Module: Net::IMAP::Config::AttrInheritance

Included in:
Net::IMAP::Config
Defined in:
lib/net/imap/config/attr_inheritance.rb

Overview

NOTE: The public methods on this module are part of the stable

public API of Net::IMAP::Config. But the module itself is an internal implementation detail, with no guarantee of backward compatibility.

attr_accessor methods will delegate to their #parent when the local value does not contain an override. Inheritance forms a singly linked list, so lookup will be O(n) on the number of ancestors. In practice, the ancestor chain is not expected to be long. Without customization, it is only three deep:

IMAP#config → Config.global → Config.default

When creating a client with the config keyword, for example to use the appropriate defaults for an application or a library while still relying on global for configuration of debug or logger, most likely the ancestor chain is still only four deep:

IMAP#config → alternate defaults → Config.global → Config.default

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#parent ⇒ Object (readonly)

The parent Config object



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# File 'lib/net/imap/config/attr_inheritance.rb', line 46

def parent
  @parent
end

Class Method Details

.attr_accessor(name) ⇒ Object

:nodoc: internal API



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# File 'lib/net/imap/config/attr_inheritance.rb', line 39

def self.attr_accessor(name) # :nodoc: internal API
  module_eval <<~RUBY, __FILE__, __LINE__ + 1
    def #{name}; (val = super) == INHERITED ? parent&.#{name} : val end
  RUBY
end

Instance Method Details

#inherited?(*attrs) ⇒ Boolean

:call-seq:

inherited?(attr)   -> true or false
inherited?(*attrs) -> true or false
inherited?         -> true or false

Returns true if attr is inherited from #parent and not overridden by this config.

When multiple attrs are given, returns true if all of them are inherited, or false if any of them are overriden. When no attrs are given, returns true if all attributes are inherited, or false if any attribute is overriden.

Related: #overrides?

Returns:

  • (Boolean) 


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# File 'lib/net/imap/config/attr_inheritance.rb', line 71

def inherited?(*attrs)
  attrs = data.members if attrs.empty?
  attrs.all? { data[_1] == INHERITED }
end

#inherits_defaults?(*attrs) ⇒ Boolean

:call-seq:

inherits_defaults?(*attrs) -> true | Rational | nil | false

Returns whether all attrs are inherited from a default config. When no attrs are given, returns whether all attributes are inherited from a default config.

Returns true when all attributes inherit from Config.default, the version number (as a Rational) when all attributes inherit from a versioned default (see Config@Versioned+defaults), nil if any attributes inherit from Config.global overrides (but not from non-global ancestors), or false when any attributes have been overridden by self or an ancestor (besides global or default configs),

Related: #overrides?

Returns:

  • (Boolean) 


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# File 'lib/net/imap/config/attr_inheritance.rb', line 92

def inherits_defaults?(*attrs)
  if equal?(Config.default)
    true
  elsif equal?(Config.global)
    true if inherited?(*attrs)
  elsif (v = AttrVersionDefaults::VERSIONS.find { equal? Config[_1] })
    attrs  = DEFAULT_TO_INHERIT if attrs.empty?
    attrs &= DEFAULT_TO_INHERIT
    (attrs.empty? || parent.inherits_defaults?(*attrs)) && v
  else
    inherited?(*attrs) && parent.inherits_defaults?(*attrs)
  end
end

#initialize(parent = nil) ⇒ Object

:notnew:



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# File 'lib/net/imap/config/attr_inheritance.rb', line 48

def initialize(parent = nil) # :notnew:
  super()
  @parent = Config[parent]
  reset
end

#new(**attrs) ⇒ Object

Creates a new config, which inherits from self.



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# File 'lib/net/imap/config/attr_inheritance.rb', line 55

def new(**attrs) self.class.new(self, **attrs) end

#overrides?(*attrs) ⇒ Boolean

:call-seq:

overrides?(attr)   -> true or false
overrides?(*attrs) -> true or false
overrides?         -> true or false

Returns true if attr is defined on this config and not inherited from #parent.

When multiple attrs are given, returns true if any of them are defined on self. When no attrs are given, returns true if any attribute is overriden.

Related: #inherited?

Returns:

  • (Boolean) 


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# File 'lib/net/imap/config/attr_inheritance.rb', line 119

def overrides?(*attrs)
  attrs = data.members if attrs.empty?
  attrs.any? { data[_1] != INHERITED }
end

#reset(attr = nil) ⇒ Object

:call-seq:

reset -> self
reset(attr) -> attribute value

Resets an attr to inherit from the #parent config.

When attr is nil or not given, all attributes are reset.



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# File 'lib/net/imap/config/attr_inheritance.rb', line 131

def reset(attr = nil)
  if attr.nil?
    data.members.each do |attr| data[attr] = INHERITED end
    self
  elsif inherited?(attr)
    nil
  else
    old, data[attr] = data[attr], INHERITED
    old
  end
end