lib/radiant/extension_loader.rb_

   1 # FIXME Rails dependencies / use gem
   2
   3 require 'radiant/extension'
   4 require 'method_observer'
   5
   6 module Radiant
   7   class ExtensionLoader
   8
   9     class DependenciesObserver < MethodObserver
  10       attr_accessor :config
  11
  12       def initialize(rails_config)
  13         @config = rails_config
  14       end
  15
  16       def before_clear(*args)
  17         ExtensionLoader.deactivate_extensions
  18       end
  19
  20       def after_clear(*args)
  21         ExtensionLoader.load_extensions
  22         ExtensionLoader.activate_extensions
  23       end
  24     end
  25
  26     include Simpleton
  27
  28     attr_accessor :initializer, :extensions
  29
  30     def initialize
  31       self.extensions = []
  32     end
  33
  34     def configuration
  35       initializer.configuration
  36     end
  37
  38     def extension_load_paths
  39       load_extension_roots.map { |extension| load_paths_for(extension) }.flatten.select { |d| File.directory?(d) }
  40     end
  41
  42     def plugin_paths
  43       load_extension_roots.map {|extension| "#{extension}/vendor/plugins" }.select {|d| File.directory?(d) }
  44     end
  45
  46     def add_extension_paths
  47       extension_load_paths.reverse_each do |path|
  48         configuration.load_paths.unshift path
  49         $LOAD_PATH.unshift path
  50       end
  51     end
  52
  53     def add_plugin_paths
  54       configuration.plugin_paths.concat plugin_paths
  55     end
  56
  57     def controller_paths
  58       extensions.map { |extension| "#{extension.root}/app/controllers" }.select { |d| File.directory?(d) }
  59     end
  60
  61     def add_controller_paths
  62       configuration.controller_paths.concat(controller_paths)
  63     end
  64
  65     def view_paths
  66       extensions.map { |extension| "#{extension.root}/app/views" }.select { |d| File.directory?(d) }
  67     end
  68
  69     # Load the extensions
  70     def load_extensions
  71       @observer ||= DependenciesObserver.new(configuration).observe(::Dependencies)
  72       self.extensions = load_extension_roots.map do |root|
  73         begin
  74           extension_file = "#{File.basename(root).sub(/^\d+_/,'')}_extension"
  75           extension = extension_file.camelize.constantize
  76           extension.unloadable
  77           extension.root = root
  78           extension
  79         rescue LoadError, NameError => e
  80           $stderr.puts "Could not load extension from file: #{extension_file}.\n#{e.inspect}"
  81           nil
  82         end
  83       end.compact
  84     end
  85
  86     def deactivate_extensions
  87       extensions.each &:deactivate
  88     end
  89
  90     def activate_extensions
  91       initializer.initialize_default_admin_tabs
  92       # Reset the view paths after
  93       initializer.initialize_framework_views
  94       extensions.each &:activate
  95     end
  96     alias :reactivate :activate_extensions
  97
  98     private
  99
 100       def load_paths_for(dir)
 101         if File.directory?(dir)
 102           %w(lib app/models app/controllers app/helpers test/helpers).collect do |p|
 103             path = "#{dir}/#{p}"
 104             path if File.directory?(path)
 105           end.compact << dir
 106         else
 107           []
 108         end
 109       end
 110
 111       def load_extension_roots
 112         @load_extension_roots ||= unless configuration.extensions.empty?
 113           select_extension_roots
 114         else
 115           []
 116         end
 117       end
 118
 119       def select_extension_roots
 120         all_roots = all_extension_roots.dup
 121
 122         roots = configuration.extensions.map do |ext_name|
 123           if :all === ext_name
 124             :all
 125           else
 126             ext_path = all_roots.detect do |maybe_path|
 127               File.basename(maybe_path).sub(/^\d+_/, '') == ext_name.to_s
 128             end
 129             raise LoadError, "Cannot find the extension '#{ext_name}'!" if ext_path.nil?
 130             all_roots.delete(ext_path)
 131           end
 132         end
 133
 134         if placeholder = roots.index(:all)
 135           # replace the :all symbol with any remaining paths
 136           roots[placeholder, 1] = all_roots
 137         end
 138         roots
 139       end
 140
 141       def all_extension_roots
 142         @all_extension_roots ||= configuration.extension_paths.map do |path|
 143           Dir["#{path}/*"].map {|f| File.expand_path(f) if File.directory?(f) }.compact.sort
 144         end.flatten
 145       end
 146   end
 147 end