Reply To: Set a field's value to null or other value?

• John Huebner

• October 4, 2019 at 10:42 pm

The first thing you need to do is to set up the two fields

field a = true false field
field b = this field has conditional logic to only show if field a is true, set the default value of field b to whatever you want as the default.

add_action('acf/save_post', 'my_acf_save_post;, 20);
function my_acf_save_post($post_id) {
  if (get_field('field_a', $post_id)) {
    // value is true
    // do nothing, value is set to the default or something new was entered
  } else {
    // value is false
    // you can do one of the following
    // set field b to a default value
    update_field('field_b', 'your value', $post_id);
    // or delete the value of the field
    delete_field('field_b', $post_id);
  }
}