default_content(1.8.7).rb

Puppet::Parser::Functions.newfunction(:default_content,
                                      :type => :rvalue,
                                      :doc => <<-'ENDOFDOC'
Takes an optional content and an optional template name and returns the
contents of a file.

Examples:

    $config_file_content = default_content($file_content, $template_location)
    file { '/tmp/x':
      ensure  => 'file',
      content => $config_file_content,
    }
ENDOFDOC
) do |args|
  content = args[0]
  template_name = args[1]

  emptyish = lambda { |x| x.nil? || x.empty? || x == :undef }

  return content unless emptyish.call(content)
  return call_function('template', template_name) unless emptyish.call(template_name)

  return :undef