Caching data in WordPress is easy. Caching data in WordPress in a good and performant way takes a bit more work. For instance, many developers commonly use the Transients API to cache data. As the lowest common denominator in caching, this is okay. It'll get the job done, even on a $10/year shared hosting plan. But what [...]
Page Generation Graph for WordPress
At work, one of the more interesting customizations we have on WordPress.com for our VIP clients is a dashboard that contains custom widgets. One of them is a page generation graph that shows the average page generation time for their site compared to all others. That way they can judge their code performance against a [...]
Quick Tip: DreamHost cron and WP-CLI
If you're hosting your WordPress website on DreamHost, and use their cron system to offload your WordPress faux-cron for better reliability, be careful of what version of PHP you have in your code. I recently had an issue where my cron events weren't firing, and after enabling email output, I ended up with something like this PHP [...]
Blogging Anonymously
An interesting problem I came across recently was how to set up a WordPress blog with an anonymous user. Now, a simple way would be to create a brand new user with fake information, but that's too easy. After looking for some prior art, I found the Anonymizer plugin in the WordPress.org plugin repository. Unfortunately, it's [...]
Logging Failed Redirects
WordPress has a built-in function called wp_safe_redirect(). This allows you to create redirects in code, but only to whitelisted domains (via the allowed_redirect_hosts filter). The downside to this is that you have to remember to whitelist the domains. It's easy to forget if you're doing a lot of redirects, for instance with the WPCOM Legacy Redirector [...]
Purging All The Caches!
One of the best ways to ensure that a WordPress site--well any site really--stays performant and not broken is by leveraging caching. WordPress by default doesn't do much caching other than some in-memory caching of objects, and the odd database caching via the Transients API. This site currently has three layers of caching: PHP OPcache [...]
Quick Tip: Viewing Headers With Curl
Something that I do often at work is to check HTTP headers for random things such as redirects, cache headers, proxies, ssl, etc. A common way this is done is by using the -I (--header) switch: $ curl -I http://example.com/ HTTP/1.1 200 OK Content-Encoding: gzip Accept-Ranges: bytes Cache-Control: max-age=604800 Content-Type: text/html Date: Wed, 27 Jun 2018 [...]
Disabling WordPress Faux Cron
The WordPress WP-Cron system is a decently okay faux cron system, but it has its problems, such as running on frontend requests and not running if no requests are coming through. WP-Cron works by: on every page load, a list of scheduled tasks is checked to see what needs to be run. Any tasks scheduled [...]
Quick Tip: Force Enable Auto-Updates in WordPress
I know that auto-updates are a bit of a (#wpdrama) touchy subject, but I believe in them. In an mu-plugin I enable all auto-updates like so: <?php // Turn on auto-updates for everything if ( ! defined( 'IS_PRESSABLE' ) || ! IS_PRESSABLE ) { add_filter( 'allow_major_auto_core_updates', '__return_true' ); add_filter( 'allow_minor_auto_core_updates', '__return_true' ); } add_filter( 'auto_update_core', '__return_true' [...]
Query Caching (and a little extra)
By default, WordPress does not cache WP_Query queries. Doing so can greatly improve performance. The way I do this is via the Advanced Post Cache plugin: https://github.com/Automattic/advanced-post-cache By running this plugin (hopefully as an mu-plugin) with a persistent object cache, WP_Query calls, along with get_post() calls (only if suppress_filters is false) will be cached. Bonus! Now that we're caching queries, [...]