Double Render Error Rails

Double render error rails

Give this a try:

class UsersController < ApplicationController
  before_filter :signed_in_user

  def create
    return back_button if params[:back_button]

    @profile = current_user.build_profile(params[:user])

    if @profile.nil? || current_user.nil? || @profile.user.nil?
      sign_out
      return redirect_to signup_path
    end

    if @profile.new_record?
      render 'new'
    else
      redirect_to more_questions_path
    end
  end

  private

  def signed_in_user
    unless signed_in?
      store_location
      return redirect_to signin_url, notice: "Please sign in."
    end
  end
end

The reasoning behind it: x and return means x and return nil, thus returns nil. Actually, you try to short-circuit the controller action, and return redirect_to ....

Render multilpe times - Double render in rails

Call performed? to check if render or redirect has already happened.

You might want to change your to code to something like this:

def check_count
  assign_values_from_params

  return if performed?

  if count >= failed_count
    render(partial: params[:view_name], layout: false)
  else
    render(text: 'works')
  end
end

def assign_values_from_params
  # code

  if @date.blank?
    redirect_to(main_index_path) and return
  end

  # code
end

the AbstractController::DoubleRenderError cannot be fixed with redirect_to and return

The problem is in the show action, log_in_first redirects then the show action does whatever it wants, which is redirect or render. This is causing the error.

A better solution is to use before_action for your authentication and authorization and just let the user controller actions do their thing. Something like the below.

  class ApplicationController < ActionController::Base

    def current_user
      User.find_by :id=>session[:user_id]
    end

    def log_in?
      !!session[:user_id]
    end

    def authenticate_user!
      if !log_in?
        session[:error]="You have to log in first to continue your operation"
        redirect_to("/login")
      end
    end

     def authorize_user!
       unless current_user&.id.to_s==params[:id]
         session[:error]="You have no right to do this operation."
         redirect_to "/"
       end
     end
  end

class UsersController < ApplicationController
  before_action :authenticate_user!, only: [:show]
  before_action :authorize_user!, only: [:show]

    def new
        @user = User.new
    end

    def create
        @user = User.new(user_params)
        if @user.save
          session[:user_id]=@user.id
          redirect_to user_path(@user)
        else
          render 'new'
        end
    end

    def show
      @user = User.find_by id: params[:id]
      render 'show'
    end

    private
      def user_params
        params.require(:user).permit(:name,:password,:email,:email_confirmation)
      end
end

How can I avoid double render in this situation?

You don't really need to have the rescue_from StandardError as this is the default behaviour of Rails. Rails has a middleware called PublicExceptions which does (mostly) what you want so you can just let the StandardError propagate.

Instead of { error: "Internal Server Error" } it will render this

{ 
  status: status, 
  error: Rack::Utils::HTTP_STATUS_CODES.fetch(status, Rack::Utils::HTTP_STATUS_CODES[500]) 
}

which in case of an exception will render { status: 500, error: "Internal Server Error" }. This should be a reasonable compromise.

For development you could think about adapting this middleware. You can set it with config.exceptions_app.

https://guides.rubyonrails.org/configuring.html#rails-general-configuration

https://api.rubyonrails.org/classes/ActionDispatch/PublicExceptions.html

https://github.com/rails/rails/blob/master/actionpack/lib/action_dispatch/middleware/public_exceptions.rb#L14

Why am I getting AbstractController::DoubleRenderError when calling redirect_to in after_action?

By default, Rails will render views that correspond to the controller action. See Rails Guides.

So in your create and destroy actions, Rails is performing a render by default. Then your after_action (which happens after the action) is redirecting, so it's double rendering.

Instead of an after_action, you could call the goto_articles_page method in your controller actions.

For example:

  def destroy
    @comment.destroy
    goto_articles_page
  end

  def goto_articles_page
    redirect_to article_path(@article) #return not needed
  end

DoubleRenderError but only one render

render and head are both methods that perform a render; you only want to call one of them.

# This is all you need
head :ok

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