Class: Hypertube::Core::Handler::SetInstanceFieldHandler

Inherits:
AbstractHandler show all
Defined in:
lib/hypertube-ruby-sdk/core/handler/set_instance_field_handler.rb

Instance Method Summary collapse

Methods inherited from AbstractHandler

#handle_command, #validate

Constructor Details

#initialize ⇒ SetInstanceFieldHandler

Returns a new instance of SetInstanceFieldHandler.



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# File 'lib/hypertube-ruby-sdk/core/handler/set_instance_field_handler.rb', line 9

def initialize
  @required_parameters_count = 3
end

Instance Method Details

#process(command) ⇒ Object 



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# File 'lib/hypertube-ruby-sdk/core/handler/set_instance_field_handler.rb', line 13

def process(command)
  set_instance_field(command)
end

#set_instance_field(command) ⇒ Object 



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# File 'lib/hypertube-ruby-sdk/core/handler/set_instance_field_handler.rb', line 17

def set_instance_field(command)
  validate(command, @required_parameters_count, self.class.name)

  instance = command.payload[0]
  field_name = command.payload[1].to_s
  new_value = command.payload[2]

  field = field_name.start_with?('@') ? field_name : "@#{field_name}"
  field_defined = begin
    instance.instance_variable_defined?(field)
  rescue NameError
    false
  end

  unless field_defined
    fields = instance.instance_variables

    value_type = new_value.nil? ? 'null' : new_value.class.name
    class_name = instance.class.name
    message = "Failed to set value of type #{value_type} for #{field_name} in class #{class_name}.\nAvailable public instance variables:\n"
    fields.each { |field_iter| message += "#{field_iter}\n" }
    raise ArgumentError, message
  end

  instance.instance_variable_set(field, new_value)
  instance
end