assets_task = Rake::Task.task_defined?('assets:precompile:primary') ? 'assets:precompile:primary' : 'assets:precompile'

Rake::Task.enhance do

require "tinymce/rails/asset_installer"

config   = Rails.application.config
target   = File.join(Rails.public_path, config.assets.prefix)
manifest = config.assets.manifest

assets = Pathname.new(File.expand_path(File.join(File.dirname(__FILE__),
  "../../app/assets/javascripts/tinymce/plugins/uploaddocument")))

TinyMCE::Rails::AssetInstaller.new(assets, target, manifest).install

end