A generic tree manipulation class that can build, sort, and format hierarchical data structures (e.g., menus, categories, permissions). It accepts nested arrays with parent IDs and returns ordered trees with children arrays. The class is dependency-free (no ThinkPHP imports) and can be extracted into any PHP project for handling parent-child relationships.

A comprehensive input sanitization and XSS filtering library inspired by CodeIgniter's Security class. It performs multi-step cleansing including URL/entity decoding, naughty HTML removal, image upload validation, and filename sanitization. While the code is monolithic and uses the deprecated mcrypt extension for random strings, the core XSS cleaning logic is self-contained and could be refactored for reuse in other PHP applications.

A lightweight wrapper class that converts Chinese characters to Pinyin using the overture/pinyin library. It provides static methods for quick conversion (e.g., Pinyin::get('中国') returns 'zhong guo'). This class is a clean adapter pattern, easily extractable for any PHP project needing Chinese-to-Pinyin conversion.

An abstract driver interface for token storage, with concrete implementations for Mysql and Redis. The driver pattern allows switching token backends without changing consumer code. The Mysql driver stores tokens in a database table with expiration, while Redis uses native TTL. This pattern is reusable across any PHP authentication system needing flexible token persistence.