# NAME

Config::Registry - Settings bundler.

# SYNOPSIS

## Create a Schema Class

```perl
package Org::Style;
use strictures 2;

use Types::Standard qw( Str );

use Moo;
use namespace::clean;

extends 'Config::Registry';

__PACKAGE__->schema({
    border_color => Str,
});

1;
```

## Create a Document Class

```perl
package MyApp::Style;
use strictures 2;

use Moo;
use namespace::clean;

extends 'Org::Style';

__PACKAGE__->document({
    border_color => '#333',
});

__PACKAGE__->publish();

1;
```

## Use a Document Class

```perl
use MyApp::Style;

my $style = MyApp::Style->fetch();

print '<table style="border-color:' . $style->border_color() . '">';
```

# SYNOPSIS

This module provides a framework for a pattern we've seen emerge in
ZipRecruiter code as we've been working to separate our monolithic
application into smaller and more manageable code bases.

The concept is pretty straightforward. A registry consists of a
schema class and one or more document classes. The schema is used to
validate the documents, and the documents are used to configure the
features of an application.

# SCHEMAS

```perl
__PACKAGE__->schema({
    border_color => Str,
});
```

The schema is a hash ref of attribute name and [Type::Tiny](https://metacpan.org/pod/Type%3A%3ATiny) pairs.
These pairs get turned into required [Moo](https://metacpan.org/pod/Moo) attributes when
["publish"](#publish) is called.

Top-level schema keys may have a hash ref, rather than a type, as
their value. This hash ref will be used directly to construct the
[Moo](https://metacpan.org/pod/Moo) attribute. The `required` option defaults on, and the `is`
option default to `ro`. You can of course override these in the
hash ref.

For example, the above code could be written as:

```perl
__PACKAGE__->schema({
    border_color => { isa => Str },
});
```

The attribute can be made optional by passing an options hash ref:

```perl
__PACKAGE__->schema({
    border_color => { isa => Str, required => 0 },
});
```

Non-top level keys can be made optional using [Type::Standard](https://metacpan.org/pod/Type%3A%3AStandard)'s
`Optional` type modifier:

```perl
__PACKAGE__->schema({
    border_colors => Dict[
        top    => Optional[ Str ],
        right  => Optional[ Str ],
        bottom => Optional[ Str ],
        left   => Optional[ Str ],
    ],
});
```

See ["Create a Schema Role"](#create-a-schema-role) for a complete example.

# DOCUMENTS

```perl
__PACKAGE__->document({
    border_color => '#333',
});
```

A document is a hash ref of attribute name value pairs.

A document is used as the default arguments when `new` is called
on the registry class.

See ["Create a Document Class"](#create-a-document-class) for a complete example.

# CLASS METHODS

## fetch

```perl
my $registry = $class->fetch();
```

Returns the singleton instance of the registry class.

# PACKAGE METHODS

## schema

```
__PACKAGE__->schema( \%schema );
```

Sets the schema hash ref. If a schema hash ref has already been
set then ["merge"](#merge) will be used to combine the passed in schema with
the existing schema.

See ["SCHEMAS"](#schemas) for more information about the schema hash ref
itself.

## document

```
__PACKAGE__->document( \%doc );
```

Sets the document hash ref. If a document hash ref has already been
set then ["merge"](#merge) will be used to combine the passed in document with
the existing document.

See ["DOCUMENTS"](#documents) for more information about the document hash ref
itself.

## publish

```
__PACKAGE__->publish();
```

Turns the ["schema"](#schema) hash ref into [Moo](https://metacpan.org/pod/Moo) attributes and enables the
registry class to be instantiated.

# SUPPORT

Please submit bugs and feature requests to the
Config-Registry GitHub issue tracker:

[https://github.com/bluefeet/Config-Registry/issues](https://github.com/bluefeet/Config-Registry/issues)

# ACKNOWLEDGEMENTS

Thanks to [ZipRecruiter](https://www.ziprecruiter.com/) for
encouraging their employees to contribute back to the open source
ecosystem. Without their dedication to quality software development
this distribution would not exist.

# AUTHOR

```
Aran Clary Deltac <bluefeet@gmail.com>
```

# COPYRIGHT AND LICENSE

Copyright (C) 2020 Aran Clary Deltac

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see [http://www.gnu.org/licenses/](http://www.gnu.org/licenses/).