Module: OFlow::HasErrorHandler

Included in:
Env, Flow, Task
Defined in:
lib/oflow/haserrorhandler.rb

Overview

Provides functionality to find an error handler Task which is how error are handled in the system. Each Flow or Task can have a different error handler. If a Flow does not have an error handler the error bubbles up to the next Flow until an error handler is found.

Instance Method Summary collapse

Instance Method Details

#error_handler ⇒ Task|nil

Returns an error handler Task by checking for an @error_handler variable, then looking for a Task with a base name of :error in itself or any of the containing Flows.

Returns:

  • (Task|nil) —

    Task to handle errors



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# File 'lib/oflow/haserrorhandler.rb', line 14

def error_handler()
  return @error_handler if instance_variable_defined?(:@error_handler) && !@error_handler.nil?
  if instance_variable_defined?(:@flow)
    if @flow.respond_to?(:find_task)
      eh = @flow.find_task(:error)
      return eh unless eh.nil?
    end
    if @flow.respond_to?(:error_handler)
      eh = @flow.error_handler()
      return eh unless eh.nil?
    end
  end      
  nil
end

#error_handler=(t) ⇒ Object

Sets avaliable for handling errors.

Parameters:

  • t (Task|nil) —

    Task for handling error or nil to unset



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# File 'lib/oflow/haserrorhandler.rb', line 31

def error_handler=(t)
  @error_handler = t
end

#handle_error(e) ⇒ Object

Handles errors by putting a requestion on the error handler Task.

Parameters:

  • e (Exception) —

    error to handle



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# File 'lib/oflow/haserrorhandler.rb', line 37

def handle_error(e)
  handler = error_handler()
  unless handler.nil?
    handler.receive(nil, Box.new([e, full_name()]))
  else
    puts "** [#{full_name()}] #{e.class}: #{e.message}"
    e.backtrace.each { |line| puts "    #{line}" }
  end
end