Block Logic – Full Gutenberg Block Display Control

FAQ

Writing Logic Code

Make good use of WP’s own conditional tags. You can vary and combine code using:

• ! (not) to reverse the logic, eg !is_home() is TRUE when this is NOT the home page.
• || (or) to combine conditions. X OR Y is TRUE when either X is true or Y is true.
• && (and) to make conditions more specific. X AND Y is TRUE when both X is true and Y is true.
• 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 category with this slug
• current_user_can('level_10') — admin only blocks
• strpos($_SERVER['HTTP_REFERER'], "google.com")!=false — blocks to show when clicked through from a google search
• is_category() && in_array($cat, get_term_children( 5, 'category')) — category page that’s a descendent of category 5
• global $post; return (in_array(77,get_post_ancestors($post))); — WP page that is a child of page 77
• global $post; return (is_page('home') || ($post->post_parent=="13")); — home page OR the page that’s a child of page 13

Note the extra ‘;’ on the end where there is an explicit ‘return’.

The ‘block_logic_eval_override’ filter

Before the Block Logic code is evaluated for each block, the text of the Block Logic code is passed through this filter. If the filter returns a BOOLEAN result, this is used instead to determine if the block is visible. Return TRUE for visible.

With great power comes great responsibility

The block logic you introduce is EVAL’d directly. Anyone who has access to use the Gutenberg Editor will have the right to add any code, including malicious and possibly destructive functions. There is an optional filter ‘block_logic_eval_override’ which you can use to bypass the EVAL with your own code if needed.

• I’m getting “PHP Parse error… … eval()’d code on line 1”

You have a PHP syntax error in one of your block’s “Block Logic” fields. Review them for errors.