HTTP status exception¶ ↑

This simple plugin will register exception classes for all HTTP status. These exceptions can then be raised from your controllers, after which a response will be send back to the client with the desired HTTP status, possible with some other content.

You can use this plugin to access control mechanisms. You can simply raise a HTTPStatus::Forbidden if a user is not allowed to perform a certain action. A nice looking error page will be the result. See the project wiki (github.com/wvanbergen/http_status_exceptions/wiki) for additional documentation.

This plugin only works with Rails 3. Version 0.2.1 of this plugin is compatible with Rails 2. The code for this version can be found in the rails2 branch: github.com/wvanbergen/http_status_exceptions/tree/rails2.

Installation is simple. Simply add the gem to the configuration in your Gemfile:

# Gemfile
gem 'http_status_exceptions'

Run bundle install to make sure to have the gem included in your bundle.

You can modify where HTTP status exception looks for its template files like so:

class ApplicationController < ActionController::Base
  ...
  HTTPStatus::Base.template_path = 'path_to/http_status_templates'
end

You can also modify which layout is used when rendering a template by setting the template_layout:

class ApplicationController < ActionController::Base
  ...
  HTTPStatus::Base.template_layout = 'exception'
end

If you don’t set a template_layout the current layout for the requested action will be used.

class BlogController < ApplicationController

  def destroy
    raise HTTPStatus::Forbidden, 'You cannot delete blogs!' unless current_user.can_delete_blogs?
    @blog.destroy
  end
end

By default, this will return an empty response with the “forbidden” status code (403). If you want to add content to the response as well, create the following view: shared/http_status/forbidden.html.erb. You can use the @exception-object in your view:

<h1>Forbidden</h1>
<p> <%= h(@exception.message) %> </p>
<hr />
<p>HTTP status code <small> <%= @exception.status_code %>: <%= @exception.status.to_s.humanize %></small></p>

The response will only be sent if the request format is HTML because of the name of the view file. In theory you could make a response for XML requests as well by using shared/http_status/forbidden.xml.builder as filename