Method: Grape::DSL::RequestResponse::ClassMethods#rescue_from

Defined in:
lib/grape/dsl/request_response.rb

#rescue_from(*exception_classes, **options) ⇒ Object

Allows you to rescue certain exceptions that occur to return a grape error rather than raising all the way to the server level.

Examples:

Rescue from custom exceptions

class ExampleAPI < Grape::API
  class CustomError < StandardError; end

  rescue_from CustomError
end

Parameters:

  • exception_classes (Array) —

    A list of classes that you want to rescue, or the symbol :all to rescue from all exceptions.

  • block (Block) —

    Execution block to handle the given exception.

  • options (Hash) —

    Options for the rescue usage.

  • handler (Proc) —

    Execution proc to handle the given exception as an alternative to passing a block.

Options Hash (**options):

  • :backtrace (Boolean) —

    Include a backtrace in the rescue response.

  • :rescue_subclasses (Boolean) —

    Also rescue subclasses of exception classes



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# File 'lib/grape/dsl/request_response.rb', line 100

def rescue_from(*args, &block)
  if args.last.is_a?(Proc)
    handler = args.pop
  elsif block_given?
    handler = block
  end

  options = args.extract_options!
  if block_given? && options.key?(:with)
    raise ArgumentError, 'both :with option and block cannot be passed'
  end
  handler ||= extract_with(options)

  if args.include?(:all)
    namespace_inheritable(:rescue_all, true)
    namespace_inheritable :all_rescue_handler, handler
  elsif args.include?(:grape_exceptions)
    namespace_inheritable(:rescue_all, true)
    namespace_inheritable(:rescue_grape_exceptions, true)
  else
    handler_type =
      case options[:rescue_subclasses]
      when nil, true
        :rescue_handlers
      else
        :base_only_rescue_handlers
      end

    namespace_reverse_stackable handler_type, Hash[args.map { |arg| [arg, handler] }]
  end

  namespace_stackable(:rescue_options, options)
end