Module: NameMagic::ClassMethods

Defined in:
lib/y_support/name_magic/class_methods.rb

Instance Method Summary collapse

Instance Method Details

#instance_names(option = false) ⇒ Object

Presents the instance names. Takes one optional argument, same as #instances method. Unnamed instances are completely disregarded.



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# File 'lib/y_support/name_magic/class_methods.rb', line 27

def instance_names option=false
  instances( option ).names( false )
end

#instances(option = false) ⇒ Object

Presents the instances registered by the namespace. Takes one optional argument. If set to false, the method returns all the instances registered by the namespace. If set to true (default), only returns those instances registered by the namespace, which are of the exact same class as the method’s receiver. Example:

class Animal; include NameMagic end
Cat, Dog = Class.new( Animal ), Class.new( Animal )
Spot = Dog.new
Livia = Cat.new
Animal.instances #=> returns 2 instances
Dog.instances #=> returns 1 instance
Dog.instances( false ) #=> returns 2 instances of the namespace Animal



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# File 'lib/y_support/name_magic/class_methods.rb', line 18

def instances option=false
  const_magic
  return __instances__.keys if option
  __instances__.keys.select { |i| i.kind_of? self }
end

#new(*args, &block) ⇒ Object

In addition the ability to name objects upon constant assignment, as common with eg. Class instances, NameMagic redefines class method #new so that it swallows the named argument :name (alias :ɴ), and takes care of naming the instance accordingly. Also, :name_avid named argument mey be supplied, which makes the naming avid (able to overwrite the name already in use by another object) if set to true.



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# File 'lib/y_support/name_magic/class_methods.rb', line 38

def new *args, &block
  oo = args[-1].is_a?( Hash ) ? args.pop : {} # extract hash
  nm = if oo[:name] then oo.delete :name       # consume :name if supplied
       elsif oo[:ɴ] then oo.delete :ɴ          # consume :ɴ if supplied
       else nil end
  avid = oo[:name_avid] ? oo.delete( :name_avid ) : false # => true/false
  # Avoid overwriting existing names unless avid:
  fail NameError, "#{self} instance #{nm} already exists!" if
    __instances__.keys.include? nm unless avid
  args << oo unless oo.empty?    # prepare the arguments
  new_before_name_magic( *args, &block ).tap do |new_inst| # instantiate
    __instances__.update new_inst => nil # Instance is created unnamed...
    namespace.new_instance_closure.tap { |λ|
      λ.( new_inst ) if λ
      if nm then # name has been supplied, we can name the instance:
        avid ? new_inst.name!( nm ) : new_inst.name = nm
      else # name hasn't been supplied, making the instance avid:
        __avid_instances__ << new_inst
      end
    }
  end
end

#new!(*args, &block) ⇒ Object

Calls #new in avid mode (name_avid: true); see #new method for avid mode explanation.



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# File 'lib/y_support/name_magic/class_methods.rb', line 64

def new! *args, &block
  oo = args[-1].is_a?( Hash ) ? args.pop : {} # extract options
  new *args, oo.update( name_avid: true ), &block
end