class Nanoc::Int::PluginRegistry

The class responsible for keeping track of all loaded plugins, such as filters ({Nanoc::Filter}) and data sources ({Nanoc::DataSource}).

@api private

Public Class Methods

instance() click to toggle source

Returns the shared {PluginRegistry} instance, creating it if none exists yet.

@return [Nanoc::Int::PluginRegistry] The shared plugin registry

# File lib/nanoc/base/plugin_registry.rb, line 91
def self.instance
  @instance ||= new
end
new() click to toggle source

Creates a new plugin registry. This should usually not be necessary; it is recommended to use the shared instance (obtained from {Nanoc::Int::PluginRegistry.instance}).

# File lib/nanoc/base/plugin_registry.rb, line 98
def initialize
  @identifiers_to_classes = {}
  @classes_to_identifiers = {}
end

Public Instance Methods

all() click to toggle source

Returns a list of all plugins. The returned list of plugins is an array with array elements in the following format:

{ :class => ..., :superclass => ..., :identifiers => ... }

@return [Array<Hash>] A list of all plugins in the format described

# File lib/nanoc/base/plugin_registry.rb, line 168
def all
  plugins = []
  @identifiers_to_classes.each_pair do |superclass, submap|
    submap.each_pair do |identifier, klass|
      # Find existing plugin
      existing_plugin = plugins.find do |p|
        p[:class] == klass && p[:superclass] == superclass
      end

      if existing_plugin
        # Add identifier to existing plugin
        existing_plugin[:identifiers] << identifier
        existing_plugin[:identifiers] = existing_plugin[:identifiers].sort_by(&:to_s)
      else
        # Create new plugin
        plugins << {
          class: klass,
          superclass: superclass,
          identifiers: [identifier],
        }
      end
    end
  end

  plugins
end
find(klass, name) click to toggle source

Finds the plugin that is a subclass of the given class and has the given name.

@param [Class] klass The class of the plugin to return

@param [Symbol] name The name of the plugin to return

@return [Class, nil] The plugin with the given name

# File lib/nanoc/base/plugin_registry.rb, line 145
def find(klass, name)
  @identifiers_to_classes[klass] ||= {}
  resolve(@identifiers_to_classes[klass][name.to_sym], klass)
end
find_all(klass) click to toggle source

Returns all plugins of the given class.

@param [Class] klass The class of the plugin to return

@return [Enumerable<Class>] A collection of class plugins

# File lib/nanoc/base/plugin_registry.rb, line 155
def find_all(klass)
  @identifiers_to_classes[klass] ||= {}
  res = {}
  @identifiers_to_classes[klass].each_pair { |k, v| res[k] = resolve(v, k) }
  res
end
identifiers_of(superclass, klass) click to toggle source

@param [Class] superclass The superclass of the plugin. For example:

{Nanoc::Filter}.

@param [Class] klass The class to get the identifiers for.

@return [Array<Symbol>] An array of identifiers for the given class

# File lib/nanoc/base/plugin_registry.rb, line 133
def identifiers_of(superclass, klass)
  (@classes_to_identifiers[superclass] || {})[name_for_class(klass)] || []
end
register(superclass, class_or_name, *identifiers) click to toggle source

Registers the given class as a plugin.

@param [Class] superclass The superclass of the plugin. For example:

{Nanoc::Filter}.

@param [Class, String] class_or_name The class to register. This can be

a string, in which case it will be automatically converted to a proper
class at lookup. For example: `Nanoc::Filters::ERB`,
`"Nanoc::Filters::Haml"`.

@param [Symbol] identifiers One or more symbols identifying the class.

For example: `:haml`, :`erb`.

@return [void]

# File lib/nanoc/base/plugin_registry.rb, line 117
def register(superclass, class_or_name, *identifiers)
  @identifiers_to_classes[superclass] ||= {}
  @classes_to_identifiers[superclass] ||= {}

  identifiers.each do |identifier|
    @identifiers_to_classes[superclass][identifier.to_sym] = class_or_name
    (@classes_to_identifiers[superclass][name_for_class(class_or_name)] ||= []) << identifier.to_sym
  end
end

Protected Instance Methods

name_for_class(klass) click to toggle source
# File lib/nanoc/base/plugin_registry.rb, line 208
def name_for_class(klass)
  klass.to_s.sub(/^(::)?/, '::')
end
resolve(class_or_name, _klass) click to toggle source
# File lib/nanoc/base/plugin_registry.rb, line 197
def resolve(class_or_name, _klass)
  if class_or_name.is_a?(String)
    class_or_name.scan(/\w+/).reduce(Kernel) do |memo, part|
      memo.const_get(part)
    end
  else
    class_or_name
  end
end