Caching strategies in Wordpress - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enable page caching in WordPress using a plugin.

Wordpress

<?php
// Activate caching plugin
add_action('init', function() {
    if (!function_exists('[1]')) {
        return;
    }
    [1]();
});

Drag options to blanks, or click blank then click option'

Awp_cache_init

Bstart_cache

Ccache_start

Denable_cache

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent function name.

Confusing caching initialization with cache clearing.

The wp_cache_init function initializes the WordPress caching system. It is used by caching plugins to start caching.

2fill in blank

medium

Complete the code to clear the cache when a post is updated.

Wordpress

<?php
add_action('save_post', function($post_id) {
    if (wp_is_post_revision($post_id)) {
        return;
    }
    [1]();
});

Drag options to blanks, or click blank then click option'

Aclear_cache

Bwp_cache_clear_cache

Cwp_cache_flush

Dflush_cache

Attempts:

3 left

💡 Hint

Common Mistakes

Using a function that does not exist in WordPress.

Trying to clear cache with a function meant for starting cache.

The wp_cache_flush function clears the entire cache in WordPress. It is commonly used after content updates.

3fill in blank

hard

Fix the error in the code to set cache expiration time correctly.

Wordpress

<?php
function set_cache_expiration() {
    $expiration = [1] * 60; // minutes to seconds
    wp_cache_set('cache_expiration', $expiration);
}

Drag options to blanks, or click blank then click option'

A600

B'10'

C10 * 60

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string instead of a number.

Multiplying by 60 twice.

The expiration time should be set as an integer representing minutes. Multiplying by 60 converts minutes to seconds.

4fill in blank

hard

Fill both blanks to create a transient cache with expiration.

Wordpress

<?php
set_transient('[1]', $data, [2]);

Drag options to blanks, or click blank then click option'

A'my_cache_key'

B3600

C60

D'cache_data'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable instead of a string for the key.

Setting expiration time too low or as a string.

The first blank is the cache key as a string. The second blank is the expiration time in seconds (3600 = 1 hour).

5fill in blank

hard

Fill all three blanks to retrieve cached data safely.

Wordpress

<?php
$cache = get_transient([1]);
if ([2] === false) {
    $cache = fetch_data();
    set_transient([3], $cache, 3600);
}

Drag options to blanks, or click blank then click option'

A'my_cache_key'

B$cache

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Using different keys for get and set.

Checking the wrong variable for cache miss.

The cache key is used to get and set the transient. The variable $cache is checked to see if the cache is empty (false).