(#8010) Add getvar() rvalue function

This isn't directly related to #8010, but rather indirectly fills the
need to allow the end user to configure where data values are looked up.

This allows the namespace to be passed as a class parameter.  A module
may then quickly and easily look up data from the user-defined
namespace.

1 files changed, 23 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/getvar.rb b/lib/puppet/parser/functions/getvar.rb
new file mode 100644
index 0000000..ffd774d
--- /dev/null
+++ b/lib/puppet/parser/functions/getvar.rb
@@ -0,0 +1,23 @@
+module Puppet::Parser::Functions
+
+  newfunction(:getvar, :type => :rvalue, :doc => <<-'ENDHEREDOC') do |args|
+    Lookup a variable in a remote namespace.
+
+    For example:
+
+      $foo = getvar('site::data::foo')
+
+    This is useful if the namespace itself is stored in a string:
+
+      $bar = getvar("${datalocation}::bar")
+    ENDHEREDOC
+
+    unless args.length == 1
+      raise Puppet::ParseError, ("getvar(): wrong number of arguments (#{args.length}; must be 1)")
+    end
+
+    self.lookupvar("#{args[0]}")
+
+  end
+
+end