Module: CodeRay::PluginHost

Included in:
Encoders, Scanners, Styles
Defined in:
lib/coderay/helpers/plugin.rb

Overview

PluginHost

A simple subclass/subfolder plugin system.

Example:

class Generators
  extend PluginHost
  plugin_path 'app/generators'
end

class Generator
  extend Plugin
  PLUGIN_HOST = Generators
end

class FancyGenerator < Generator
  register_for :fancy
end

Generators[:fancy]  #-> FancyGenerator
# or
CodeRay.require_plugin 'Generators/fancy'
# or
Generators::Fancy

Constant Summary collapse

PluginNotFound =

Raised if Encoders::[] fails because:

  • a file could not be found

  • the requested Plugin is not registered

Class.new LoadError
HostNotFound = 
Class.new LoadError
PLUGIN_HOSTS = 
[]
PLUGIN_HOSTS_BY_ID =

dummy hash

{}

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.extended(mod) ⇒ Object

Adds the module/class to the PLUGIN_HOSTS list.



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# File 'lib/coderay/helpers/plugin.rb', line 72

def extended mod
  PLUGIN_HOSTS << mod
end

Instance Method Details

#[](id, *args, &blk) ⇒ Object Also known as: load

Returns the Plugin for id.

Example:

yaml_plugin = MyPluginHost[:yaml]



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# File 'lib/coderay/helpers/plugin.rb', line 49

def [] id, *args, &blk
  plugin = validate_id(id)
  begin
    plugin = plugin_hash.[] plugin, *args, &blk
  end while plugin.is_a? Symbol
  plugin
end

#all_plugins ⇒ Object

Returns an array of all Plugins.

Note: This loads all plugins using load_all.



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# File 'lib/coderay/helpers/plugin.rb', line 151

def all_plugins
  load_all
  plugin_hash.values.grep(Class)
end

#const_missing(const) ⇒ Object

Tries to load the missing plugin by translating const to the underscore form (eg. LinesOfCode becomes lines_of_code).



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# File 'lib/coderay/helpers/plugin.rb', line 61

def const_missing const
  id = const.to_s.
    gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').
    gsub(/([a-z\d])([A-Z])/,'\1_\2').
    downcase
  load id
end

#default(id = nil) ⇒ Object

Define the default plugin to use when no plugin is found for a given id, or return the default plugin.

See also map.

class MyColorHost < PluginHost
  map :navy => :dark_blue
  default :gray
end

MyColorHost.default  # loads and returns the Gray plugin



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# File 'lib/coderay/helpers/plugin.rb', line 114

def default id = nil
  if id
    id = validate_id id
    raise "The default plugin can't be named \"default\"." if id == :default
    plugin_hash[:default] = id
  else
    load :default
  end
end

#list ⇒ Object

Returns an array of all .rb files in the plugin path.

The extension .rb is not included.



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# File 'lib/coderay/helpers/plugin.rb', line 140

def list
  Dir[path_to('*')].select do |file|
    File.basename(file)[/^(?!_)\w+\.rb$/]
  end.map do |file|
    File.basename(file, '.rb').to_sym
  end
end

#load_all ⇒ Object

Loads all plugins using list and load.



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# File 'lib/coderay/helpers/plugin.rb', line 39

def load_all
  for plugin in list
    load plugin
  end
end

#load_plugin_map ⇒ Object

Loads the map file (see map).

This is done automatically when plugin_path is called.



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# File 'lib/coderay/helpers/plugin.rb', line 159

def load_plugin_map
  mapfile = path_to '_map'
  @plugin_map_loaded = true
  if File.exist? mapfile
    require mapfile
    true
  else
    false
  end
end

#map(hash) ⇒ Object

Map a plugin_id to another.

Usage: Put this in a file plugin_path/_map.rb.

class MyColorHost < PluginHost
  map :navy => :dark_blue,
    :maroon => :brown,
    :luna => :moon
end



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# File 'lib/coderay/helpers/plugin.rb', line 95

def map hash
  for from, to in hash
    from = validate_id from
    to = validate_id to
    plugin_hash[from] = to unless plugin_hash.has_key? from
  end
end

#plugin_hash ⇒ Object

A Hash of plugion_id => Plugin pairs.



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# File 'lib/coderay/helpers/plugin.rb', line 133

def plugin_hash
  @plugin_hash ||= make_plugin_hash
end

#plugin_path(*args) ⇒ Object

The path where the plugins can be found.



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# File 'lib/coderay/helpers/plugin.rb', line 79

def plugin_path *args
  unless args.empty?
    @plugin_path = File.expand_path File.join(*args)
  end
  @plugin_path ||= ''
end

#register(plugin, id) ⇒ Object

Every plugin must register itself for id by calling register_for, which calls this method.

See Plugin#register_for.



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# File 'lib/coderay/helpers/plugin.rb', line 128

def register plugin, id
  plugin_hash[validate_id(id)] = plugin
end