Rails error handling for the view

notes.rb

# sources:
# http://www.igodigital.com/blog/blog/notes-on-cyber-weekend-targeted-email-campaigns/custom-error-handling-in-rails-303
# To test in dev, use the production setting below
# config/environments/development.rb
config.consider_all_requests_local = false

# delete the 404.html, and 500.html files.
# generate an error controller
`rails g controller Errors 404 500`

class ApplicationController < ActionController::Base
  unless config.consider_all_requests_local
    rescue_from Exception, :with => :render_error
    rescue_from ActiveRecord::RecordNotFound, :with => :render_not_found
    rescue_from ActionController::RoutingError, :with => :render_not_found
    rescue_from ActionController::UnknownController, :with => :render_not_found
    # customize these as much as you want, ie, different for every error or all the same
    rescue_from ActionController::UnknownAction, :with => :render_not_found
  end
  
  private
  
  def render_not_found(exception)
    render :template => "/errors/404.html.erb", :status => 404
  end
  
  def render_error(exception)
    # you can insert logic in here too to log errors
    # or get more error info and use different templates
    render :template => "/errors/500.html.erb", :status => 500
  end
end

# . In Rails 3, rescue_from ActionController::RoutingError is actually broken. 
# It will be fixed in Rails 3.1, but until then, we have a little bit of a hack to work around this problem.
# let's just make a route that will catch all the ones 
# that don't get found in our current routes.rb file. 
# At the bottom of config/routes.rb, add this:

match '*a', :to => 'errors#404'

# The *a signifies params[:a] and will match any route requested.

# For other ways to render errors, look into render_optional_error_file
# If executing queries from views, you'll only get a general error instead of record not found