我很难理解wp\\u send\\u json\\u error如何返回错误消息。只要不满足任何错误条件，它就可以正常工作。但如果出现错误，则不会返回任何内容。

如何返回中设置的错误消息wp_send_json_error() 何时出现错误？

查看我的代码：

function submit_youtube_callback() {
    check_ajax_referer( \'randomnonce\', \'security\' );

    if (    !isset($_POST[\'post_id\']) || 
            !is_numeric($_POST[\'post_id\']) || 
            !get_post_status($_POST[\'post_id\']) || 

            !isset($_POST[\'yt_url\']) ||
            !isset($_POST[\'terms\'])
            ) {

        wp_send_json_error( \'Error: Invalid data!\' );
    }

    // Check if terms are checked
    $terms = $_POST[\'terms\'];
    if ( $terms != true ) {
        wp_send_json_error( \'Error: You must accept the terms.\' );
    }

    // Check if valid youtube URL   
    $youtube_url = $_POST[\'yt_url\'];
    $preg = \'~^(?:https?://)?(?:www\\.)?(?:youtube\\.com|youtu\\.be)/watch\\?v=([^&]+)~x\';
    $has_match = preg_match($preg, $youtube_url, $matches); 
    if ( empty($matches[1]) ) {
        wp_send_json_error( \'Error: You did not enter a valid YouTube URL.\');
    }   

    echo \'<p>youtube: \'. $youtube_url .\'</p>\';  
    echo \'<p>terms accepted: \' . $terms .\'</p>\';

    wp_die();
} add_action( \'wp_ajax_cp_narrations_callback\', \'submit_youtube_callback\' );

function submit_youtube_javascript() {
    if ( is_single() ) {

        $ajax_nonce = wp_create_nonce( "randomnonce" );

        ?>
        <script>
            ( function( $ ) {
                var ajaxurl = "<?php echo admin_url(\'admin-ajax.php\'); ?>",
                    submit_youtube = $(\'#submitYouTubeForm\');

                // Star rating button
                $(submit_youtube).on(\'submit\', function(event) {
                    event.preventDefault();

                    var submit_youtube_url = $(\'#submitYouTubeURL\').val(),
                    submit_youtube_terms = $(\'#youtube_terms\').is(\':checked\');

                    // Data to be sent to function
                        var data = {
                            \'action\': \'submit_youtube_callback\',
                            \'security\': \'<?php echo $ajax_nonce; ?>\',
                            \'post_id\': <?php echo get_the_ID(); ?>,

                            \'yt_url\': submit_youtube_url,
                            \'terms\': submit_youtube_terms
                        };

                        // Send Data
                        jQuery.post(ajaxurl, data, function(response) {
                            submit_youtube.replaceWith(response);
                        });                     
                });
            } )( jQuery );
        </script> 
        <?php
    }
} add_action( \'wp_footer\', \'submit_youtube_javascript\', 100 );