Config::MVP::Reader - object to read config from storage into an assembler


version 2.200012


  use Config::MVP::Reader::YAML; # this doesn't really exist

  my $reader   = Config::MVP::Reader::YAML->new;

  my $sequence = $reader->read_config('/etc/foobar.yml');


A Config::MVP::Reader exists to read configuration data from storage (like a file) and convert that data into instructions to a Config::MVP::Assembler, which will in turn convert them into a Config::MVP::Sequence, the final product.



If true (which it is by default) then the current working directly will be locally added to @INC during config loading. This helps deal with changes made in Perl v5.26.1.



  my $sequence = $reader->read_config($location, \%arg);

This method is passed a location, which has no set meaning, but should be the mechanism by which the Reader is told how to locate configuration. It might be a file name, a hashref of parameters, a DBH, or anything else, depending on the needs of the specific Reader subclass.

It is also passed a hashref of arguments, of which there is only one valid argument:

 assembler - the Assembler object into which to read the config

If no assembler argument is passed, one will be constructed by calling the Reader's build_assembler method.

Subclasses should generally not override read_config, but should instead implement a read_into_assembler method, described below. If a subclass does override read_config it should take care to respect the add_cwd_to_lib attribute, above.


This method should not be called directly. It is called by read_config with the following parameters:

  my $sequence = $reader->read_into_assembler( $location, $assembler );

The method should read the configuration found at $location and use it to instruct the $assembler (a Config::MVP::Assembler) what configuration to perform.

The default implementation of this method will throw an exception complaining that it should have been implemented by a subclass.


If no Assembler is provided to read_config's assembler parameter, this method will be called on the Reader to construct one.

It must return a Config::MVP::Assembler object, and by default will return an entirely generic one.


Ricardo Signes <>


This software is copyright (c) 2021 by Ricardo Signes.

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