Class: Clamp::Attribute::Instance

Inherits:
Object
  • Object
show all
Defined in:
lib/clamp/attribute/instance.rb

Overview

Represents an option/parameter of a Clamp::Command instance.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(attribute, command) ⇒ Instance

Returns a new instance of Instance.



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# File 'lib/clamp/attribute/instance.rb', line 8

def initialize(attribute, command)
  @attribute = attribute
  @command = command
end

Instance Attribute Details

#attribute ⇒ Object (readonly)

Returns the value of attribute attribute.



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# File 'lib/clamp/attribute/instance.rb', line 13

def attribute
  @attribute
end

#command ⇒ Object (readonly)

Returns the value of attribute command.



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# File 'lib/clamp/attribute/instance.rb', line 13

def command
  @command
end

Instance Method Details

#_read ⇒ Object

default implementation of read_method



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# File 'lib/clamp/attribute/instance.rb', line 34

def _read
  if self.defined?
    get
  else
    default
  end
end

#_write(value) ⇒ Object

default implementation of write_method



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# File 'lib/clamp/attribute/instance.rb', line 43

def _write(value)
  if attribute.multivalued?
    current_values = get || []
    set(current_values + [value])
  else
    set(value)
  end
end

#default ⇒ Object 



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# File 'lib/clamp/attribute/instance.rb', line 29

def default
  command.send(attribute.default_method)
end

#default_from_environment ⇒ Object 



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# File 'lib/clamp/attribute/instance.rb', line 60

def default_from_environment
  return if self.defined?
  return if attribute.environment_variable.nil?
  return unless ENV.has_key?(attribute.environment_variable)
  # Set the parameter value if it's environment variable is present
  value = ENV[attribute.environment_variable]
  begin
    write(value)
  rescue ArgumentError => e
    command.send(:signal_usage_error, "$#{attribute.environment_variable}: #{e.message}")
  end
end

#defined? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/clamp/attribute/instance.rb', line 15

def defined?
  command.instance_variable_defined?(attribute.ivar_name)
end

#get ⇒ Object

get value directly



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# File 'lib/clamp/attribute/instance.rb', line 20

def get
  command.instance_variable_get(attribute.ivar_name)
end

#read ⇒ Object 



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# File 'lib/clamp/attribute/instance.rb', line 52

def read
  command.send(attribute.read_method)
end

#set(value) ⇒ Object

set value directly



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# File 'lib/clamp/attribute/instance.rb', line 25

def set(value)
  command.instance_variable_set(attribute.ivar_name, value)
end

#write(value) ⇒ Object 



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# File 'lib/clamp/attribute/instance.rb', line 56

def write(value)
  command.send(attribute.write_method, value)
end