
pictures_path GET /pictures(.:format) pictures#index
POST /pictures(.:format) pictures#create
new_picture_path GET /pictures/new(.:format) pictures#new
edit_picture_path GET /pictures/:id/edit(.:format) pictures#edit
picture_path GET /pictures/:id(.:format) pictures#show
PATCH /pictures/:id(.:format) pictures#update
PUT /pictures/:id(.:format) pictures#update
DELETE /pictures/:id(.:format) pictures#destroy
users_path GET /users(.:format) users#index
POST /users(.:format) users#create
new_user_path GET /users/new(.:format) users#new
edit_user_path GET /users/:id/edit(.:format) users#edit
user_path GET /users/:id(.:format) users#show
PATCH /users/:id(.:format) users#update
PUT /users/:id(.:format) users#update
DELETE /users/:id(.:format) users#destroy
sessions_path POST /sessions(.:format) sessions#create
new_session_path GET /sessions/new(.:format) sessions#new
session_path DELETE /sessions/:id(.:format) sessions#destroy
contacts_path POST /contacts(.:format) contacts#create
new_contact_path GET /contacts/new(.:format) contacts#new
root_path GET / pictures#welcome
users_new_path GET /users/new(.:format) users#new
about_path GET /about(.:format) pictures#about
GET /contacts(.:format) contacts#new
GET /users/:id/favorites(.:format) users#favorites
signup_path GET /signup(.:format) users#new
signin_path GET /signin(.:format) sessions#new
signout_path DELETE /signout(.:format) sessions#destroy
GET /pictures/:id/reviews(.:format) reviews#show
GET /pictures/:id/reviews/edit(.:format) reviews#edit
GET /pictures/:id/reviews/new(.:format) reviews#new
updated_path GET /updated(.:format) pictures#newest_updates
GET /top-rated(.:format) pictures#high_ratings
ReviewsController
class ReviewsController < ApplicationController
before_action :set_review, only: [:show, :edit, :update, :destroy]
def show
@picture = Picture.find(params[:id])
@review = Review.find(params[:id])
end
def new
@review = Review.new
end
def edit
@picture = Picture.find(params[:picture_id])
@review = Review.find(params[:id])
end
def create
@picture = Picture.find(params[:picture_id])
@review = @picture.reviews.build(params[:review])
if @review.save
;flash[:notice] = 'Review was successfully created.'
redirect_to @picture
else
flash[:notice] = "Error creating review: #{@review.errors}"
redirect_to @picture
end
end
def update
@picture = Picture.find(params[:picture_id])
@review = Review.find(params[:id])
if @review.update_attributes(params[:review])
flash[:notice] = "Review updated"
redirect_to @picture
else
flash[:error] = "There was an error updating your review"
redirect_to @picture
end
end
def destroy
@picture = Picture.find(params[:picture_id])
@review = Review.find(params[:id])
@review.destroy
redirect_to(@review.post)
end
private
def set_review
@review = Review.find(params[:id])
end
def review_params
params.require(:review).permit(:username, :body, :picture_id)
end
end
I deleted the index action from my ReviewsController.
Models
class Review < ActiveRecord::Base
belongs_to :picture
end
class Picture < ActiveRecord::Base
has_many :reviews
end
Above, I established a one-to-many relationship between pictures and reviews.
Reviews Migration
class CreateReviews < ActiveRecord::Migration
def change
create_table :reviews do |t|
t.string :username
t.text :body
t.references :picture, index: true
t.timestamps
end
end
end
Based on my understanding on Rails, this should work.
Pictures#Show Page
<% @title = "#{@picture.title}" %>
<h4 class = 'indent'>Picture Statistics</h4>
<ul id = 'view'>
<li><strong>Title:</strong> <%= @picture.title %></li>
<li><strong>Category:</strong> <%= @picture.category %></li>
<li><strong>Rating:</strong> <%= pluralize(@picture.rating, 'Star') %></li>
<li><strong>Favorited:</strong> By <%= pluralize(@picture.users.count, 'User') %></li></br>
</ul>
<% if @picture.rating > 4 %>
<button class = 'top-picture'>Top Rated</button>
<% end %>
<%= form_for @picture do |f| %>
<p>
<%= f.label :stars, 'Rating', class: 'indent' %>
<div class= "rating">
1 ☆<%= f.radio_button :stars, '1' %>
2 ☆<%= f.radio_button :stars, '2' %>
3 ☆<%= f.radio_button :stars, '3' %>
4 ☆<%= f.radio_button :stars, '4' %>
5 ☆<%= f.radio_button :stars, '5' %>
</div>
</p>
<p class = 'indent'>
<input class="btn btn-info" type="submit" value="Review">
</p>
<a href = "/pictures/:id/reviews">Reviews</a>
<% end %>
<p class = 'indent'>
<a class="btn btn-info" href="/pictures" role="button">Index</a>
</p>
However, when I click on a link in my Pictures/:id(show page)
<a href = "/pictures/:id/reviews">Reviews</a>
RecordNotFound Error
Active Record::RecordNotFound in ReviewsController#show
Couldn't find Review with id=:id
Extracted source (around line #54):
53 def set_review
54 @review = Review.find(params[:id])
55 end
56
57 def review_params
Since I encountered a RecordNotFound error, I suspect the problem lies in the ReviewsController, most likely with the params.
I believe that I have the right idea, but I made a mistake somewhere. Feedback and criticism are greatly appreciated. Sorry if this sounds like a stupid question, I'm just not very good in Ruby.
回答1:
Routes
For the sake of posterity, you'll be best setting your routes up as follows:
#config/routes.rb
resources :pictures do
resources :reviews, only: [:show, :edit, :new]
end
Whenever you create routes in Rails, you need to remember the entire framework has been built around "objects" / "resources". That's why the routes are known as resourceful routes (and why they have the resources directive) - they allow you to define the routes around the different resources of your application
I've recommend using a nested resources structure.
--
Helpers
Your problem was resolved using the code provided by Santosh and the like. IE:
<%= link_to "Your Link", your_link_path(@object) %>
You need to appreciate how this works. Each time you use a route helper in Rails (in the link_to helper), it will look through your routes & find the details it needs.
You were referencing the following path: pictures/:id/reviews - as discovered, this is wrong because Rails does not have any bearing on the URL of a link besides building it at render time.
Considering Rails is a stateless HTTP-based framework, Rails has to collate any data upon each request. This means if you want to build links, you have to let Rails build the link at render, passing a static set of data through to your controller in the back-end
Hopefully this helps?
回答2:
match '/pictures/:id/reviews', to: 'reviews#show', via: 'get'
match '/pictures/:id/reviews/edit', to: 'reviews#edit', via: 'get'
These 2 routes do not have a review id, but your controller action expects them. make this change
match '/pictures/:picture_id/reviews/:id', to: 'reviews#show', via: 'get'
match '/pictures/:picture_id/reviews/:id/edit', to: 'reviews#edit', via: 'get'
And change this
<a href = "/pictures/:id/reviews">Reviews</a>
to
<a href = "/pictures/#{@picture.id}/reviews/#{@review.id}">Reviews</a>
But you should seriously consider using Resourceful routes and helpers
回答3:
As you have .html.erb file, try to avoid writing raw HTML.
Just update this link:
<a href = "/pictures/:id/reviews">Reviews</a>
To
<%= link_to "Reviews", picture_reviews_path(@picture) %>
Edit:
You should assign names to your match statements like:
match '/pictures/:id/reviews', to: 'reviews#show', via: 'get', :as => 'picture_reviews'
It will generate:
picture_reviews GET /pictures/:id/reviews(.:format) reviews#show
回答4:
Consider using nested resources rather than building them out manually
resources :pictures, except: [:index] do
resources :reviews
end
And as others mentioned, you should use the rails link_to to generate proper URLs
来源：https://stackoverflow.com/questions/25107038/ruby-on-rails-settting-up-reviews-functionality