---
title: "Configure local_request"
description:
  "How does Rails handle exceptions?  Rails exception handling depends on two
  factors and we are going to discuss both of them here."
canonical_url: "https://www.bigbinary.com/blog/rescue_action_in_public-local_request-and-how-to-configure-local_request"
markdown_url: "https://www.bigbinary.com/blog/rescue_action_in_public-local_request-and-how-to-configure-local_request.md"
---

# Configure local_request

How does Rails handle exceptions? Rails exception handling depends on two
factors and we are going to discuss both of them here.

- Author: Neeraj Singh
- Published: February 5, 2009
- Categories: Rails

How does Rails handle exceptions ?

Rails exception handling depends on two factors and we are going to discuss both
of them here.

```ruby
# ~/lib/action_controller/rescue.rb
if consider_all_requests_local || local_request?
  rescue_action_locally(exception)
else
  rescue_action_in_public(exception)
end
```

When exceptions are handled by `rescue_action_locally` then we get to see the
page with stacktrace. When exceptions are handled by `rescue_action_in_public`,
we get to see the `public/500.html` or an error page matching the error code.

As you can see Rails uses two different methods `consider_all_requests_local`
and `local_request?` to decide how exception should be handled.

## Method consider_all_requests_local

`consider_all_requests_local` is a class level variable for
`ActionController::Base` . We hardly pay attention to it but it is configured
through files residing in `config/environments`

```ruby
# config/environments/development.rb
config.action_controller.consider_all_requests_local = true

# config/environments/production.rb
config.action_controller.consider_all_requests_local = false
```

As you can see in development environment all the requests are considered local.

## I have overridden the method local_request? but I am still not able to see public page when exception is raised.

That is a common question I see in the mailing list. As you can see the
condition to decide how to handle exception is

```ruby
if consider_all_requests_local || local_request?
```

In development environment `consider_all_requests_local` is always true as I
showed before. Since one of the conditions is true Rails always handles the
exception `using rescue_action_locally` .

## I am running in production mode but I am still not able to see public/500.html page when I get exception at http://localhost:3000.

Same issue. In this case you are running in production mode so
`consider_all_requests_local` is `false` but local_request? is still true
because of localhost.

## I want local_request? to be environment dependent

Recently I started using hoptoad and I needed to test how hoptoad will handle
exception in production mode. However without any change local_request? was
always returning true for `http://localhost:30000` .

Then I stick following file under `config/initializers`

```ruby
# config/initializers/local_request_override.rb
module CustomRescue
  def local_request?
    return false if Rails.env.production? || Rails.env.staging?
    super
  end
end

ActionController::Base.class_eval do
  include CustomRescue
end
```

Now all request in production or in staging mode are treated as NOT local.

Now in both `staging` and `production` mode I get to see 500.html page even if I
am accessing the application from `http://localhost:3000` .

## Links

- [Human page](https://www.bigbinary.com/blog/rescue_action_in_public-local_request-and-how-to-configure-local_request)