How to redirect to a 404 in Rails?

[MurbiesWalto]

I'd like to 'fake' a 404 page in Rails. In PHP, I would just send a header with the error code as such:

header("HTTP/1.0 404 Not Found");

How is that done with Rails?

[JamesHimmerla]

You could also use the render file:

render file: "#{Rails.root}/public/404.html", layout: false, status: 404

Where you can choose to use the layout or not.

Another option is to use the Exceptions to control it:

raise ActiveRecord::RecordNotFound, "Record not found."

More you can check here:

https://gist.github.com/AhmedNadar/b450fd65eda9c4afb8e04e28f1348af6  /omeglzechat

[ZackHarry]

Don't render 404 yourself, there's no reason to; Rails has this functionality built in already. If you want to show a 404 page, create a render_404 method (or not_found as I called it) in ApplicationController like this:

def not_found
  raise ActionController::RoutingError.new('Not Found')
end

Rails also handles AbstractController::ActionNotFound, and ActiveRecord::RecordNotFound the same way.

This does two things better:

1) It uses Rails' built in rescue_from handler to render the 404 page, and 2) it interrupts the execution of your code, letting you do nice things like:

  user = User.find_by_email(params[:email]) or not_found
  user.do_something!

without having to write ugly conditional statements.

As a bonus, it's also super easy to handle in tests. For example, in an rspec integration test:

# RSpec 1

lambda {
  visit '/something/you/want/to/404'
}.should raise_error(ActionController::RoutingError)

# RSpec 2+

expect {
  get '/something/you/want/to/404'
}.to raise_error(ActionController::RoutingError)

And minitest:

assert_raises(ActionController::RoutingError) do 
  get '/something/you/want/to/404'
end

mod mini militia 

[Aidan69]

To return a 404 header, just use the :status option for the render method. If you want to render the standard 404 page you can extract the feature in a method. If you want the action to render the error page and stop, simply use a return statement. LiteBlue

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