EDD Changelog Enhanced

Enhanced changelog endpoint with semantic HTML, microformats, and SEO optimization for EDD Software Licensing downloads. Designed for iframe embedding.

Overview

EDD Changelog Enhanced replaces the default EDD Software Licensing changelog functionality with a modern, SEO-optimized solution that supports iframe embedding, semantic HTML, and microformats.

Features

• Semantic HTML5 with proper heading hierarchy
• Microformats support for better machine readability
• SEO optimization with meta tags and structured data
• Social media integration with featured image support for Twitter, Facebook, and LinkedIn
• Iframe embedding support with security headers
• Mobile-responsive design
• Print-friendly styling
• Theme override support
• UTF-8 and emoji handling
• Intelligent caching with automatic invalidation
• Sitemap integration with Yoast SEO for changelog URLs (v1.1+)

Requirements

• WordPress 5.0+
• PHP 7.4+
• EDD Software Licensing plugin

Installation

1. Upload the plugin files to /wp-content/plugins/edd-changelog-enhanced/
2. Activate the plugin through the WordPress admin
3. Plugin will automatically enhance existing changelog endpoints

Usage

The plugin automatically registers changelog endpoints for EDD downloads:

/{download-slug}/changelog/

Social Media Integration

When EDD downloads have featured images, the changelog pages automatically include:

• Open Graph meta tags for Facebook and LinkedIn sharing
• Twitter Card metadata with large image preview
• Schema.org ImageObject structured data

Template Override

Themes can override the changelog template by creating:

yourtheme/edd-changelog-enhanced/changelog.php

File Structure

edd-changelog-enhanced/
├── edd-changelog-enhanced.php      # Main plugin file
├── assets/
│   └── css/
│       └── changelog.css           # Responsive styling
└── templates/
    └── changelog.php               # HTML template

Technical Details

Architecture

• Main Class: EDD_Changelog_Enhanced (Singleton)
• Endpoint: Custom rewrite endpoint
• Template System: WordPress template hierarchy with overrides
• Caching System: Simplified version-based caching with plugin version integration
• Sitemap Integration: Automatic changelog URL injection via Yoast SEO filters

Security Features

• Input validation and sanitization
• XSS prevention
• Safe HTML filtering
• Security headers for iframe embedding

SEO Features

• Open Graph and Twitter Card meta tags with featured image support
• Schema.org structured data with ImageObject integration
• Canonical URLs
• Proper heading hierarchy
• Dynamic Twitter card types (summary_large_image when image exists)

Caching System

The plugin uses a simplified, efficient caching strategy:

• Cache Key Format: edd_changelog_{download_id}_{download_version}_{plugin_version}
• Automatic Invalidation: Cache clears when download version or plugin version changes
• Database Storage: Uses WordPress options table (non-autoloaded)
• No Manual Management: No cache key tracking or complex cleanup routines

Cache Lifecycle:

1. Generated HTML is cached using version-based keys
2. Cache automatically becomes invalid when versions change
3. Manual invalidation via WordPress meta update hooks

Sitemap Integration (v1.1+)

The plugin automatically adds changelog URLs to Yoast SEO sitemaps for better search engine discovery:

• Automatic URL Addition: Each download's /changelog/ URL is added to the sitemap (only for downloads that have changelog content)
• Smart Date Detection: Uses the latest version date from changelog as lastmod value
• Proper Formatting: Utilizes Yoast's sitemap_url() method for correct XML structure
• No Images: Changelog entries are marked with empty image arrays (changelogs don't have images)
• Priority Adjustment: Changelog URLs receive slightly lower priority than main download pages

How it works:

1. Hooks into wpseo_sitemap_entry to collect download URLs
2. Parses changelog content to extract latest version date
3. Adds formatted changelog URLs via wpseo_sitemap_download_content filter
4. Each changelog URL includes accurate lastmod based on version release date

Performance

• Simplified HTML caching - Efficient cache keys without content hashing
• Automatic cache invalidation - No stale cache issues from version updates
• HTTP caching with ETags - Version-based ETags for browser cache validation
• Minimal CSS footprint - Optimized styling for fast loading
• Mobile-first responsive design - Optimized for all devices

Development

The plugin follows WordPress coding standards and includes:

• Defensive programming practices
• Extensive input validation
• Error logging for debugging
• Graceful degradation

Changelog Format

The plugin parses changelogs with version headings like:

<h4>1.0.0 on January 1, 2024</h4>
<ul>
<li>🚀 Initial release</li>
<li>✨ New feature added</li>
<li>🐛 Bug fixes</li>
</ul>

Contributing

We welcome contributions from the community! Whether it's bug fixes, new features, documentation improvements, or translations, we appreciate your help in making this plugin better.

How to Contribute

1. Fork the repository on GitHub
2. Create a feature branch from main (git checkout -b feature/amazing-feature)
3. Make your changes and commit them with clear, descriptive messages
4. Test your changes to ensure they work as expected
5. Push to your fork (git push origin feature/amazing-feature)
6. Open a Pull Request with a clear title and description

Guidelines

• Follow WordPress coding standards
• Include proper documentation for new features
• Add tests if applicable
• Keep commits atomic and focused
• Update the README if needed

We'll review your PR as soon as possible and provide feedback. Thank you for contributing!

License

GPL v2 or later

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