Block Logic – Full Gutenberg Block Display Control

Make good use of WP’s own conditional tags. Use operators to combine conditions. See Supported functions and globals section for allowed functions. Functions are extendable via filters.

1. Operators

   • ! (not) to reverse the logic, eg !is_home() is TRUE when this is NOT the home page.
   • || (or) to combine conditions. X || Y is TRUE when either X or Y is true.
   • && (and) to make conditions more specific. X && Y is TRUE when both X and Y are true.

2. WordPress Conditional Checks

   • is_home() — just the main blog page
   • !is_page('about') — everywhere except this specific WP page
   • is_user_logged_in() — shown when a user is logged in
   • is_category(array(5,9,10,11)) — category page of one of the given category IDs
   • is_single() && in_category('baked-goods') — single post that’s in the “baked-goods” category
   • current_user_can('administrator') — admin-only blocks
   • strpos($_SERVER['HTTP_REFERER'], "google.com") !== false — blocks to show when clicked through from Google
   • is_category() && in_array($cat, get_term_children(5, 'category')) — category page that’s a descendant of category 5
   • in_array(77, get_post_ancestors($post)) — WP page that is a child of page 77
   • is_page('home') || $post->post_parent == 13 — home page or the page that’s a child of page 13

3. WordPress Post & Term Checks

   • has_term('special-offer', 'category', $post) — post has a specific category term
   • get_post_meta(get_the_ID(), 'featured', true) == 'yes' — check a meta field value
   • get_post_type() == 'product' — current post type is a WooCommerce product
   • is_sticky() — sticky posts only
   • has_post_thumbnail() — only posts/pages with a featured image
   • get_the_category() — fetch post categories (can be used in expressions)
   • get_the_tags() — fetch post tags

4. WooCommerce-Specific Checks

   • WC()->cart && WC()->cart->get_cart_contents_count() > 0 — cart has at least one item
   • WC()->cart && WC()->cart->total > 50 — cart total is more than $50
   • is_product() && get_post_meta(get_the_ID(), '_sale_price', true) !== '' — product has a sale price
   • is_product_category('shoes') && WC()->cart — category page “shoes” and cart exists
   • is_user_logged_in() && WC()->cart && WC()->cart->get_cart_contents_count() > 0 — logged-in user and cart has items

5. ACF Checks (Read-only)

   • get_field('featured') == true — ACF field “featured” is true
   • get_sub_field('discount') > 0 — ACF subfield “discount” has a value
   • get_row() > 0 — there are ACF repeater rows
   • get_field_object('product_info')['value'] !== '' — check ACF field object value

6. PHP Helpers

   • in_array('baked-goods', wp_get_post_categories($post)) — category array check
   • strpos(get_permalink($post), 'sale') !== false — check if permalink contains “sale”
   • empty(get_post_meta(get_the_ID(), 'stock', true)) — post has no stock meta
   • count(WC()->cart->get_cart()) > 1 — more than 1 item in cart
   • time() > strtotime('2026-01-01') — check current timestamp
   • number_format(WC()->cart->total, 2) — format cart total
   • round(get_post_meta(get_the_ID(), 'rating', true)) > 4 — rating is greater than 4

Block Logic comes with a set of safe WordPress, WooCommerce, ACF, and PHP helper functions, as well as selected globals and superglobals. These can be used in block logic expressions to control the display of blocks dynamically.

1. Allowed Superglobals

   • By default, only safe, read-only superglobals are available. Developers can extend this list via the block_logic_allowed_superglobals filter.
     • $_GET — query parameters
     • $_POST — submitted form data
     • $_SERVER — server/environment info (e.g., $_SERVER['HTTP_REFERER'])
     • $_COOKIE — cookies

   • Example usage:

     !empty($_GET['ref']) && strpos($_SERVER['HTTP_REFERER'], 'google.com') !== false
     

2. Allowed WordPress Globals

   • These global variables are accessible inside block logic expressions. Extend the list via the block_logic_allowed_globals filter.
     • $post — current post object
     • $wp_query — main query object
     • $wp_the_query — backup of main query
     • $wp — WP environment object
     • $wp_rewrite — rewrite rules
     • $current_user — WP_User object of the current user
     • $wp_version — WordPress version

   • Example usage:

     in_array($post->ID, get_post_ancestors($post)) && is_user_logged_in()
     

3. Allowed WordPress Functions

   • Overview
     • current_user_can('administrator') — check user capabilities
     • get_current_user_id() — current user ID
     • get_option('blogname') — get site title
     • get_post_meta(get_the_ID(), 'featured', true) — read post meta
     • get_post_type() — post type slug
     • get_the_ID() — current post ID
     • has_post_thumbnail() — check if post has featured image
     • is_page('about') — check if current page is “about”

   • Example usage:

     is_page('about') && has_post_thumbnail()
     

4. ACF Functions

   • Overview
     • get_field('featured') — read ACF field value
     • get_sub_field('discount') — read subfield in repeater
     • get_row() — number of repeater rows
     • get_field_object('product_info')['value'] — field object value

   • Example usage:

     get_field('featured') == true && get_sub_field('discount') > 0
     

5. WooCommerce Functions

   • Overview
     • wc_get_cart_contents_count() — number of items in cart
     • wc_get_cart_total() — cart total
     • wc_get_cart_subtotal() — cart subtotal
     • wc_cart_is_empty() — TRUE if cart is empty
     • wc_customer_get_id() — current customer ID
     • wc_customer_get_billing_email() — customer billing email
     • wc_customer_get_shipping_country() — shipping country
     • wc_customer_get_shipping_state() — shipping state
     • wc_customer_get_shipping_postcode() — shipping postcode
     • wc_get_product($product_id) — get WC_Product object

   • Example usage:

     wc_get_cart_contents_count() > 0 && wc_get_cart_total() > 50
     

6. PHP Helpers

   • Overview
     • strpos($haystack, $needle)
     • in_array($needle, $array)
     • empty($var)
     • isset($var)
     • count($array)
     • strlen($string)
     • preg_match($pattern, $subject)
     • current_time('timestamp')
     • strtotime($string)
     • date($format, $timestamp)
     • time()
     • number_format($number, $decimals)
     • round($number)

   • Example usage:

     count(WC()->cart->get_cart()) > 1 && time() > strtotime('2026-01-01')
     

Block Logic provides four filters that developers can use to safely extend which functions, globals, and superglobals are available inside block logic expressions.

1. Add custom functions

   • Use the block_logic_allowed_functions filter to make additional functions available in block logic expressions.

   • Example

     add_filter('block_logic_allowed_functions', function($allowed) {
         $allowed[] = 'my_cart_has_items';
         return $allowed;
     });
     
     function my_cart_has_items() {
         return WC()->cart && WC()->cart->get_cart_contents_count() > 0;
     }
     

   • Usage in a block logic field:

     my_cart_has_items()
     

2. Add extra superglobals

   • Use the block_logic_allowed_superglobals filter to allow additional superglobals like $_SESSION.

   • Example:

     add_filter('block_logic_allowed_superglobals', function($allowed) {
         $allowed[] = '_SESSION';
         return $allowed;
     });
     

   • Usage in a block logic field:

     !empty($_SESSION['special_offer'])
     

3. Add extra WordPress globals

   • Use the block_logic_allowed_globals filter to allow extra global variables.

   • Example:

     add_filter('block_logic_allowed_globals', function($allowed) {
         $allowed[] = 'my_global_data';
         return $allowed;
     });
     
     // Somewhere in your theme or plugin
     $GLOBALS['my_global_data'] = ['foo' => 'bar'];
     

   • Usage in a block logic field:

     $post->ID == my_global_data['foo']
     

4. Add completely custom globals

   • Use the block_logic_extra_globals filter to allow any additional global variable in block logic expressions.

   • Example:

     add_filter('block_logic_extra_globals', function($allowed) {
         $allowed[] = 'my_custom_flag';
         return $allowed;
     });
     
     // Initialize the global somewhere
     $GLOBALS['my_custom_flag'] = true;
     

   • Usage in a block logic field:

     $my_custom_flag && is_user_logged_in()