README

Helpers for the WordPress object cache and transients.

Requirements

Make sure all dependencies have been installed before moving on:

• PHP >= 7.1
• Composer

Install

Via Composer:

$ composer require helick/cache-helpers

Usage

The package provides the following functions for WordPress:

• cache_remember()
• cache_forget()
• transient_remember()
• transient_forget()
• site_transient_remember()
• site_transient_forget()

Each function checks the response of the callback for a WP_Error object, ensuring you're not caching temporary errors for long periods of time. PHP Exceptions will also not be cached.

cache_remember()

Get a value from the object cache, if one doesn't exist, run the given callback to generate and cache the value.

Parameters

(string) $key

The cache key.

(callable) $callback

The callback used to generate and cache the value.

(string) $group

Optional. The cache group. Default is empty.

(int) $expire

Optional. The number of seconds before the cache entry should expire. Default is 0 (as long as possible).

Example

use function Helick\CacheHelpers\cache_remember;

function get_latest_posts()
{
    return cache_remember('latest', function () {
        return new WP_Query([
            'posts_per_page' => 5,
            'orderby'        => 'post_date',
            'order'          => 'desc',
        ]);
    }, 'posts', HOUR_IN_SECONDS);
}

cache_forget()

Get and subsequently delete a value from the object cache.

Parameters

(string) $key

The cache key.

(string) $group

Optional. The cache group. Default is empty.

(mixed) $default

Optional. The default value to return if the given key doesn't exist in the object cache. Default is null.

Example

use function Helick\CacheHelpers\cache_forget;

function display_error_message()
{
    $error_message = cache_forget('form_errors', 'my-cache-group', false);

    if ($error_message) {
        echo 'An error occurred: ' . $error_message;
    }
}

transient_remember()

Get a value from the transients, if one doesn't exist, run the given callback to generate and cache the value.

Parameters

(string) $key

The cache key.

(callable) $callback

The callback used to generate and cache the value.

(int) $expire

Optional. The number of seconds before the cache entry should expire. Default is 0 (as long as possible).

Example

use function Helick\CacheHelpers\transient_remember;

function get_tweets()
{
    $user_id = get_current_user_id();
    $key     = 'latest_tweets_' . $user_id;

    return transient_remember($key, function () use ($user_id) {
        return get_latest_tweets_for_user($user_id);
    }, 15 * MINUTE_IN_SECONDS);
}

transient_forget()

Get and subsequently delete a value from the transients.

Parameters

(string) $key

The cache key.

(mixed) $default

Optional. The default value to return if the given key doesn't exist in transients. Default is null.

use function Helick\CacheHelpers\transient_forget;

function display_error_message()
{
    $error_message = transient_forget('form_errors', false);

    if ($error_message) {
        echo 'An error occurred: ' . $error_message;
    }
}

site_transient_remember()

Get a value from the transients, if one doesn't exist, run the given callback to generate and cache the value.

This function shares arguments and behavior with transient_remember(), but works network-wide when using WordPress Multisite.

Parameters

(string) $key

The cache key.

(mixed) $default

Optional. The default value to return if the given key doesn't exist in transients. Default is null.

use function Helick\CacheHelpers\site_transient_remember;

function get_tweets()
{
    $user_id = get_current_user_id();
    $key     = 'latest_tweets_' . $user_id;

    return site_transient_remember($key, function () use ($user_id) {
        return get_latest_tweets_for_user($user_id);
    }, 15 * MINUTE_IN_SECONDS);
}

site_transient_forget()

Get and subsequently delete a value from the site transients.

This function shares arguments and behavior with transient_forget(), but works network-wide when using WordPress Multisite.

Parameters

(string) $key

The cache key.

(mixed) $default

Optional. The default value to return if the given key doesn't exist in transients. Default is null.

use function Helick\CacheHelpers\site_transient_forget;

function display_error_message()
{
    $error_message = site_transient_forget('form_errors', false);

    if ($error_message) {
        echo 'An error occurred: ' . $error_message;
    }
}

Contributing

Please see CONTRIBUTING and CODE_OF_CONDUCT for details.

Security

If you discover any security related issues, please email evgenii@helick.io instead of using the issue tracker.

Credits

• Evgenii Nasyrov
• All Contributors

License

The MIT License (MIT). Please see License File for more information.