Module: FancyRequire

Defined in:
lib/fancy_require.rb

Overview

FancyRequire allows you to push an object onto $LOAD_PATH that will find files to load. You can use this to implement fancier require behavior without overriding Kernel#require.

The lookup object you push onto $LOAD_PATH must respond to #path_for. The feature being required (file name) will be passed in by FancyRequire.

The lookup object must return the path to the feature, true, false or nil.

If nil is returned FancyRequire will continue to search down the load path.

If true or false are returned the lookup object handled loading the file and recording it in $LOADED_FEATURES. The boolean will be returned as plain require.

Example

The easiest way to use FancyRequire is to require it everywhere (which includes it in Object):

require 'fancy_require/everywhere'

Then create a LookUp object and add it to the load path. This LookUp object looks in a ‘lookup’ directory under the current path.

class LookUp
  def initialize directory
    @directory = directory
  end

  def path_for feature
    Dir["#{Dir.pwd}/#{directory}/lookup/#{feature}{#{FancyRequire::SUFFIX_GLOB}}"].first
  end
end

$LOAD_PATH.unshift LookUp.new 'test'

Then require works like normal.

require 'toad' # looks for ./test/lookup/toad.rb

Constant Summary collapse

VERSION =

The version of FancyRequire you’re using… not that I know why you’re using FancyRequire

'1.0'
SUFFIX_GLOB =

Dir#glob list of ruby file suffixes

Gem.suffixes.join ','
SUFFIX_RE =

Regexp list of ruby file suffixes

Regexp.union Gem.suffixes

Instance Method Summary collapse

Instance Method Details

#loaded?(feature) ⇒ Boolean

Is feature already in $LOADED_FEATURES?

NOTE: this method is not 100% compatible with ruby

Returns:

  • (Boolean) 


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# File 'lib/fancy_require.rb', line 111

def loaded? feature
  $LOADED_FEATURES.any? do |path|
    path =~ /^#{feature}#{SUFFIX_RE}$/
  end
end

#require(feature) ⇒ Object

Replacement for Kernel#require

NOTE: this method is not 100% compatible with ruby

Raises:

  • (LoadError) 


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# File 'lib/fancy_require.rb', line 68

def require feature
  return false if loaded? feature # 1.8

  path = nil

  $LOAD_PATH.each do |obj|
    path = case obj
           when String then
             Dir["#{obj}/#{feature}{#{FancyRequire::SUFFIX_GLOB}}"].find do |item|
               File.file? item
             end
           else
             obj.path_for feature
           end

    case path
    when true, false
      return path
    else
      break if path
    end
  end

  raise LoadError, "no such file to load -- #{feature}" unless path

  return false if loaded? path # 1.9

  load path

  if RUBY_VERSION > '1.9' then
    $LOADED_FEATURES << path
  else
    $LOADED_FEATURES << File.basename(path)
  end

  true
end