Purge Nginx FastCGI cache automatically when content changes. Comment-safe - comments do NOT trigger cache purges.

Description

Better Nginx Cache intelligently manages your Nginx FastCGI cache by automatically purging it when content actually changes, while excluding comment-related actions that would otherwise cause unnecessary cache invalidation.

Key Features

• Selective Cache Purging - Only purges cache on actual content changes (posts, pages, menus, themes, widgets)
• Comment-Safe - Comments do NOT trigger cache purges, preventing unnecessary cache invalidation on high-traffic sites
• Cache Statistics - View cached file count and total cache size in the admin dashboard
• HTML Footer Comment - Optional attribution displayed as HTML comment in page source
• Admin Bar Integration - Quick "Purge Cache" button in the WordPress admin bar
• Manual Purge - One-click cache purge from the settings page
• Multisite Compatible - Proper cleanup on plugin deletion

Why This Plugin?

Most Nginx cache plugins purge the entire cache whenever a comment is submitted, approved, or moderated. On high-traffic sites, this causes:

• Unnecessary server load regenerating cached pages
• Slower page loads for visitors
• Wasted resources

Better Nginx Cache solves this by only purging when actual content changes - not when users leave comments.

What Triggers Cache Purge

• Posts/pages created, updated, or deleted
• Theme changes
• Navigation menu updates
• Widget modifications
• Site title, tagline, or URL changes

What Does NOT Trigger Cache Purge

• Comment submissions
• Comment approvals
• Comment edits
• Comment deletions
• Trackbacks and pingbacks

Requirements

• Nginx with FastCGI cache configured
• Write access to the cache directory
• PHP 7.4 or higher
• WordPress 5.0 or higher

Installation

1. Upload the better-nginx-cache folder to the /wp-content/plugins/ directory
2. Activate the plugin through the 'Plugins' menu in WordPress
3. Go to Tools → Nginx Cache to configure

Configuration

1. Cache Path: Enter the absolute path to your Nginx FastCGI cache directory (e.g., /var/www/example.com/cache)
2. Auto Purge: Enable/disable automatic cache purging on content changes
3. Cache Footer: Enable/disable the HTML comment footer

Nginx Configuration Example

Your Nginx configuration should include FastCGI caching:

` fastcgi_cache_path /var/www/example.com/cache levels=1:2 keys_zone=example:100m inactive=24h;

In your server block:

fastcgi_cache example; fastcgi_cache_valid 200 301 24h; fastcgi_cache_key "$scheme$request_method$host$request_uri"; `

Frequently Asked Questions

Why don't comments trigger cache purges?

This is by design. On high-traffic sites, comments can be frequent. Purging the entire cache for every comment causes unnecessary server load. The cached page will naturally refresh based on your Nginx inactive setting.

Can I add custom actions that trigger purges?

Yes! Use the bnc_purge_actions filter:

add_filter( 'bnc_purge_actions', function( $actions ) { $actions[] = 'my_custom_action'; return $actions; } );

Can I exclude certain post types from triggering purges?

Yes! Use the bnc_excluded_post_types filter:

add_filter( 'bnc_excluded_post_types', function( $types ) { $types[] = 'revision'; return $types; } );

Does this work with Redis Object Cache?

Yes! Better Nginx Cache works alongside Redis Object Cache. They handle different caching layers:

• Nginx FastCGI Cache = Full HTML page caching
• Redis Object Cache = Database query caching

Does this work with Cloudflare?

Yes! Cloudflare sits in front of Nginx. This plugin manages your origin server's Nginx cache.

My cache path shows an error

Ensure:

1. The path exists on your server
2. The web server user (www-data, nginx, etc.) has write permissions
3. The path points to a valid Nginx cache directory with levels=1:2 structure

Screenshots

1. Settings page with cache statistics
2. Admin bar with quick purge option
3. Cache statistics sidebar

Changelog

1.0.2

• SECURITY: Fixed potential XSS vulnerability in settings page author link (now uses wp_kses)
• FIXED: Corrected "Purge Triggers" list to accurately reflect implemented triggers
• IMPROVED: Removed unused clear_stats_cache() method from BNC_Cache_Stats class
• Code cleanup and WordPress Plugin Review Team compliance improvements

1.0.1

• FIXED: Cache now reliably persists - no more unexpected purges
• IMPROVED: Replaced multiple aggressive hooks (save_post, edit_post, delete_post) with transition_post_status for precise control
• IMPROVED: Autosaves, drafts, and revisions no longer trigger cache purges
• IMPROVED: Cache only purges when posts are actually published, updated, unpublished, or trashed
• IMPROVED: Removed option update hooks that caused excessive purging
• IMPROVED: Added did_action() check to prevent duplicate hook registrations
• FIXED: Changed purge flag from instance variable to static variable for reliable single-purge per request
• NEW: Added bnc_should_purge_on_status_change filter for fine-grained control
• NEW: Added bnc_should_purge filter for non-post purge triggers

1.0.0

• Initial release
• Selective cache purging (excludes comments)
• Cache statistics tracking
• HTML footer comment with attribution
• Admin bar integration
• Settings page under Tools menu
• Full multisite support
• Internationalization ready

Upgrade Notice

1.0.2

Security fix: Addresses XSS vulnerability in settings page. Recommended update for all users.

1.0.1

Important reliability fix: Cache no longer gets deleted unexpectedly. Autosaves, drafts, and revisions no longer trigger purges.

1.0.0

Initial release of Better Nginx Cache.

Developer Hooks

Filters

bnc_purge_actions - Modify the list of non-post WordPress actions that trigger cache purges.

bnc_excluded_post_types - Exclude specific post types from triggering cache purges.

bnc_should_purge_on_status_change - Fine-grained control over whether to purge for specific post status transitions. Receives $should_purge, $new_status, $old_status, $post.

bnc_should_purge - Control whether non-post triggers should purge the cache.

Actions

bnc_cache_purged - Fires after the cache has been purged. Receives the cache path as parameter.