modifier.php

         <?php
$mysqli = new mysqli('localhost', 'root', '', 'base_test_modal') or die('die');

if(isset($_POST['submit'])){
    $id = $_POST['id'];
    $title = $_POST['title'];
    $text = $_POST['text'];
    $urls = $_POST['url'];
    $i = (int)$_POST['id'];

    if (verifTitle($title) && verifText($text)){

        $idRequest=$mysqli->query("SELECT GROUP_CONCAT(DISTINCT id SEPARATOR ',') as ids FROM `domain` WHERE `id_text_modal` =".mysqli_real_escape_string($mysqli, $_REQUEST['id'])." GROUP BY id_text_modal");
        $iR = $idRequest->fetch_object();
        $index = $iR->ids;
        if (verifurl($urls)) {
            if (update($mysqli, $urls, $text, $title, $id))
            {
                delete($mysqli, $index);
                header("Location: http://demo.local?tag=modifiersuccess");
            }
        }
    }
}
$modalRequest = $mysqli->query('SELECT * FROM `modal` WHERE `modal`.`id` = '.mysqli_real_escape_string($mysqli, $_REQUEST['id']));
$modal = $modalRequest->fetch_object();
$urlsRequest = $mysqli->query('SELECT * FROM `domain` WHERE `domain`.`id_text_modal` = '.$_GET['id']);
$formUrl=[];
while ($url = $urlsRequest->fetch_object())
{
    array_push($formUrl,$url->url);
}
?>
    <!DOCTYPE html>
    <html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
    <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script>
    <script>
        $( document ).ready(function() {
            $( "#addUrl" ).bind( "click", function( event ) {
                $("#divUrl").append('<input type="text" name="url[]" /><br/>');
            });
        })
    </script>
</head>
<body>
<div class="container">
    <?php
    $modalTitle=$modal->title;
    $modalText=$modal->text_modal;
    if (!empty($_POST)){
        $modalTitle=$_POST['title'];
        $modalText=$_POST['text'];
    }
    ?>
    <form class="form-group" action="" method="POST">
        TITLE MODAL: <input class="form-control" type="text" name="title" value="<?php echo $modalTitle; ?>"/>
        <?php
        if (isset($_POST['submit'])){if (!verifTitle($title)){echo" il y a un erreur dans le champ Titre<br/>";};}
        ?>
        TEXT MODAL: <textarea class="form-control" name="text" ><?php echo $modalText; ?> </textarea>
        <?php
        if (isset($_POST['submit'])){if (!verifText($text)){echo" il y a un erreur dans le champ Text<br/>";};}
        if (!empty($_POST)) {
            $formUrl= $_POST['url'];
        }
        foreach ($formUrl as $url){
            ?>
            URL MODAL: <input class="form-control" type="text" name="url[]" value="<?php echo $url; ?>"/><br/><br/>
            <?php

        }
        ?>
        <input type="hidden" name="id" value="<?php echo $modal->id; ?>">
        <div id="divError"><?php if (isset($_POST['submit'])){if (!verifurl($urls)){echo" il y a un erreur dans le champ Url";}} ?></div>
        <input class="btn btn-outline-secondary" type="button" value="Ajouter une url" id="addUrl">

        <div id="divUrl">

        </div>

        <input class="btn btn-primary" type="submit" name="submit" value="soumettre"><br/>
    </form>
</div>
</body>
<?php
function verifTitle($title)
{

    if ($title=="")
    {

        return false;
    }
    return true;
};
function verifText($text)
{
    if ($text=="")
    {

        return false;
    }
    return true;
};
function verifurl($urls)
{
    foreach ($urls as $url)
    {
        if (!filter_var($url, FILTER_VALIDATE_URL))
        {
            return false;
        }

    }
    return true;
};
function update($mysqli,$urls,$text,$title,$id)
{
    foreach ($urls as $url)
    {
        $stmt = $mysqli->prepare("INSERT INTO `domain` (`url`, `id_text_modal`) VALUES (?,?) ");
        $stmt->bind_param('ss', $url, $id);
        $stmt->execute();
    }
    $stmt2 = $mysqli->prepare("UPDATE  `modal` SET `text_modal`=?, `title`=?  WHERE `id` =?  ");
    $stmt2->bind_param('ssi', $text, $title, $id);
    $stmt2->execute();
    $stmt->close();
    $stmt2->close();
    return true;
};
function delete($mysqli,$iR)
{
   var_dump($iR);

    $stmt = $mysqli->prepare("DELETE FROM `domain` WHERE  `id` IN (?)");
    var_dump($stmt);

   var_dump($stmt->bind_param('s',$iR));
    $stmt->execute();
    exit();
    $mysqli->close();
};