Types

The types package is an extension to the alleyinteractive/wp-type-extensions package.

The feature pattern is used by Mantle and throughout Alley projects to define features on a project. It provides a consistent way to register and manage features that promotes modularity and reusability.

Lets look at an example of a feature:

use Alley\WP\Types\Feature;

class My_Custom_Type_Feature extends Feature {
  public function boot(): void {
    // Register custom types here.
  }
}

The My_Custom_Type_Feature class extends the Feature interface, which requires the implementation of a boot() method. This method is called when the feature is initialized.

Features can be booted in a group using the Group class:

use Alley\WP\Features\Group;

$group = new Group(
  new My_Custom_Type_Feature(),
);

$group->boot();

For more information about the wp-type-extensions project, see the project's README.

Hookable Feature

The Hookable_Feature class implements the Feature interface and uses the Hookable trait to provide a convenient way to register WordPress hooks within a feature.

use Mantle\Support\Attributes\Action;
use Mantle\Types\Hookable_Feature;

class Example_Feature extends Hookable_Feature {
  #[Action('init')]
  public function register_custom_type(): void {
    // Register custom types here.
  }
}

You can then use the feature normally within a feature group.

use Alley\WP\Features\Group;

$group = new Group(
  new Example_Feature(),
);

$group->boot();

The Hookable trait will add the register_custom_type method as a callback for the init action when the feature is booted.

Validator Group

The Validator_Group class allows you boot features in a group with run-time validation. For example, you can add all the possible features to be booted to a validator group, and then only the features that pass validation will be booted.

Validation is done using attributes that implement the Mantle\Types\Validator interface. Features that include the attribute will only be booted if the attribute's validate method returns true. Features that do not include any validator attributes will always be booted.

Let's look at an example custom validator attribute:

use Alley\WP\Types\Feature;

#[\Attribute]
class Example_Validator implements \Mantle\Types\Validator {
  public function validate(): bool {
    return wp_rand(0, 1) === 1;
  }
}

You can then use the validator attribute on a feature:

use Mantle\Support\Attributes\Action;
use Mantle\Types\Hookable_Feature;

#[Example_Validator]
class Example_Feature extends Hookable_Feature {
  #[Action('init')]
  public function register_custom_type(): void {
    // Register custom types here.
  }
}

To put it all together, the validator group will be used to selectively boot the features:

use Mantle\Types\Validator_Group;

$group = new Validator_Group(
  new Example_Feature(),
  new \Alley\WP\Features\Quick_Feature( function (): void {
    // This feature will always be booted because it has no validators.
  } ),
);

$group->boot();

The Example_Feature will only be booted if the Example_Validator returns true.

Validator Attribute

A validator attribute is a PHP attribute that implements the Mantle\Types\Validator interface. The attribute's validate method is called when the class is being initialized to determine if the feature should be booted.

Here's an example of a custom validator attribute:

class Example_Validator implements \Mantle\Types\Validator {
  public function validate(): bool {
    // Return true to boot the feature, false to skip it.
  }
}

Available Validators

The following validator attributes are available:

CLI

The Mantle\Types\Attributes\CLI validator attribute will only allow the feature to be booted if the current request is from the command line interface (CLI).

use Alley\WP\Types\Feature;
use Mantle\Types\Attributes\CLI;

#[CLI]
class CLI_Only_Feature extends Feature {
  public function boot(): void {
    // This feature will only be booted when running in the CLI.
  }
}

Environment

The Mantle\Types\Attributes\Environment validator attribute will only allow the feature to be booted if the current environment matches one of the specified environments.

One or more environment names can be passed to the attribute.

use Alley\WP\Types\Feature;
use Mantle\Types\Attributes\Environment;

#[Environment('production', 'staging')]
class Production_Staging_Feature extends Feature {
  public function boot(): void {
    // This feature will only be booted in the 'production' or 'staging' environments.
  }
}