NAME

Config::Station - Load configs from files and the environment

VERSION

version 0.002001

SYNOPSIS

Define your config class:

 package MyApp::Config;

 use Moo;

 has www_port => (
   is => 'ro',
   required => 1,
 );

 has static_path => (
   is => 'ro',
   default => 'view/static',
 );

 1;

And elsewhere you load it up:

 my $station = Config::Station->new(
   config_class => 'MyApp::Config',
   env_key      => 'MYAPP',
   location     => '.config.json',
 );

 my $config = $station->load;

DESCRIPTION

This config loader offers a couple of major features that make it compelling for the user:

1. Object based configuration

This is a huge deal. This means that you can trivially set defaults, add validation, and an other number of cool things. On top of that this means that unless you do something silly, your configuration has clearly defined fields, instead of being a shapeless hash.

2. Environment based overriding

Presumably many users of this module will be loading their config from a file. That's fine and normal, but baked into the module is and an environment based config solution. This allows the user to change, for example, a port, by just running the application as follows:

 MYAPP_WWW_PORT=8080 perl bin/myapp.pl

ATTRIBUTES

 my $station = Config::Station->new( env_key => 'MYAPP' )

env_key

The env_key is a required attribute which affects everything about this module.

env_key affects two classes of values:

Meta Configuration

These values use the env_key as a suffix, and are documented further down.

Normal Configuration

These values use the env_key as a prefix for env vars that override configuration keys. To be clear, if you specify an env_key of FOO, an env var of FOO_BAR=BAZ will pass bar => 'BAZ' to the constructor of "config_class".

config_class

The config_class is a required attribute which determines the class that will be used when loading the configuration. The config class absolutely must have a new method which takes a hash. What it returns is up to you.

If you care to, you can define a serialize method on the object which supports the "store" method, but I suspect that is likely not a typical use case.

debug

Debugging is critical feature of this module. If you set this attribute directly, or indirectly by setting the env var 'DEBUG_' . $env_key, you will get some handy debugging output warned. It looks like this:

 CONFIGSTATION FROM FILE:
   name: herp
 CONFIGSTATION FROM ENV:
   id: 1
   name: wins

If the file can't be loaded or parsed, for some reason, instead of listing key-value pairs, the output for the file will be:

 CONFIGSTATION FROM FILE: $exception

Note that failure to load or deserialize the file is not considered an error. If you want to enforce that data is set do that by making your object constructor more strict.

location

The location can be set directly, or indirectly by setting the env var 'FILE_' . $env_key. As noted above, it is neither required to be set or parseable at all.

decode_via

 my $station = Config::Station->new( ..., decode_via => sub { \&YAML::Load );

A code reference which can inflate a string into a hash reference. Default uses JSON.

encode_via

 my $station = Config::Station->new( ..., encode_via => sub { \&YAML::Dump );

A code reference which can deflate a hash reference into a string. Default uses JSON.

AUTHOR

Arthur Axel "fREW" Schmidt <frioux+cpan@gmail.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2015 by Arthur Axel "fREW" Schmidt.

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

cpanm Config::Station

perl -MCPAN -e shell
install Config::Station