NAME

       SReview::Config - Self-reproducing and self-documenting configuration file system

SYNOPSIS

         use SReview::Config;

         my $config = SReview::Config->new('/etc/sreview/config.pm');
         $config->define('name', 'The name of this element', 'default');
         ...
         print "You configured " . $config->get('name') . " as the name\n";
         print "Full configuration: \n" . $config->dump;

DESCRIPTION

       SReview::Config is a class to easily manage self-reproducing and self-documenting
       configuration. You create an SReview::Config object, populate it with possible
       configuration values, and then retrieve them.

METHODS

   SReview::Config->new('path/to/filename');
       Create a new SReview::Config object.

   $config->define(name, doc, default)
       Define a new configuration value. Not legal after "get" has already been called.

       Name should be the name of the configuration value. Apart from the fact that it should not
       have a sigil, it should be a valid name for a perl scalar variable.

   $config->define_deprecated(oldname, newname, conversion_sub)
       Define a name as a deprecated way of configuring things. When this value is set,
       SReview::Config will issue a warning that this option is now deprecated, and that the user
       should use some other option instead.

       The conversion subroutine is an optional argument that should mangle the value given to
       "oldname" into the value expected by "newname". If it returns nonzero, then
       SReview::Config will croak. It will receive a reference to the "config" object, the value
       that is trying to be set, and the name of the new parameter.

       The default conversion sub just sets the value of the newname configuration without any
       conversion.

   $config->define_computed('name')
       Defines a default value for a particular configuration parameter through a subroutine.

       If the subroutine returns "undef", that value will be ignored (and the normal logic for
       defining a default will be used).

       Should be used on a parameter that has already been defined through
         $config->define

   $config->get('name')
       Return the value of the given configuration item. Also finalizes the definitions of this
       configuration file; that is, once this method has been called, the "define" method above
       will croak.

       The returned value will either be the default value configured at "define" time, the value
       configured in the configuration file, or the value set (in JSON format) in the environment
       variable "SREVIEW_name ", where name is the upper-case version of the name of the
       configuration item.

   $config->set('name', value);
       Change the current value of the given configuration item.

       Note, this does not change the defaults, only the configured value.

   $config->describe('name');
       Return the documentation string for the given name

   $config->dump
       Return a string describing the whole configuration.

       Each configuration item will produced in one of the following two formats:

       •   For an item that only has a default set:

             # Documentation value given to define
             #$name = "default value";

       •   For an item that has a different value configured (either through the configuration
           file, or through "set"):

             # Documentation value given to define
             $name = "current value";

   $config->dump_item("item")
       Print a JSON value for the given configuration item. Prints the default item if this item
       hasn't been set a value.

   $config->is_default("item")
       Return a truthy value if the given configuration item is still at its default value.

BUGS

       It is currently not possible to load more than one configuration file in the same process
       space. This will be fixed at some point in the future.