FunnelKit + Automatic CSS Checkout Fix

FunnelKit + Automatic CSS Checkout Fix

<?php
/**
 * Plugin Name: FunnelKit + Automatic CSS Checkout Fix
 * Description: Disables Automatic CSS on FunnelKit checkout. Add to mu-plugins.
 *
 * Automatic CSS uses a custom Style_Queue (not wp_styles), so wp_dequeue_style() has no effect.
 * The only way is to remove its wp_head callback. We find it by class and unset directly
 * since remove_action requires the exact object reference.
 */
add_action( 'template_redirect', 'funnelkit_disable_automaticcss_on_checkout', 1 );

function funnelkit_disable_automaticcss_on_checkout() {
	if ( ! function_exists( 'is_checkout' ) || ! is_checkout() ) {
		return;
	}
	// FunnelKit override: WFACP_Common::get_id() > 0, or option has override page
	$wfacp_id = class_exists( 'WFACP_Common' ) ? WFACP_Common::get_id() : 0;
	if ( $wfacp_id < 1 ) {
		$g = get_option( '_wfacp_global_settings', array() );
		$wfacp_id = isset( $g['override_checkout_page_id'] ) ? absint( $g['override_checkout_page_id'] ) : 0;
	}
	if ( $wfacp_id < 1 ) {
		return;
	}

	global $wp_filter;
	if ( empty( $wp_filter['wp_head'] ) || ! ( $wp_filter['wp_head'] instanceof \WP_Hook ) ) {
		return;
	}
	$hook = $wp_filter['wp_head'];
	if ( empty( $hook->callbacks[1000000] ) ) {
		return;
	}
	$acss_class = 'Automatic_CSS\Framework\AssetManager\AssetManager';
	foreach ( $hook->callbacks[1000000] as $key => $cb ) {
		if ( ! is_array( $cb['function'] ) || empty( $cb['function'][0] ) ) {
			continue;
		}
		if ( $cb['function'][0] instanceof $acss_class ) {
			remove_action( 'wp_head', $cb['function'], 1000000 );
			return;
		}
	}
}