Loop form in PHP, Submit all forms with 1 button

Question

I have a question. I want to make a history timeline, on this timeline the user can add 'elements' (eg a element for each year.).

In form 1 the user creates timeline and says the amount of elements on the timeline this gets send to the database (this works). In form 2 the user can fill the elements. (This doesnt work).

In form 1 (if someone wants 5 elements) after posting, the database creates 5 records (for each element one).

Now I want 5 different forms that fills these 5 elements (Title, description etc.), but with 1 submit button.

Now if i try this (see code below), only the 5th form gets posted... How do I get this to work?

Thanks in advance,

<?php

error_reporting(E_ALL);
ini_set('display_errors', 1);

require_once('classes/database.class.php');

$DB = Database::getInstance();

$titel = '';
$beschrijving = '';
$afbeeldingURL = '';
$jaar = '';
$element_id = '';

$velden = '';

$sql3 = "SELECT `id` , `aantal_elementen` FROM `tijdlijn` ORDER BY id DESC LIMIT 0, 1";
$last_id = $DB->_query($sql3);

if ($last_id->num_rows > 0) {
    while($row = $last_id->fetch_assoc()) {
        $last_id2 = $row["id"]; 
        $aantal_elementen3 = $row["aantal_elementen"];
    }
}

$sql4 = "SELECT * FROM `elementen` WHERE `tijdlijn_id` = ".$last_id2."";

$sql5 = "SELECT `id` FROM `elementen` WHERE `tijdlijn_id` = ".$last_id2." ORDER BY id ASC LIMIT 0,1";

$sql6 = "SELECT `id` FROM `elementen` WHERE `tijdlijn_id` = ".$last_id2." ORDER BY id DESC LIMIT 0,1";

$sql7 = "SELECT `id` FROM `elementen` WHERE `tijdlijn_id` = ".$last_id2." ORDER BY id ASC";

$last_id3 = $DB->_query($sql4);

$min_id = $DB->_query($sql5);
$min_id = mysqli_fetch_assoc($min_id);
$min_id = $min_id['id'];

$max_id = $DB->_query($sql6);
$max_id = mysqli_fetch_assoc($max_id);
$max_id = $max_id['id'];

$dingid[] = $DB->_query($sql7);

echo $min_id."</br>";
echo $max_id."</br>";
$current_id = $min_id;

if (isset($_POST) && !empty($_POST)) {

    $boolError = false;

    foreach ($_POST as $k => $v) {
        $_POST[$k] = trim($v);
    }

    if (!isset($_POST['titel']) || trim($_POST['titel']) == '') {
        $titel    = 'error';
       $boolError = true;
    }

    if (!isset($_POST['beschrijving']) || trim($_POST['beschrijving']) == '') {
        $beschrijving = 'error';
        $boolError = true;
    } 

    if (!isset($_POST['afbeeldingURL']) || trim($_POST['afbeeldingURL']) == '') {
    } 

    if (!isset($_POST['jaar']) || trim($_POST['jaar']) == '') {
        $jaar_start  = 'error';
        $boolError = true;
    } 

    if (
        !isset($_POST['element_id'])
        || trim($_POST['element_id']) == ''
        || !preg_match('/^\d+$/', $_POST['element_id'])
    ) {
        $element_id  = 'error';
        $boolError = true;
    } 


    if ($boolError === false) {
        $sql = "UPDATE `elementen`
                SET
                `titel` = '" . $_POST['titel'] . "',
                `beschrijving` = '" . $_POST['beschrijving'] . "',
                `afbeelding_url` = '" . $_POST['afbeeldingURL'] . "',
                `jaar` = '" . $_POST['jaar'] . "'
                WHERE `id` = ".$_POST['element_id'].";
        ";


        if ($DB->_query($sql)) {
         //$current_id++;
         //exit;


        } else {
            header('Location: ?oops2');
           exit;

        }

    } else {
        $velden = "Ff alles invullen he";
    }
?> <p>Vul het formulier hier onder in voor de elementen en maak een tijdlijn!</p><?php
} 

     if ($last_id3->num_rows > 0) {
        while($row2 = $last_id3->fetch_assoc()) {
            $last_id4 = $row2["id"]; 
?>


        <form class="form-nieuws" method="post">

            </br></br>
            <?php echo $last_id2; ?>
            <?php echo $current_id; ?>
            <input id="titel2" class="<?= $titel ?> form-control" type="text" placeholder="Titel tijdlijn" name="titel" value="<?= isset($_POST['titel']) ? $_POST['titel'] : '' ?>">
            <br>
            <textarea id="beschrijving2" class="<?= $beschrijving ?> form-control" rows="3" placeholder="Beschrijving over tijdlijn" name="beschrijving" value="<?= isset($_POST['beschrijving']) ? $_POST['beschrijving'] : '' ?>"></textarea>
            <br>
            <input id="afbeeldingURL2" class="<?= $afbeeldingURL ?> form-control" type="text" placeholder="URL voor afbeelding" name="afbeeldingURL" value="<?= isset($_POST['afbeeldingURL']) ? $_POST['afbeeldingURL'] : '' ?>">
            <br>            
            <input id="jaar" class="<?= $jaar ?> form-control" type="text" placeholder="Start jaar tijdlijn" name="jaar" value="<?= isset($_POST['jaar']) ? $_POST['jaar'] : '' ?>">
             <input id="element_id" class="<?= $element_id ?> form-control" type="text" placeholder="<?php echo $last_id4 ?>" name="element_id" value="<?= isset($_POST['element_id']) ? $_POST['element_id'] : '' ?>">
            <div class="foutlabel">
                <em class="<?= ($velden) ? 'error' : '' ?>"><?= ($velden) ? $velden : '' ?>
                </em>
            </div>
            </br>    


                     <?php $current_id++;} 

                     } ?> <div class="gabutton">
                <input type="submit" value="Creeer tijdlijn">
            </div>


        </form>

Answer 1

The best way is to have only one form with input for each elements. You generate each form input in function of your elements.

With this way, you only have one button and one call to send data to your server.

In server side, you just need to parse and check data and be carefull about number of element you send.