puppetlabs-stdlib/lib/puppet/parser/functions/pick.rb
Gary Larizza ba6dd13990 Add the pick() function
This function is similar to a coalesce function in SQL in that it will
return
the first value in a list of values that is not undefined or an empty
string
(two things in Puppet that will return a boolean false value).
Typically,
this function is used to check for a value in the Puppet
Dashboard/Enterprise
Console, and failover to a default value like the following:

  $real_jenkins_version = pick($::jenkins_version, '1.449')

The value of $real_jenkins_version will first look for a top-scope
variable
called 'jenkins_version' (note that parameters set in the Puppet
Dashboard/
Enterprise Console are brought into Puppet as top-scope variables), and,
failing that, will use a default value of 1.449.
2012-11-15 08:52:19 -05:00

29 lines
1,017 B
Ruby

module Puppet::Parser::Functions
newfunction(:pick, :type => :rvalue, :doc => <<-EOS
This function is similar to a coalesce function in SQL in that it will return
the first value in a list of values that is not undefined or an empty string
(two things in Puppet that will return a boolean false value). Typically,
this function is used to check for a value in the Puppet Dashboard/Enterprise
Console, and failover to a default value like the following:
$real_jenkins_version = pick($::jenkins_version, '1.449')
The value of $real_jenkins_version will first look for a top-scope variable
called 'jenkins_version' (note that parameters set in the Puppet Dashboard/
Enterprise Console are brought into Puppet as top-scope variables), and,
failing that, will use a default value of 1.449.
EOS
) do |args|
args = args.compact
args.delete(:undef)
args.delete(:undefined)
args.delete("")
if args[0].to_s.empty? then
fail "Must provide non empty value."
else
return args[0]
end
end
end