Methods
Instance Public methods
rescue_from(*klasses, &block)
Link
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
Exceptions raised inside exception handlers are not propagated up.
# File activesupport/lib/active_support/rescuable.rb, line 51 def rescue_from(*klasses, &block) options = klasses.extract_options! unless options.has_key?(:with) if block_given? options[:with] = block else raise ArgumentError, "Need a handler. Supply an options hash that has a :with key as the last argument." end end klasses.each do |klass| key = if klass.is_a?(Class) && klass <= Exception klass.name elsif klass.is_a?(String) klass else raise ArgumentError, "#{klass} is neither an Exception nor a String" end # put the new handler at the end because the list is read in reverse self.rescue_handlers += [[key, options[:with]]] end end