How to access user-submitted values from a dynamic form?

Question

I want to insert a row in my db-table with inputs from users. The form the users fill out is made with a foreach-loop:

foreach ($results as $row) {
    echo '<div class="vm_kampe"><input type="hidden" name="kid['.$row->id.'" value="'.$row->id.'">'.$row->hhold.' - '.$row->uhold.'</div>
          <div class="vm_result"><input type="text" class="vm_resultat" name="resu['.$row->id.'" placeholder="?-?" value="'.$row->resu.'"></div>
          <div class="vm_1x2"><input type="text" class="vm_1x2" name="bet['.$row->id.'" placeholder="1X2" value="'.$row->bet.'"></div>';
};

On the receiving-end, I tried this, but doesn't work:

$jinput = JFactory::getApplication()->input;
$id = $jinput->get('kid');
$resu = $jinput->getString('resu');
$bet = $jinput->getString('bet');
$uid = $user->id;
$liga = 'bs';

foreach ($id as $key => $k) {
    $columns = array('id', 'uid', 'liga', 'resu', 'bet');
    $values = array($db->quote($k), $db->quote($uid), $db->quote($liga), $db->quote($resu[$key]), $db->quote($bet[$key]));
    $query->insert($db->quoteName('tip3_kuponer'))->columns($columns)->values(implode(',', $values));
    $db->setQuery($query);
    $db->execute();
};

It just say something about:

invalid argument in foreach....

Answer 1

First, you need to repair your damaged form html

// see the missing closing square bracket on each of your name attr ---↓-------------------↓-↓
                                                                       ↓                   ↓ ↓
echo '<div class="vm_kampe"><input type="hidden" name="kid['.$row->id.'←                   ↓ ↓
      <div class="vm_result"><input type="text" class="vm_resultat" name="resu['.$row->id.'← ↓
      <div class="vm_1x2"><input type="text" class="vm_1x2" name="bet['.$row->id.'←-----------

Because it is producing a one-dimensional $_GET (SUPERGLOBAL) array like:

$_GET = array(
    'kid[1' => '1',
    'resu[1' => 'somethingA',
    'bet[1' => 'somethingB',
    'kid[2' => '2',
    'resu[2' => 'somethingC',
    'bet[2' => 'somethingD',
    etc.
);

but really, you want:

$_GET = array(
    'kid' => array('1' => '1', '2' => '2', etc.),
    'resu' => array('1' => 'somethingA', '2' => 'somethingC', etc.),
    'bet' => array('1' => 'somethingB', '2' => 'somethingD', etc.)
);

So I'll recommend this loop code block (using more lines to improve readability of my answer):

foreach ($results as $row) {
    echo '<div class="vm_kampe">';
        echo '<input type="hidden" name="kid[' , $row->id , ']" value="' , $row->id , '">';
        echo $row->hhold , ' - ' , $row->uhold;
    echo '</div>';
    echo '<div class="vm_result">';
        echo '<input type="text" class="vm_resultat" name="resu[' , $row->id , ']" placeholder="?-?" value="' , $row->resu , '">';
    echo '</div>';
    echo '<div class="vm_1x2">';
        echo '<input type="text" class="vm_1x2" name="bet[' , $row->id , ']" placeholder="1X2" value="' , $row->bet , '">';
    echo '</div>';
}  // remove the trailing semi-colon here

Second, change your submission method

Because you are delivering user-supplied data which will be saved to the database, POST is best/common practice versus GET.

Third, collect and process the multi-dimensional $_POST data

(I didn't test this advice)

$kids = JFactory::getApplication()->input->post->get('kid', [], 'array');
$resus = JFactory::getApplication()->input->post->get('resu', [], 'array');
$bets = JFactory::getApplication()->input->post->get('bet', [], 'array');

// just a general example of accessing the sets of data...
foreach ($kids as $id => $kid) {
    echo "For $id, kid is $kid, resu is {$resu[$id]}, bet is {$bet[$id]}<br>";
}

You should be able to integrate your query with the above.

When Joomla 4.0 rolls out, your INSERT query will be a perfect candidate for a single prepared statement with bound parameters, and iterated executions.