Flexible Content – Notice: Undefined index: ID

• paulmist

• April 7, 2020 at 9:58 pm

I’ve been adding to the plugin ‘ACF Flexible Content Preview’.

I added code to be able to retrieve keys from nested fields. It works well but leaves and error in the WP Admin on page using/editing Custom Fields.

Error: Notice: Undefined index: ID in /wp-content/plugins/advanced-custom-fields-pro/includes/acf-field-functions.php on line 361

The function is:

    <?php
    /**
     * Get all ACF flexible content field layout keys
     *
     * TODO: Add caching?
     *
     * @return array
     */
    public function retrieve_flexible_keys() {
        $keys   = [];
        $groups = acf_get_field_groups();
        if ( empty( $groups ) ) {
            return $keys;
        }

        foreach ( $groups as $group ) {
            $fields = (array) acf_get_fields( $group );
            if ( empty( $fields ) ) {
                continue;
            }

            foreach ( $fields as $field ) {
                if ( 'flexible_content' === $field['type'] ) {

                    // Flexible is recursive structure with sub_fields into layouts
                    foreach ( $field['layouts'] as $layout_field ) {
                        if ( ! empty( $keys [ $layout_field['key'] ] ) ) {
                            continue;
                        }
                        $keys[ $layout_field['key'] ] = $layout_field['name'];

                        $sub_fields = (array) acf_get_fields($layout_field);

                        foreach( $sub_fields as $sub_field ) {
                            
                            if( 'flexible_content' === $sub_field['type'] ) {
                                foreach( $sub_field['layouts'] as $layout_sub_field ) {
                                    if ( ! empty( $keys [ $layout_sub_field['key'] ] ) ) {
                                        continue;
                                    }
                                    $keys[ $layout_sub_field['key'] ] = $layout_sub_field['name'];
                                }
                            }
                        }
                    }
                }
            }
        }

        return $keys;
    }
    ?>

I think the problematic line is $sub_fields = (array) acf_get_fields($layout_field);

Help appreciated.