Multi Crypto Price Converter

A WordPress plugin that displays cryptocurrency prices and performs instant price conversions.

This project demonstrates modern WordPress development practices, bridging the gap between traditional WordPress architecture and modern software engineering principles. It serves as a portfolio piece showcasing Dependency Injection, SOLID principles, and React-based Gutenberg blocks.

🚀 Technical Overview

Architecture

The plugin is architected to be modular, testable, and scalable. It treats WordPress as an application framework, prioritizing clean architecture and separation of concerns.

• Dependency Injection (DI): Utilizes League\Container to manage dependencies. Classes like Admin_Settings and Price_Rest_Controller receive their dependencies (e.g., Crypto_Client_Factory) via constructor injection, making the codebase decoupled and unit-testable.
• SOLID Principles:
  • Single Responsibility: Distinct classes for Settings, API Clients, Caching, and REST Controllers.
  • Open/Closed: The Crypto_Client_Factory allows adding new crypto data sources (e.g., Binance, Coinbase) without modifying existing client logic.
  • Interface Segregation: Clients implement strict interfaces for fetching prices and coin lists.
• Modern PHP (8.0+): Extensively uses strict typing (declare(strict_types=1)), typed properties, constructor property promotion, and named arguments.
• Caching Strategy: Implements a caching layer (PSR-16 style) to store API responses, ensuring the site remains fast and stays within API rate limits.
• Dependency Isolation: Uses php-scoper to isolate the dependencies of the plugin, preventing conflicts with other plugins that might use different versions of the same libraries.

Tech Stack

• Backend: PHP 8.0+, WordPress Plugin API.
• Frontend: React, TypeScript, WordPress Block Editor (Gutenberg).
• Build Tools: Composer (PHP), NPM/Webpack (JS/Assets), PHP-Scoper.
• External API: CoinGecko (Configurable via Factory pattern).

🛠️ Installation & Build

If you are cloning this repository for review or development, follow these steps to build the artifacts.

Prerequisites

• PHP 8.0 or higher
• Composer
• Node.js & NPM

Setup

1. Clone the repository into your WordPress plugins directory:

   cd wp-content/plugins
   git clone https://github.com/c24o/wp-multi-crypto-price-converter.git
   cd wp-multi-crypto-price-converter

2. Install PHP Dependencies: This plugin uses Composer for autoloading and dependency management.

   composer install --no-dev --optimize-autoloader

3. Install & Build Frontend Assets: The React block needs to be compiled.

   npm install
   npm run build:front

4. Activate: Log in to your WordPress admin panel and activate Multi Crypto Price Converter.

📂 Project Structure

multi-crypto-price-converter/
├── src/               # Resource requiring compilation
│   ├── blocks         # React/Gutenberg Block components (TypeScript)
│   ├── js             # Custom scripts (TypeScript)
├── includes/          # PHP Classes
│   ├── Cache/         # Caching logic
│   ├── Clients/       # API Clients (CoinGecko, etc.)
│   ├── Controllers/   # REST API Controllers
│   ├── Entities/      # DTOs (Data Transfer Objects)
│   └── Settings/      # Admin Page logic
├── build/             # Compiled assets (JS/CSS)
├── tests/             # Unit tests
├── vendor/
├── node_modules/
├── multi-crypto-price-converter.php # Plugin entry point
├── composer.json
├── package.json
├── phpcs.xml
├── phpstan.neon
├── scoper.inc.php
├── tsconfig.json
└── README.md

🧪 Code Quality Standards

• WordPress Coding Standards (WPCS): The code follows strict WPCS formatting and best practices.
• Security:
  • Nonces for verification.
  • esc_attr, esc_html for output escaping.
  • sanitize_text_field for input sanitization.
  • Capability checks (current_user_can).
• Performance:
  • Server-side caching of external API calls.
  • Block metadata registration for optimal asset loading (WP 6.7+ standards).