Class: Configurable::Config

Inherits:
Object show all
Defined in:
lib/configurable/config.rb

Overview

Configs are used by ConfigHash to determine how to delegate read/write operations to a receiver. Configs also track metadata related to their presentation in various contexts.

Direct Known Subclasses

NestConfig

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(reader, writer = "#{reader}=", default = nil, attributes = {}, init = true, dup = nil) ⇒ Config

Initializes a new Config.



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# File 'lib/configurable/config.rb', line 32

def initialize(reader, writer="#{reader}=", default=nil, attributes={}, init=true, dup=nil)
  self.reader = reader
  self.writer = writer
  @default = default
  @attributes = attributes
  @init = init
  @dup = dup.nil? ? Config.duplicable_value?(default) : dup
end

Instance Attribute Details

#attributes ⇒ Object (readonly)

An hash of metadata for self, often used to indicate how a config is presented in different contexts (ex on the command line, in a web form, or a desktop app).



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# File 'lib/configurable/config.rb', line 29

def attributes
  @attributes
end

#reader ⇒ Object

The reader method called on a receiver during get



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# File 'lib/configurable/config.rb', line 21

def reader
  @reader
end

#writer ⇒ Object

The writer method called on a receiver during set



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# File 'lib/configurable/config.rb', line 24

def writer
  @writer
end

Class Method Details

.duplicable_value?(value) ⇒ Boolean

Determines if the value is duplicable. Non-duplicable values include nil, true, false, Symbol, Numeric, Method, Module, and any object that does not respond to dup.

Returns:

  • (Boolean) 


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# File 'lib/configurable/config.rb', line 12

def duplicable_value?(value)
  case value
  when nil, true, false, Symbol, Numeric, Method, Module then false
  else value.respond_to?(:dup)
  end
end

Instance Method Details

#[](key, default = nil) ⇒ Object

Returns the value for the specified attribute, or default if the attribute is unspecified.



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# File 'lib/configurable/config.rb', line 50

def [](key, default=nil)
  attributes.has_key?(key) ? attributes[key] : default
end

#default(duplicate = true) ⇒ Object

Returns the default value. If duplicate is specified and the default may be duplicated (see Config.duplicable_value?) then a duplicate of the default is returned.



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# File 'lib/configurable/config.rb', line 44

def default(duplicate=true)
  duplicate && @dup ? @default.dup : @default
end

#get(receiver) ⇒ Object

Calls reader on the receiver and returns the result.



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# File 'lib/configurable/config.rb', line 55

def get(receiver)
  receiver.send(reader)
end

#init(receiver) ⇒ Object

Sets the default value on the receiver. Normally this method is only called during Configurable#initialize_config, and only then when init? returns true.



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# File 'lib/configurable/config.rb', line 67

def init(receiver)
  receiver.send(writer, default)
end

#init? ⇒ Boolean

Returns true or false as specified in new. True indicates that this delegate is allowed to initialize values on the receiver during Configurable#initialize_config.

Returns:

  • (Boolean) 


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# File 'lib/configurable/config.rb', line 74

def init?
  @init
end

#inspect ⇒ Object

Returns an inspection string.



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# File 'lib/configurable/config.rb', line 79

def inspect
  "#<#{self.class}:#{object_id} reader=#{reader} writer=#{writer} default=#{default.inspect} >"
end

#set(receiver, value) ⇒ Object

Calls writer on the receiver with the value.



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# File 'lib/configurable/config.rb', line 60

def set(receiver, value)
  receiver.send(writer, value)
end