AJAX button on table rows to delete rows

Question

I have a standard form with a table. I can add lines to the table via AJAX.
I also like to delete the lines using AJAX. But I don't know exactly where and how to add the buttons.

Here is my code to build the table inside the standard form building function:

  ...
  $aPersonsTable = array();
  foreach ($aPersons as $key => $value) {
    $row = array($value['dname'],'HERE IS THE PLACE WHERE THE BUTTON SHOULD SHOW UP');
    $aPersonsTable[]=$row;
  }

  $form['persons']['ptable'] = array(
    '#theme' => 'table',
    '#header' => $pheader,
    '#rows' => isset($aPersonsTable)?$aPersonsTable:null,
    '#disabled' => TRUE,
    '#title' => 'Users currently assigned',
    '#empty' => t('No users assigned yet!'),
    '#prefix' => '<div id="ptable_wrapper">',
    '#suffix' => '</div>',
  );
  ...

I'd like to have the button at 'HERE IS THE PLACE WHERE THE BUTTON SHOULD SHOW UP' :-)

I tried something like:

$row = array($value['dname'],array(
  '#type' => 'submit',
  '#value'=> 'Delete person',
  '#attributes' => array('id'=>$value['id']),
  '#ajax'=> array(
    'callback' => 'delete_person_ajax_callback',
  )
));

Any ideas? I googled and stackexchanged a lot, but did not find the right solution. Thx.

Answer 1

I found the answer using drupal_render(). The buttons are now generated in each row, havin their own ids, so that I can read the triggering element in the callback function. Now I only have the problem whe I click one of the buttons, the complete form is submitted. There seems to be no ajax callback. I will search further an will the edit the answer...

  foreach (aPersons as $key => $value) {
    $form_button['button'] = array(
      '#id' => 'del_'.$key,
      '#type' => 'button',
      '#value' => 'Delete',
      '#ajax' => array(
        'callback' => 'delete_person_ajax_callback',
      )
    );
    $deleteButton = drupal_render($form_button['button']);
    $row = array($value['dname'],$deleteButton);
    $aPersonsTable[]=$row;
  }

Answer 2

I had the same issue with drupal 8.

The issue occured when several buttons/submits shared the same "#value". Drupal doesn't seem to handle the callbacks correctly in this case.

For me, the solution was to make each button's "#value" unique.

Answer 3

I have fixed the above issues. Button element rendering through theme row data array not using a function like drupal_render(). Each row's theme table passes by reference. The respective row triggers the ajax callback function individually.

foreach ($Persons as $key => $value) {
    $form_button['button_'. $key] = array(
      '#id' => 'del_'.$key,
      '#type' => 'button',
      '#submit' => array('delete_person_button_submit'),
      '#value' => 'Delete',
      '#ajax' => array(
        'callback' => 'delete_person_ajax_callback',
      )
    );
    $row = array('data' => &$form_button['button_'. $key]);
    $aPersonsTable[] = $row;
  }