Methods
Instance Public methods
Rescue exceptions raised in controller actions.
rescue_from receives a series of exception classes or class names, and a trailing :with option with the name of a method or a Proc object to be called to handle them. Alternatively a block can be given.
Handlers that take one argument will be called with the exception, so that the exception can be inspected when dealing with it.
Handlers are inherited. They are searched from right to left, from bottom to top, and up the hierarchy. The handler of the first class for which exception.is_a?(klass) holds true is the one invoked, if any.
class ApplicationController < ActionController::Base rescue_from User::NotAuthorized, :with => :deny_access # self defined exception rescue_from ActiveRecord::RecordInvalid, :with => :show_errors rescue_from 'MyAppError::Base' do |exception| render :xml => exception, :status => 500 end protected def deny_access ... end def show_errors(exception) exception.record.new_record? ? ... end end
# File activesupport/lib/active_support/rescuable.rb, line 51 51: def rescue_from(*klasses, &block) 52: options = klasses.extract_options! 53: 54: unless options.has_key?(:with) 55: if block_given? 56: options[:with] = block 57: else 58: raise ArgumentError, "Need a handler. Supply an options hash that has a :with key as the last argument." 59: end 60: end 61: 62: klasses.each do |klass| 63: key = if klass.is_a?(Class) && klass <= Exception 64: klass.name 65: elsif klass.is_a?(String) 66: klass 67: else 68: raise ArgumentError, "#{klass} is neither an Exception nor a String" 69: end 70: 71: # put the new handler at the end because the list is read in reverse 72: self.rescue_handlers += [[key, options[:with]]] 73: end 74: end