Catalyst::Plugin::ConfigLoader(3) Load config files of various types

SYNOPSIS


package MyApp;
# ConfigLoader should be first in your list so
# other plugins can get the config information
use Catalyst qw( ConfigLoader ... );
# by default myapp.* will be loaded
# you can specify a file if you'd like
__PACKAGE__->config( 'Plugin::ConfigLoader' => { file => 'config.yaml' } );
In the file, assuming it's in YAML format:
foo: bar
Accessible through the context object, or the class itself
$c->config->{foo} # bar
MyApp->config->{foo} # bar

DESCRIPTION

This module will attempt to load find and load a configuration file of various types. Currently it supports YAML, JSON, XML, INI and Perl formats. Special configuration for a particular driver format can be stored in "MyApp->config->{ 'Plugin::ConfigLoader' }->{ driver }". For example, to pass arguments to Config::General, use the following: 

    __PACKAGE__->config( 'Plugin::ConfigLoader' => {
        driver => {
            'General' => { -LowerCaseNames => 1 }
        }
    } );

See Config::Any's "driver_args" parameter for more information.

To support the distinction between development and production environments, this module will also attemp to load a local config (e.g. myapp_local.yaml) which will override any duplicate settings. See get_config_local_suffix for details on how this is configured.

METHODS

setup( )

This method is automatically called by Catalyst's setup routine. It will attempt to use each plugin and, once a file has been successfully loaded, set the "config()" section.

load_config

This method handles loading the configuration data into the Catalyst context object. It does not return a value.

find_files

This method determines the potential file paths to be used for config loading. It returns an array of paths (up to the filename less the extension) to pass to Config::Any for loading.

get_config_path

This method determines the path, filename prefix and file extension to be used for config loading. It returns the path (up to the filename less the extension) to check and the specific extension to use (if it was specified).

The order of preference is specified as:

  • $ENV{ MYAPP_CONFIG }
  • $ENV{ CATALYST_CONFIG }
  • "$c->config->{ 'Plugin::ConfigLoader' }->{ file }"
  • "$c->path_to( $application_prefix )"

If either of the first two user-specified options are directories, the application prefix will be added on to the end of the path.

get_config_local_suffix

Determines the suffix of files used to override the main config. By default this value is "local", which will load "myapp_local.conf". The suffix can be specified in the following order of preference:
  • $ENV{ MYAPP_CONFIG_LOCAL_SUFFIX }
  • $ENV{ CATALYST_CONFIG_LOCAL_SUFFIX }
  • "$c->config->{ 'Plugin::ConfigLoader' }->{ config_local_suffix }"

The first one of these values found replaces the default of "local" in the name of the local config file to be loaded.

For example, if $ENV{ MYAPP_CONFIG_LOCAL_SUFFIX } is set to "testing", ConfigLoader will try and load "myapp_testing.conf" instead of "myapp_local.conf".

finalize_config

This method is called after the config file is loaded. It can be used to implement tuning of config values that can only be done at runtime. If you need to do this to properly configure any plugins, it's important to load ConfigLoader before them. ConfigLoader provides a default finalize_config method which walks through the loaded config hash and calls the "config_substitutions" sub on any string.

config_substitutions( $value )

This method substitutes macros found with calls to a function. There are a number of default macros:
  • "__HOME__" - replaced with "$c->path_to('')"
  • "__ENV(foo)__" - replaced with the value of $ENV{foo}
  • "__path_to(foo/bar)__" - replaced with "$c->path_to('foo/bar')"
  • "__literal(__FOO__)__" - leaves __FOO__ alone (allows you to use "__DATA__" as a config value, for example)

The parameter list is split on comma (","). You can override this method to do your own string munging, or you can define your own macros in "MyApp->config->{ 'Plugin::ConfigLoader' }->{ substitutions }". Example: 

    MyApp->config->{ 'Plugin::ConfigLoader' }->{ substitutions } = {
        baz => sub { my $c = shift; qux( @_ ); }
    }

The above will respond to "__baz(x,y)__" in config strings.

AUTHOR

Brian Cassidy <[email protected]>

CONTRIBUTORS

The following people have generously donated their time to the development of this module:

Work to this module has been generously sponsored by:

COPYRIGHT AND LICENSE

Copyright 2006-2010 by Brian Cassidy

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

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