rails 4 before_actions with dynamic parameters - ruby-on-rails

How to set a before_action method with dynamic params, I keep getting an error wrong number of arguments (0 for 1)
class PagesController < ApplicationController
before_action :set_categories
before_action :redirect_if_path_has_changed, only: [:products, :detail]
def home
end
def products
#category = Category.find(params[:id])
#products = #category.products.order("created_at").page(params[:page]).per(6)
redirect_if_path_has_changed(products_by_category_path(#category))
end
def detail
#product = Product.find(params[:id])
redirect_if_path_has_changed(product_details_path(#product))
end
private
def set_categories
#categories = Category.all
end
def redirect_if_path_has_changed(path_requested)
redirect_to path_requested, status: :moved_permanently if request.path != path_requested
end
end
Thank you before

You can do it like this:
before_action only: [:products, :detail] do
redirect_if_path_has_changed("value")
end
Try this. The above works when you need to set any value or something before the action. In you case you want to first find the product or detail from database then you want to redirect to that path. So before_action just calls before the two actions which is not useful in your case.

Related

Rails ERB Validation

I'm trying to add a validation to my Rails app in order to display an error message if the user goes to the wrong id. The project has reviews, if I go to http://localhost:3000/reviews/:id that doesn't exist the app crashes, I'd like to prevent the runtime error by displaying a message.
In the model, I got this validation:
class Review < ApplicationRecord
validates :id, presence: true
end
Then, in the reviews/show.html.erb file, I'm trying this:
<% if #review.valid? %>
<div class='review-header'>
....
</div>
<% else %>
<% #review.errors.objects.first.full_message %>
<% end %>
This is also the Reviews Controller:
class ReviewsController < ApplicationController
before_action :set_review, only: [:show, :edit, :update, :destroy]
before_action :authorize!, only: [:edit, :destroy]
def index
if params[:search]
#reviews = Review.where("title like ?", "%#{params[:search]}%")
else
#reviews = Review.all
end
end
def new
#review = Review.new
#comment = Comment.new
#comment.review_id = #review.id
#We need to declare the comments in the new action.
end
def create
#review = current_user.reviews.new(review_params)
if #review.save
redirect_to review_path(#review)
else
render 'new'
end
end
def show
#comment = Comment.new
#We also need to declare the new comment in the show action.
end
def edit
end
def update
if #review.update(review_params)
redirect_to review_path(#review)
else
render 'edit'
end
end
def destroy
#review.destroy
redirect_to reviews_path
end
private
def set_review
#review = Review.find_by(id: params[:id])
end
def review_params
params.require(:review).permit(:title, :content, :category_id, :search)
end
def authorize!
authorize #review #authorize method using the Pundit gem
end
end
However, my project keep crashing rather than showing a message. If there's any way I can make this work? Thanks.
The whole setup of the question is actually broken.
You don't need to add a model validation for the id since ids are automatically generated by the database when you insert records. On most databases primary keys are also non-nullable. Adding the validation will actually break the model as will prevent you from saving records without manually assigning an id (bad idea).
Its also not the models job to verify that a record can be found in the controller. Instead your controller should use find so that it bails early if the record cannot be found:
class ReviewsController < ApplicationController
before_action :set_review, only: [:show, :edit, :update, :destroy]
before_action :authorize!, only: [:edit, :destroy]
private
def set_review
#review = Review.find(params[:id])
end
end
This halts execution of the method and other callbacks and prevents the NoMethodErrors that are bound to occur. There is no sense in continuing to process a request if the record that its supposed to CRUD doesn't exist.
By default Rails will handle an uncaught ActiveRecord::RecordNotFound exception by rendering a static HTML page located at public/404.html and returning a 404 status code. If you want to customize this on the controller level use rescue_from:
class ReviewsController < ApplicationController
before_action :set_review, only: [:show, :edit, :update, :destroy]
before_action :authorize!, only: [:edit, :destroy]
rescue_from ActiveRecord::RecordNotFound, with: :not_found
private
def set_review
#review = Review.find(params[:id])
end
def not_found
# renders app/reviews/not_found.html.erb
render :not_found,
status: :not_found
end
end
Note that this should be done in different view. If you add a <% if #review.present? %> to your reviews/show.html.erb view you should get your Rails licence revoked as the views one and only job is to display the review.
You can also configure the responses on the application level with config.exceptions_app.
The problem is that if the ID does not correspond to a review in the database, the #review object will be nil, and your line if #review.valid? will throw an error.
You need a different test, something like
<% if #review.present? %>
<div class='review-header'>
....
</div>
<% else %>
Review does not exist.
<% end %>

How To Have A Blog Where Users Can Only Edit Posts For A Limited Time in Ruby on Rails

I've made a very simple blog where users can Create, Edit and Delete posts however I want to add functionality where users can only Edit for a limited time (say 3 days). My understanding of Ruby is not strong enough to know how to do this so any help is appreciated.
This is my Notes (my name for Posts) controller
class NotesController < ApplicationController
before_action :find_note, only: [:show, :edit, :update, :destroy]
def index
#notes = Note.where(user_id: current_user)
end
def show
end
def new
#note = current_user.notes.build
end
def create
#note = current_user.notes.build(note_params)
if #note.save
redirect_to #note
else
render 'new'
end
end
def edit
end
def update
if #note.update(note_params)
redirect_to #note
else
render 'edit'
end
end
def destroy
#note.destroy
redirect_to notes_path
end
private
def find_note
#note = Note.find(params[:id])
end
def note_params
params.require(:note).permit(:title, :content)
end
end
I assume somewhere in the edit method I need to write a rule for restricting the ability to edit posts to only 3 days, using the created_at function somehow? I'm just at a loss as to exactly how to do this.
Any help is appreciated.
Perfect solution for that is :before_filter
class NotesController < ApplicationController
before_filter :check_time!, only: [:edit, :update]
def edit
end
def create
end
private
def check_time!
if Time.now() > #note.created_at + 3.days
flash[:danger] = 'Out of 3 days'
redirect_to note_path(#note)
end
end
end

Devise before_action explanation

I am having trouble understanding this line that gets automatically generated in the controller when I install Devise:
before_action :set_post, only: [:show, :edit, :update, :destroy]
I tried reading the documentation but I am unable to make sense of what it does. For example what does the :set_post symbol do? What is it part of?
Any explanations or resources where I can go for further reading would be appreciated.
Suppose you have a controller like this:
class PostController < ApplicationController
def index
#posts = Post.all
end
def show
#post = Post.find(params[:id])
end
def edit
#post = Post.find(params[:id])
end
end
You see that in show and edit actions there is the same code, you're breaking the DRY principle, so to avoid code repetitions you set an action (method):
def set_post
#post = Post.find(params[:id])
end
that will be performed before the actions that require that same code:
before_action :set_post, only: [:show, :edit, :update, :destroy]
In the end you'll have a controller like this:
class PostController < ApplicationController
def index
#posts = Post.all
end
def show
end
def edit
end
private
def set_post
#post = Post.find(params[:id])
end
end
:set_post - a method at the end of the controller.
The device does not have anything to do with

Update route in rails doesn't respond well to after_action?

class FrogsController < ApplicationController
before_action :find_frog, only: [:edit, :update, :show, :destroy]
after_action :redirect_home, only: [:update, :create, :destroy]
def index
#frogs = Frog.all
end
def new
#ponds = Pond.all
#frog = Frog.new
end
def create
#frog = Frog.create(frog_params)
end
def edit
#ponds = Pond.all
end
def update
#frog.update_attributes(frog_params)
end
def show
end
def destroy
#frog.destroy
end
private
def find_frog
#frog = Frog.find(params[:id])
end
def frog_params
params.require(:frog).permit(:name, :color, :pond_id)
end
def redirect_home
redirect_to frogs_path
end
end
Hi all. I was wondering if someone could explain to me why the update route in rails can't take my after_action of redirecting (custom made method on the bottom) it home. The error that I get when i include update in the after_action is "Missing template frogs/update".
This is going to cause me to manually add a redirect_to frogs_path inside the update method.
thanks!
The after_action callback is triggered after the action has run its course. You cannot use it to render or redirect. Do that within the action itself by calling the method:
def update
...
redirect_home
end

refactoring generated action code in the controller

If I generate a scaffold I get the standard actions index, new, show, create .... all of which contain a line e.g. like
#comment = Comment.find(params[:id])
Does it make sense to put this line in a seperate method into the controller like
def load
#comment = Comment.find(params[:id])
end
Is this an advantage? Thx for your time
Yes to the separate method, and also yes to using a before_filter.
class CommentsController < ApplicationController
# Whitelist your before_filter like this. Or you can blacklist it with :except => []
before_filter :load_comment, :only => [:edit, :update, :destroy, :show]
def show
end
def index
#comments = Comment.all
end
def new
#comment = Comment.new
end
# etc ...
protected
def load_comment
#comment = Comment.find(params[:id])
end
end

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