Rails 5 improves redirect_to :back method

In Rails 4.x, for going back to previous page we use redirect_to :back.

However sometimes we get ActionController::RedirectBackError exception when HTTP_REFERER is not present.

class PostsController < ApplicationController
  def publish
    post = Post.find params[:id]
    post.publish!

    redirect_to :back
  end
end

This works well when HTTP_REFERER is present and it redirects to previous page.

Issue comes up when HTTP_REFERER is not present and which in turn throws exception.

To avoid this exception we can use rescue and redirect to root url.

class PostsController < ApplicationController
  rescue_from ActionController::RedirectBackError, with: :redirect_to_default

  def publish
    post = Post.find params[:id]
    post.publish!
    redirect_to :back
  end

  private

  def redirect_to_default
    redirect_to root_path
  end
end

In Rails 5, redirect_to :back has been deprecated and instead a new method has been added called redirect_back.

To deal with the situation when HTTP_REFERER is not present, it takes required option fallback_location.

class PostsController < ApplicationController

  def publish
    post = Post.find params[:id]
    post.publish!

    redirect_back(fallback_location: root_path)
  end
end

This redirects to HTTP_REFERER when it is present and when HTTP_REFERER is not present then redirects to whatever is passed as fallback_location.