Composition Pattern Without Inheritance

Code

<?php

/*
 * Copyright (c) 2026 Jeffery L. Paris <jparis@phpog.com>.
 * Free for personal and internal use. Paid project use requires visible credit
 * to Jeffery L. Paris. Corporate use requires a paid license fee unless a
 * separate written license states otherwise.
 */

/**
 * Composition Pattern Without Inheritance.
 *
 * Purpose:
 * Combines separate procedural data blocks into one composed result.
 *
 * @param array $ship Ship data.
 * @param array $crew Crew data.
 * @param array $mission Mission data.
 * @return array Composed mission asset.
 */
function ogSnippetCompositionPatternWithoutInheritance(array $ship, array $crew, array $mission): array {
	$composed = array(
		'ship' => array(),
		'crew' => array(),
		'mission' => array(),
		'ready' => false
	);

	$composed['ship'] = array(
		'name' => '',
		'class' => '',
		'ready' => false
	);

	if (isset($ship['name']) === true) {
		$composed['ship']['name'] = trim((string) $ship['name']);
	}

	if (isset($ship['class']) === true) {
		$composed['ship']['class'] = trim((string) $ship['class']);
	}

	if (isset($ship['ready']) === true) {
		$composed['ship']['ready'] = (bool) $ship['ready'];
	}

	$composed['crew'] = array(
		'captain' => '',
		'count' => 0
	);

	if (isset($crew['captain']) === true) {
		$composed['crew']['captain'] = trim((string) $crew['captain']);
	}

	if (isset($crew['count']) === true) {
		$crew_count = (int) $crew['count'];

		if ($crew_count >= 0) {
			$composed['crew']['count'] = $crew_count;
		}
	}

	$composed['mission'] = array(
		'name' => '',
		'priority' => 'normal'
	);

	if (isset($mission['name']) === true) {
		$composed['mission']['name'] = trim((string) $mission['name']);
	}

	if (isset($mission['priority']) === true) {
		$priority = strtolower(trim((string) $mission['priority']));

		if ($priority === 'low' || $priority === 'normal' || $priority === 'high') {
			$composed['mission']['priority'] = $priority;
		}
	}

	if ($composed['ship']['ready'] === true && $composed['crew']['count'] > 0 && $composed['mission']['name'] !== '') {
		$composed['ready'] = true;
	}

	return $composed;
}

$mission_asset = ogSnippetCompositionPatternWithoutInheritance(
	array('name' => 'Rocinante', 'class' => 'corvette', 'ready' => true),
	array('captain' => 'James Holden', 'count' => 4),
	array('name' => 'Ganymede recovery', 'priority' => 'high')
);

$asset_ready = 'no';

if ($mission_asset['ready'] === true) {
	$asset_ready = 'yes';
}

echo 'Composed asset ready: '.$asset_ready;