From b34767750ba5e1e3dc67942d4f42bf0def3e28aa Mon Sep 17 00:00:00 2001
From: Robin Martijn <robin.martijn@expedition.nl>
Date: Sat, 24 Feb 2024 09:47:25 +0100
Subject: [PATCH] feat: add  filter to cache methods (#2878)

Add `timber/cache/transient_key` filter to allow filtering the transient key.

---------

Co-authored-by: Nicolas Lemoine <nico.lemoine@gmail.com>
---
 src/Loader.php              | 38 +++++++++++++++++++++++++++++++++++++
 tests/test-timber-cache.php | 15 +++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/src/Loader.php b/src/Loader.php
index adeeda76a..5c956add5 100644
--- a/src/Loader.php
+++ b/src/Loader.php
@@ -668,6 +668,25 @@ public function get_cache($key, $group = self::CACHEGROUP, $cache_mode = self::C
         $value = false;
         $trans_key = \substr($group . '_' . $key, 0, self::TRANS_KEY_LEN);
 
+        /**
+         * Filters the transient key used for caching.
+         *
+         * @api
+         * @since 2.1.0
+         * @example
+         * ```
+         * add_filter( 'timber/cache/transient_key', function( $trans_key, $key, $group, $cache_mode ) {
+         *     return $trans_key . '_my_suffix';
+         * }, 10, 4 );
+         * ```
+         *
+         * @param string $trans_key The transient key.
+         * @param string $key The cache key.
+         * @param string $group The cache group.
+         * @param string $cache_mode The cache mode.
+         */
+        $trans_key = apply_filters('timber/cache/transient_key', $trans_key, $key, $group, $cache_mode);
+
         if (self::CACHE_TRANSIENT === $cache_mode) {
             $value = \get_transient($trans_key);
         } elseif (self::CACHE_SITE_TRANSIENT === $cache_mode) {
@@ -696,6 +715,25 @@ public function set_cache($key, $value, $group = self::CACHEGROUP, $expires = 0,
         $cache_mode = $this->_get_cache_mode($cache_mode);
         $trans_key = \substr($group . '_' . $key, 0, self::TRANS_KEY_LEN);
 
+        /**
+         * Filters the transient key used for caching.
+         *
+         * @api
+         * @since 2.1.0
+         * @example
+         * ```
+         * add_filter( 'timber/cache/transient_key', function( $trans_key, $key, $group, $cache_mode ) {
+         *     return $trans_key . '_my_suffix';
+         * }, 10, 4 );
+         * ```
+         *
+         * @param string $trans_key The transient key.
+         * @param string $key The cache key.
+         * @param string $group The cache group.
+         * @param string $cache_mode The cache mode.
+         */
+        $trans_key = apply_filters('timber/cache/transient_key', $trans_key, $key, $group, $cache_mode);
+
         if (self::CACHE_TRANSIENT === $cache_mode) {
             \set_transient($trans_key, $value, $expires);
         } elseif (self::CACHE_SITE_TRANSIENT === $cache_mode) {
diff --git a/tests/test-timber-cache.php b/tests/test-timber-cache.php
index 70c2cef7b..40a28bb14 100644
--- a/tests/test-timber-cache.php
+++ b/tests/test-timber-cache.php
@@ -543,6 +543,21 @@ public function testTimberLoaderCacheTransientsButKeepOtherTransients()
         $this->assertSame(2, $wpdb->num_rows);
         $this->assertEquals('foo', get_transient('random_600'));
     }
+
+    public function testCacheTransientKeyFilter()
+    {
+        $filter = function ($key) {
+            return 'my_custom_key';
+        };
+        add_filter('timber/cache/transient_key', $filter);
+
+        $loader = new Timber\Loader();
+        $loader->set_cache('test', 'foobar', \Timber\Loader::CACHE_TRANSIENT);
+
+        remove_filter('timber/cache/transient_key', $filter);
+
+        $this->assertEquals('foobar', get_transient('my_custom_key'));
+    }
 }
 
 class MyFakeThing implements TimberKeyGeneratorInterface