module Jekyll::External

Public Class Methods

blessed_gems() click to toggle source

Gems that, if installed, should be loaded. Usually contain subcommands.

# File lib/jekyll/external.rb, line 8
def blessed_gems
  %w(
    jekyll-docs
    jekyll-import
  )
end
require_if_present(names, &block) click to toggle source

Require a gem or file if it's present, otherwise silently fail.

names - a string gem name or array of gem names

# File lib/jekyll/external.rb, line 20
def require_if_present(names, &block)
  Array(names).each do |name|
    begin
      require name
    rescue LoadError
      Jekyll.logger.debug "Couldn't load #{name}. Skipping."
      block.call(name) if block
      false
    end
  end
end
require_with_graceful_fail(names) click to toggle source

Require a gem or gems. If it's not present, show a very nice error message that explains everything and is much more helpful than the normal LoadError.

names - a string gem name or array of gem names

# File lib/jekyll/external.rb, line 39
      def require_with_graceful_fail(names)
        Array(names).each do |name|
          begin
            Jekyll.logger.debug "Requiring:", "#{name}"
            require name
          rescue LoadError => e
            Jekyll.logger.error "Dependency Error:", <<-MSG
Yikes! It looks like you don't have #{name} or one of its dependencies installed.
In order to use Jekyll as currently configured, you'll need to install this gem.

The full error message from Ruby is: '#{e.message}'

If you run into trouble, you can find helpful resources at http://jekyllrb.com/help/!
            MSG
            raise Jekyll::Errors::MissingDependencyException.new(name)
          end
        end
      end