1 module Puppet::Parser::Functions
2 newfunction(:pick_default, :type => :rvalue, :doc => <<-EOS
4 This function is similar to a coalesce function in SQL in that it will return
5 the first value in a list of values that is not undefined or an empty string
6 (two things in Puppet that will return a boolean false value). If no value is
7 found, it will return the last argument.
9 Typically, this function is used to check for a value in the Puppet
10 Dashboard/Enterprise Console, and failover to a default value like the
13 $real_jenkins_version = pick_default($::jenkins_version, '1.449')
15 The value of $real_jenkins_version will first look for a top-scope variable
16 called 'jenkins_version' (note that parameters set in the Puppet Dashboard/
17 Enterprise Console are brought into Puppet as top-scope variables), and,
18 failing that, will use a default value of 1.449.
20 Note that, contrary to the pick() function, the pick_default does not fail if
21 all arguments are empty. This allows pick_default to use an empty value as
26 fail "Must receive at least one argument." if args.empty?
28 args = args[0..-2].compact
30 args.delete(:undefined)