Here is my PHP code from the ajax/setVideoBroken.php file which returns a Json:

if(isset($_POST["src"])) {
    $query = $con->prepare("UPDATE videos SET broken = 1 WHERE videoLink=:src");
    $query->bindValue(":src", $_POST["src"]);
    $query->execute();
    
    $response = ['success' => false];
    $videoQuery = $con->prepare("SELECT * FROM videos WHERE videoLink=:src");
    $videoQuery->bindValue(":src", $_POST["src"]);
    $videoQuery->execute();
    while($row = $videoQuery->fetch(PDO::FETCH_ASSOC)) {
        $response['success'] = true;
        $response = [
            'success' => true,
            'video_link' => $row["videoLink"],
            'thumbnail' => $row["thumbnail"],
            'video_type' => 'video/' . $row["video_extension"],
        ];  
    }
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode($response);
    exit;
} else {
    echo "No src passed to page";
}

Which Json returned in PHP above, is fetched in Ajax (JavaScript) to display the video_link video link in the source tag which itself is included in the video tag:

function loadVideo(src, className) {
    
    var video = $('<video id="player" playsinline controls><source /></video>');

    video.on("load", function() {
        $("." + className + " a").append(video);

        clearTimeout(timer);

        timer = setTimeout(function() {
            $(".imageResults").masonry();
        }, 500);

    });

    video.on("error", function() {
        
        $("." + className).remove();

        $.post("ajax/setVideoBroken.php", {src: src});

    });
    
    $.post("ajax/setVideoBroken.php", {src: src}, function(response) {
        if(response.success) {
            $('video', $video).attr('data-poster', response.thumbnail);
            $('source', $video)
                .attr('src', response.video_link)
                .attr('type', response.video_type);
        }
    });

}

I want to specify that response.video_link can contain simple video URLs (like: https://website.com/video.mp4) or oEmbed HTML code like that of Youtube (like: <iframe src="https://www.youtube.com/embed/4YCLRpKY1cs?feature=oembed"></iframe>)

So, how to check in JavaScript code:

• If response.video_link (the video_link response of the Json returned by the PHP Code) begins with < which represents the opening sign of the HTML tag ???

• And if Yes (video_link begins with the < sign, it means that video_link is equivalent to an oEmbed type HTML code like that of Youtube), give the value of this HTML code directly to the var video variable.

• If not, we must to pass to the variable var video the code <video id="player" playsinline controls><source /></video> so as to add to the tag source, the link of the video what the JSON response contains: video_link.

I really need your help.