如何将functions.php中的$cert_url传递到WordPress自定义页面使用

第一步：修改functions.php中的逻辑，将生成的证书链接持久化存储 #

你当前写的get_cert_url函数仅在触发woocommerce_thankyou钩子时返回链接，没有做存储，其他页面自然无法直接调用这个变量。只需要在生成$cert_url后将它存入订单自定义字段即可：

add_action( 'woocommerce_thankyou', 'get_cert_url' );
function get_cert_url( $order_id ) {
    global $wpdb;
    $msf_campaign_status = array('wc-completed');
    $msf_campaign_detail = get_post_meta($order_id);
    $msf_campaign_fund = $msf_campaign_detail['msf_charity_fund'][0];
    $order = wc_get_order( $order_id );
    if( $order->has_status('processing') ){
        $name_on_e_cert = str_replace(" ", "+", $msf_campaign_detail['name_on_e_cert'][0]);
        $msf_charity_name = get_option('wc_fields_billing');
        if($msf_campaign_detail['charity_organizations'][0] == 'msf_charity_1'){
            $charity_name = $msf_charity_name['charity_organizations']['options']['msf_charity_1'];
        }
        elseif ($msf_campaign_detail['charity_organizations'][0] == 'msf_charity_2') {
            $charity_name = $msf_charity_name['charity_organizations']['options']['msf_charity_2'];
        }
        elseif ($msf_campaign_detail['charity_organizations'][0] == 'msf_charity_3') {
            $charity_name = $msf_charity_name['charity_organizations']['options']['msf_charity_3'];
        }
        elseif ($msf_campaign_detail['charity_organizations'][0] == 'msf_charity_4') {
            $charity_name = $msf_charity_name['charity_organizations']['options']['msf_charity_4'];
        }
       $donateto = str_replace(" ", "+", $charity_name);
        $subtotal = $order->get_subtotal();
        $amount = (($subtotal*25)/100);
        $request = wp_remote_retrieve_body(wp_remote_get('https://www.api_website.com.my/api/c/product.ashx?key=api_key&orderid='.$order_id.'&name='.$name_on_e_cert.'&donateto='.$donateto.'&amount='.$amount.''));
        $data = json_decode($request);
    
        $result[]= $data;
        
        foreach($result[0] as $line) {
          $cert_url = $line;
        }
        // 新增：将生成的证书链接存入订单自定义字段
        update_post_meta($order_id, 'generated_cert_url', $cert_url);
        return $cert_url;
    }
}

第二步：自定义页面中调用存储的证书链接 #

首先你需要在自定义页面中先获取对应订单的ID（如果是 WooCommerce 感谢页的自定义模板，可以直接拿到全局的$order_id变量；如果是用户中心的订单详情页，也可以从当前查询参数中获取订单ID），再调用get_post_meta读取之前存的链接即可：

// 先获取对应订单ID，以下为示例，请根据你的页面实际场景调整获取方式
$order_id = get_query_var('order-received');
// 读取证书链接
$cert_url = get_post_meta($order_id, 'generated_cert_url', true);
// 链接存在才渲染分享按钮
if($cert_url):
?>
<a href="https://www.facebook.com/sharer?u=<?php echo urlencode($cert_url); ?>&t=Digital-Certificate" target="_blank" rel="noopener noreferrer">Share this on Facebook</a>
<?php endif; ?>

注意事项 #

• 输出链接到Facebook分享参数时记得用urlencode()转义，避免特殊字符导致链接失效
• 如果你的自定义页面和订单没有直接关联，可以考虑把链接存在用户的元数据中，或者通过URL参数传递订单ID来获取对应链接

内容的提问来源于stack exchange，提问作者Boon