Class: Module

Inherits:
Object show all
Defined in:
lib/active_support/dependencies.rb,
lib/active_support/core_ext/module/loading.rb,
lib/active_support/core_ext/module/inclusion.rb,
lib/active_support/core_ext/module/delegation.rb,
lib/active_support/core_ext/module/introspection.rb,
lib/active_support/core_ext/module/attribute_accessors.rb

Overview

Extends the module object with module and instance accessors for class attributes, just like the native attr* accessors for instance attributes.

Instance Method Summary collapse

Instance Method Details

#as_load_path ⇒ Object 



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# File 'lib/active_support/core_ext/module/loading.rb', line 2

def as_load_path
  if self == Object || self == Kernel
    ''
  elsif is_a? Class
    parent == self ? '' : parent.as_load_path
  else
    name.split('::').collect do |word|
      word.underscore
    end * '/'
  end
end

#const_missing(class_id) ⇒ Object

Use const_missing to autoload associations so we don’t have to require_association when using single-table inheritance.



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# File 'lib/active_support/dependencies.rb', line 94

def const_missing(class_id)
  file_name = class_id.to_s.demodulize.underscore
  file_path = as_load_path.empty? ? file_name : "#{as_load_path}/#{file_name}"
  begin
    require_dependency(file_path)
    brief_name = self == Object ? '' : "#{name}::"
    raise NameError.new("uninitialized constant #{brief_name}#{class_id}") unless const_defined?(class_id)
    return const_get(class_id)
  rescue MissingSourceFile => e
    # Re-raise the error if it does not concern the file we were trying to load.
    raise unless e.is_missing? file_path
    
    # Look for a directory in the load path that we ought to load.
    if $LOAD_PATH.any? { |base| File.directory? "#{base}/#{file_path}" }
      mod = Module.new
      const_set class_id, mod # Create the new module
      return mod
    end
    
    # Attempt to access the name from the parent, unless we don't have a valid
    # parent, or the constant is already defined in the parent. If the latter
    # is the case, then we are being queried via self::class_id, and we should
    # avoid returning the constant from the parent if possible.
    if parent && parent != self && ! parents.any? { |p| p.const_defined?(class_id) }
      suppress(NameError) do
        return parent.send(:const_missing, class_id)
      end
    end
    
    raise NameError.new("uninitialized constant #{class_id}").copy_blame!(e)
  end
end

#delegate(*methods) ⇒ Object 



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# File 'lib/active_support/core_ext/module/delegation.rb', line 2

def delegate(*methods)
  options = methods.pop
  unless options.is_a?(Hash) && to = options[:to]
    raise ArgumentError, "Delegation needs a target. Supply an options hash with a :to key"
  end

  methods.each do |method|
    module_eval(<<-EOS, "(__DELEGATION__)", 1)
      def #{method}(*args, &block)
        #{to}.__send__(#{method.inspect}, *args, &block)
      end
    EOS
  end
end

#included_in_classes ⇒ Object 



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# File 'lib/active_support/core_ext/module/inclusion.rb', line 2

def included_in_classes
  classes = []
  ObjectSpace.each_object(Class) { |k| classes << k if k.included_modules.include?(self) }

  classes.reverse.inject([]) do |unique_classes, klass| 
    unique_classes << klass unless unique_classes.collect { |k| k.to_s }.include?(klass.to_s)
    unique_classes
  end
end

#mattr_accessor(*syms) ⇒ Object 



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# File 'lib/active_support/core_ext/module/attribute_accessors.rb', line 40

def mattr_accessor(*syms)
  mattr_reader(*syms)
  mattr_writer(*syms)
end

#mattr_reader(*syms) ⇒ Object

:nodoc:



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# File 'lib/active_support/core_ext/module/attribute_accessors.rb', line 4

def mattr_reader(*syms)
  syms.each do |sym|
    class_eval(<<-EOS, __FILE__, __LINE__)
      unless defined? @@#{sym}
        @@#{sym} = nil
      end
      
      def self.#{sym}
        @@#{sym}
      end

      def #{sym}
        @@#{sym}
      end
    EOS
  end
end

#mattr_writer(*syms) ⇒ Object 



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# File 'lib/active_support/core_ext/module/attribute_accessors.rb', line 22

def mattr_writer(*syms)
  syms.each do |sym|
    class_eval(<<-EOS, __FILE__, __LINE__)
      unless defined? @@#{sym}
        @@#{sym} = nil
      end
      
      def self.#{sym}=(obj)
        @@#{sym} = obj
      end

      def #{sym}=(obj)
        @@#{sym} = obj
      end
    EOS
  end
end

#parent ⇒ Object

Return the module which contains this one; if this is a root module, such as ::MyModule, then Object is returned.



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# File 'lib/active_support/core_ext/module/introspection.rb', line 4

def parent
  parent_name = name.split('::')[0..-2] * '::'
  parent_name.empty? ? Object : parent_name.constantize
end

#parents ⇒ Object

Return all the parents of this module, ordered from nested outwards. The receiver is not contained within the result.



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# File 'lib/active_support/core_ext/module/introspection.rb', line 11

def parents
  parents = []
  parts = name.split('::')[0..-2]
  until parts.empty?
    parents << (parts * '::').constantize
    parts.pop
  end
  parents << Object unless parents.include? Object
  parents
end

#rails_original_const_missing ⇒ Object

Rename the original handler so we can chain it to the new one



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# File 'lib/active_support/dependencies.rb', line 90

alias :rails_original_const_missing :const_missing