module Webgen::ExtensionManager

Create a new extension manager.

# File lib/webgen/extension_manager.rb, line 19
def initialize
  @extensions = {}
end

Register a new extension.

*Note* that this method has to be implemented by classes that include this module. It should register one or more names for an extension object by associating the names with the extension object data (should be an object that responds at least to :object) via the @extensions hash.

The simplest way to achieve this is to use the do_register method.

# File lib/webgen/extension_manager.rb, line 36
def register(klass, options = {}, &block)
  raise NotImplementedError
end

Return true if an extension with the given name has been registered with this manager class.

# File lib/webgen/extension_manager.rb, line 109
def registered?(name)
  @extensions.has_key?(name.to_sym)
end

Return the meta data of all extensions registered with this manager class.

# File lib/webgen/extension_manager.rb, line 114
def registered_extensions
  @extensions.dup
end

Automatically perform the necessary steps to register the extension klass. This involves normalization of the class name and associating the extension name (derived from the class name if not set via the key :name in the options hash) with the extension.

The parameter klass can either be a String or a Class specifying the class that should be registered.

The parameter options allows to associate additional information with an extension. The only recognized key is :name (for the extension name). All other keys are ignored and can/should be used by the extension manager class itself.

The parameter allow_block specifies whether the extension manager allows blocks as extensions. If this parameter is true and a block is provided, the klass parameter is not used!

Returns the (possibly automatically generated) name for the extension.

# File lib/webgen/extension_manager.rb, line 56
def do_register(klass, options = {}, allow_block = true, &block)
  if !allow_block && block_given?
    raise ArgumentError, "The extension manager '#{self.class.name}' does not support blocks on #register"
  end
  klass, klass_name = normalize_class_name(klass, !block_given?)
  name = (options[:name] || Webgen::Utils.snake_case(klass_name)).to_sym
  @extensions[name] = OpenStruct.new(:object => (block_given? ? block : klass))
  name
end

Return the extension data for the extension name.

# File lib/webgen/extension_manager.rb, line 95
def ext_data(name)
  @extensions[name.to_sym]
end

Return the registered object for the extension name.

This method also works in the case that name is a String referencing a class. The method assumes that @extensions is an array where the registered object is the first element!

# File lib/webgen/extension_manager.rb, line 86
def extension(name)
  raise Webgen::Error.new("No extension called '#{name}' registered for the '#{self.class.name}' extension manager") unless registered?(name)
  name = name.to_sym
  ext = @extensions[name].object
  ext.kind_of?(String) ? @extensions[name].object = resolve_class(ext) : ext
end

Return a complete class name (including the hierarchy part) based on klass and the class name without the hierarchy part.

If the parameter do_autoload is true and the klass is defined under this class, it is autoloaded by turning the class name into a path name (See Webgen::Utils.snake_case).

# File lib/webgen/extension_manager.rb, line 72
def normalize_class_name(klass, do_autoload = true)
  klass = (klass.kind_of?(Class) || klass.include?('::') ? klass : "#{self.class.name}::#{klass}")
  klass_name = klass.to_s.split(/::/).last
  if do_autoload && klass.to_s.start_with?(self.class.name) && klass_name =~ /^[A-Z]/
    self.class.autoload(klass_name.to_sym, Webgen::Utils.snake_case(klass.to_s))
  end
  [klass, klass_name]
end

If class_or_name is a String, it is taken as the name of a class and is resolved. Else returns class_or_name.

# File lib/webgen/extension_manager.rb, line 102
def resolve_class(class_or_name)
  String === class_or_name ? Webgen::Utils.const_for_name(class_or_name) : class_or_name
end