/ 
Object-Configure-0.14
River stage two • 5 direct dependents • 13 total dependents
/ Object::Configure

NAME

Object::Configure - Runtime Configuration for an Object

VERSION

0.14

SYNOPSIS

The Object::Configure module is a lightweight utility designed to inject runtime parameters into other classes, primarily by layering configuration and logging support, when instatiating objects.

Log::Abstraction and Config::Abstraction are modules developed to solve a specific need: runtime configurability without needing to rewrite or hardcode behaviours. The goal is to allow individual modules to enable or disable features on the fly, and to do it using whatever configuration system the user prefers.

Although the initial aim was general configurability, the primary use case that's emerged has been fine-grained logging control, more flexible and easier to manage than what you'd typically do with Log::Log4perl. For example, you might want one module to log verbosely while another stays quiet, and be able to toggle that dynamically - without making invasive changes to each module.

To tie it all together, there is Object::Configure. It sits on Log::Abstraction and Config::Abstraction, and with just a couple of extra lines in a class constructor, you can hook in this behaviour seamlessly. The intent is to keep things modular and reusable, especially across larger systems or in situations where you want user-selectable behaviour.

Add this to your constructor:

package My::Module;

use Object::Configure;
use Params::Get;

sub new {
     my $class = shift;
     my $params = Object::Configure::configure($class, @_ ? \@_ : undef);	# Reads in the runtime configuration settings

     return bless $params, $class;
 }

Throughout your class, add code such as:

sub method
{
    my $self = shift;

    $self->{'logger'}->trace(ref($self), ': ', __LINE__, ' entering method');
}

CHANGING BEHAVIOUR AT RUN TIME

USING A CONFIGURATION FILE

To control behavior at runtime, Object::Configure supports loading settings from a configuration file via Config::Abstraction.

A minimal example of a config file (~/.conf/local.conf) might look like:

[My__Module]
logger.file = /var/log/mymodule.log

The configure() function will read this file, overlay it onto your default parameters, and initialize the logger accordingly.

If the file is not readable and no config_dirs are provided, the module will throw an error.

This mechanism allows dynamic tuning of logging behavior (or other parameters you expose) without modifying code.

More details to be written.

USING ENVIRONMENT VARIABLES

Object::Configure also supports runtime configuration via environment variables, without requiring a configuration file.

Environment variables are read automatically when you use the configure() function, thanks to its integration with Config::Abstraction. These variables should be prefixed with your class name, followed by a double colon.

For example, to enable syslog logging for your My::Module class, you could set:

export My__Module__logger__file=/var/log/mymodule.log

This would be equivalent to passing the following in your constructor:

My::Module->new(logger => Log::Abstraction->new({ file => '/var/log/mymodule.log' });

All environment variables are read and merged into the default parameters under the section named after your class. This allows centralized and temporary control of settings (e.g., for production diagnostics or ad hoc testing) without modifying code or files.

Note that environment variable settings take effect regardless of whether a configuration file is used, and are applied during the call to configure().

More details to be written.

SUBROUTINES/METHODS

configure

Configure your class at runtime.

Takes arguments:

  • class

  • params

    A hashref containing default parameters to be used in the constructor.

  • carp_on_warn

    If set to 1, call Carp:carp on warn(). This value is also read from the configuration file, which will take precendence.

Returns a hash ref conntaining the new values for the constructor. The hash ref will have at least one element - the logger.

Now you can set up a configuration file and environment variables to configure your object.

instantiate($class,...)

Create and configure an object of the given class. This is a quick and dirty way of making third-party classes configurable at runtime.

SEE ALSO

SUPPORT

This module is provided as-is without any warranty.

Please report any bugs or feature requests to bug-object-configure at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Object-Configure. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

You can find documentation for this module with the perldoc command.

perldoc Object::Configure

LICENSE AND COPYRIGHT

Copyright 2025 Nigel Horne.

Usage is subject to licence terms.

The licence terms of this software are as follows:

  • Personal single user, single computer use: GPL2

  • All other users (including Commercial, Charity, Educational, Government) must apply in writing for a licence for use from Nigel Horne at the above e-mail.