PHP Project Documentation: A Complete Guide from A to Z

Introduction: Why Documentation is Not a Luxury, but a Necessity

Every PHP developer has encountered a situation where someone else's (or even their own) code turns into a "dark forest" after a month. Lack of documentation is one of the main reasons why projects slow down and bugs multiply. Documenting code is not just a courtesy to colleagues, it is an investment in the project's future. In this article, we will break down how to properly write documentation for a PHP project using the PHPDoc standard, automation tools, and best practices.

1. PHPDoc Basics: Structure and Syntax

PHPDoc (or phpDocBlock) is a standard for commenting code in PHP that allows you not only to describe the purpose of a function or class but also to automatically generate documentation. Each documentation block begins with the characters /** and ends with */.

Basic DocBlock Structure

Let's look at a minimal block for a function:

<?php

/** * Calculates the sum of two numbers * * @param int $a The first addend * @param int $b The second addend * @return int The sum of the numbers */function sum(int $a, int $b): int {    return $a + $b;}

Key elements:

• Short description — the first line after the opening comment. It should be concise and clear.
• Long description (optional) — can follow after a blank line. Allows explaining complex algorithms.
• Tags — start with the @ symbol. Main ones: @param, @return, @throws.

Documenting Classes and Properties

Similar blocks are used for classes and properties:

<?php

/** * Class for working with users * * Provides methods for creating, updating, and deleting users. * All operations undergo validation and logging. */class UserManager {

    /**     * @var PDO|null Database connection object     */    private $db;

    /**     * @var LoggerInterface Logger instance     */    private $logger;

    /**     * Class constructor     *     * @param PDO $db PDO object for working with the database     * @param LoggerInterface $logger Logger object     */    public function __construct(PDO $db, LoggerInterface $logger) {        $this->db = $db;        $this->logger = $logger;    }}

2. Main PHPDoc Tags: Complete Reference

To create comprehensive documentation, you need to know the key tags. Here is a list of the most important ones:

Tags for Describing Types and Parameters

• @param — describes method/function parameters. Format: @param type $name Description.
• @return — describes the return value. Format: @return type Description.
• @var — describes the type of a class property.
• @throws — indicates which exceptions a method may throw.

Tags for Describing Structure and Metadata

• @see — link to another documentation element (class, method).
• @link — external link (URL).
• @deprecated — marks a deprecated element.
• @since — indicates the version from which the element is available.
• @author — code author.

Complex DocBlock Example

<?php

/** * Gets a list of user orders with pagination * * The method executes a database query using prepared statements. * Returns an array of Order objects. * * @param int $userId User ID * @param int $page Page number (starting from 1) * @param int $limit Number of records per page (max. 100) * @return array Array of Order objects\