Module: Class::ClassExtensions

Included in:
Class
Defined in:
lib/ruckus/extensions/class.rb

Constant Summary collapse

EMPTY_INHERITABLE_ATTRIBUTES =

Prevent this constant from being created multiple times

{}.freeze

Instance Method Summary collapse

Instance Method Details

#alias_cmethod(to, from) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 22

def alias_cmethod(to, from)
    # XXX not used
    (class << self;self;end).class_eval {
        define_method to do |*args|
            send(from, *args)
        end
    }
end

#class_inheritable_accessor(*syms) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 102

def class_inheritable_accessor(*syms)
    class_inheritable_reader(*syms)
    class_inheritable_writer(*syms)
end

#class_inheritable_array(*syms) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 107

def class_inheritable_array(*syms)
    class_inheritable_reader(*syms)
    class_inheritable_array_writer(*syms)
end

#class_inheritable_array_writer(*syms) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 68

def class_inheritable_array_writer(*syms)
     options = syms.extract_options!
     syms.each do |sym|
         class_eval <<-EOS
  def self.#{sym}=(obj)
    write_inheritable_array(:#{sym}, obj)
  end

  #{"
  def #{sym}=(obj)
    self.class.#{sym} = obj
  end
  " unless options[:instance_writer] == false }
EOS
    end
end

#class_inheritable_hash(*syms) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 112

def class_inheritable_hash(*syms)
    class_inheritable_reader(*syms)
    class_inheritable_hash_writer(*syms)
end

#class_inheritable_hash_writer(*syms) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 85

def class_inheritable_hash_writer(*syms)
    options = syms.extract_options!
    syms.each do |sym|
        class_eval <<-EOS
def self.#{sym}=(obj)
  write_inheritable_hash(:#{sym}, obj)
end

#{"
def #{sym}=(obj)
  self.class.#{sym} = obj
end
" unless options[:instance_writer] == false }
      EOS
    end
end

#class_inheritable_reader(*syms) ⇒ Object

Allows attributes to be shared within an inheritance hierarchy, but where each descendant gets a copy of their parents’ attributes, instead of just a pointer to the same. This means that the child can add elements to, for example, an array without those additions being shared with either their parent, siblings, or children, which is unlike the regular class-level attributes that are shared across the entire hierarchy.



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# File 'lib/ruckus/extensions/class.rb', line 36

def class_inheritable_reader(*syms)
     syms.each do |sym|
         next if sym.is_a?(Hash)
         class_eval <<-EOS
def self.#{sym}
    read_inheritable_attribute(:#{sym})
end

def #{sym}
    self.class.#{sym}
end
EOS
      end
end

#class_inheritable_writer(*syms) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 51

def class_inheritable_writer(*syms)
     options = syms.extract_options!
     syms.each do |sym|
         class_eval <<-EOS
 def self.#{sym}=(obj)
   write_inheritable_attribute(:#{sym}, obj)
 end

 #{"
 def #{sym}=(obj)
   self.class.#{sym} = obj
 end
 " unless options[:instance_writer] == false }
EOS
   end
end

#inheritable_attributes ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 117

def inheritable_attributes
    @inheritable_attributes ||= EMPTY_INHERITABLE_ATTRIBUTES
end

#inherits_from?(klass) ⇒ Boolean

Also crazy that this isn’t in the library

Returns:

  • (Boolean) 


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# File 'lib/ruckus/extensions/class.rb', line 4

def inherits_from?(klass)
    return true if self == klass
    return true if self.superclass == klass
    return false if self.superclass == Object

    rec = lambda do |x|
        if x == Object
            false
        elsif x == klass
            true
        else
            rec.call(x.superclass)
        end
    end

    rec.call(self)
end

#read_inheritable_attribute(key) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 138

def read_inheritable_attribute(key)
    inheritable_attributes[key]
end

#reset_inheritable_attributes ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 142

def reset_inheritable_attributes
    @inheritable_attributes = EMPTY_INHERITABLE_ATTRIBUTES
end

#write_inheritable_array(key, elements) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 128

def write_inheritable_array(key, elements)
    write_inheritable_attribute(key, []) if read_inheritable_attribute(key).nil?
    write_inheritable_attribute(key, read_inheritable_attribute(key) + elements)
end

#write_inheritable_attribute(key, value) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 121

def write_inheritable_attribute(key, value)
    if inheritable_attributes.equal?(EMPTY_INHERITABLE_ATTRIBUTES)
        @inheritable_attributes = {}
    end
    inheritable_attributes[key] = value
end

#write_inheritable_hash(key, hash) ⇒ Object 



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# File 'lib/ruckus/extensions/class.rb', line 133

def write_inheritable_hash(key, hash)
    write_inheritable_attribute(key, {}) if read_inheritable_attribute(key).nil?
    write_inheritable_attribute(key, read_inheritable_attribute(key).merge(hash))
end