Config::Structured - Provides generalized and structured configuration value access


version 2.002


Basic usage:

  use Config::Structured;

  my $conf = Config::Structured->new(
    structure    => { ... },
    config       => { ... }

  say $conf->some->nested->value();

Hooks exammple showing how to ensure config directories exist prior to first use:

  my $conf = Config::Structured->new(
    hooks => {
      '/paths/*' => {
        on_load => sub($node,$value) {


  L<Config::Structured> provides a structured method of accessing configuration values

  This is predicated on the use of a configuration C<structure> (required), This structure
  provides a hierarchical structure of configuration branches and leaves. Each branch becomes
  a L<Config::Structured> method which returns a new L<Config::Structured> instance rooted at
  that node, while each leaf becomes a method which returns the configuration value.

  The configuration value is normally provided in the C<config> hash. However, a C<config> node
  for a non-Hash value can be a hash containing the "source" and "ref" keys. This permits sourcing
  the config value from a file (when source="file") whose filesystem location is given in the "ref"
  value, or an environment variable (when source="env") whose name is given in the "ref" value.

  I<Structure Leaf Nodes> are required to include an "isa" key, whose value is a type 
  (see L<Moose::Util::TypeConstraints>). If typechecking is not required, use isa => 'Any'.
  There are a few other keys that L<Config::Structured> respects in a leaf node:


  =item C<default>

  This key's value is the default configuration value if a data source or value is not provided by
  the configuation.

  =item C<description>

  =item C<notes>

  A human-readable description and implementation notes, respectively, of the configuration node. 
  L<Config::Structured> does not do anything with these values at present, but they provides inline 
  documentation of configuration directivess within the structure (particularly useful in the common 
  case where the structure is read from a file)


  Besides C<structure> and C<config>, L<Config::Structured> also accepts a C<hooks> argument at 
  initialization time. This argument must be a HashRef whose keys are patterns matching config
  node paths, and whose values are HashRefs containing C<on_load> and/or C<on_access> keys. These
  in turn point to CodeRefs which are run when the config value is initially loaded, or every time
  it is accessed, respectively.



Class method.

Returns a registered Config::Structured instance. If $name is not provided, returns the default instance. Instances can be registered with __register_default or __register_as. This mechanism is used to provide global access to a configuration, even from code contexts that otherwise cannot share data.


Call on a Config::Structured instance to set the instance as the default.


Call on a Config::Structured instance to register the instance as the provided name.


Mark Tyrrell <>


This software is copyright (c) 2019 by Concert Pharmaceuticals, Inc.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.