sonic-pi

ActiveSupport::Rescuable::ClassMethods#rescue_from

Rescue exceptions raised in controller actions.

<tt>rescue_from</tt> receives a series of exception classes or class
names, and a trailing <tt>:with</tt> 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 <tt>exception.is_a?(klass)</tt> 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.

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