Pagination for entities

Question

I have an entity called announcement, and I have a page (user/%/announcement) where I display a table of three columns (name of entity,an edit entity link and an delete entity link).

function announcements_user($account) {
  $uid = $account->uid;
  $return = '';
  $total = 0;
  $i=0;
  $pid = array();
  $text = array();

  $query = db_select('announcements','a')->extend('PagerDefault');
  $query->fields('a',array('pid','value'));
  $query->condition('uid', $uid);
  $result = $query->execute();

  foreach($result as $row) {
    $pid[] = $row->pid;
    $text[] = $row->value;  
    $total++;
  }

  $return .= '<table border="1">
    <tr>
     <th>Announcement</th>
     <th>Edit</th>
     <th>Delete</th>
    </tr>';

  while ($total) {
    $return .= '<tr>';
    $return .= '<td><a href="'.$base_url.'/announcement/'.$pid[$i].'">'.substr($text[$i],0,10).'......</a></td>';
    $return .= '<td><a href="'.$base_url.'/announcement/edit/'.$pid[$i].'">Edit</a></td>';
    $return .= '<td><a href="'.$base_url.'/announcement/delete/'.$pid[$i].'">Delete</a></td>';
    $return .= '</tr>';
    $i++;
    $total--;
  } 

  $return .='</table>';
  $return .='<br>';
  $return .='<a href ="'.$base_url.'/announcement/add">Add Announcement</a>';

  return $return;   
}

Now my problem is that keeping this format of tabular structure, how do I display my result in a paginated format with 5 announcements per page? I have seen pager.inc for Drupal 7 and howto-print-out-the-pagination-for-entityfieldqueries link, but I just can't figure out how to apply them to my case.

Answer 1

function announcements_user($account) {
  $header = array(
    'announcement' => array(t('Announcement')),
    'operations' => array('data' => t('Operations'), 'colspan' => '2'),
  );
  $rows = array();

  $result = db_select('announcements','a')
    ->fields('a', array('pid','value'))
    ->condition('uid', $account->uid)
    ->extend('PagerDefault')
    ->limit(5)
    ->execute();

  foreach ($result as $data) {
    $row = array();
    $row[] = l(truncate_utf8($data->value, 10, FALSE, TRUE), 'announcement/' . $data->pid);
    $row[] = l(t('Edit'), 'announcement/edit/' . $data->pid);
    $row[] = l(t('Delete'), 'announcement/delete/' . $data->pid);

    $rows[] = $row;
  }

  $form['announcements'] = array(
    '#theme' => 'table', 
    '#header' => $header, 
    '#rows' => $rows, 
    '#empty' => t('No announcement available.'),
  );

  $form['pager'] = array('#markup' => theme('pager'));
  return $form;
}

• Query methods generally return the object for which they are invoked; this means that method calls can be concatenated as I did in the code.
• PagerDefault::limit() has a default limit of 10; if you don't call that method, the limit is the default value.
• Strings that appear in the user interface should always be translated; the only strings that cannot be translated (which means, you cannot pass them to t()) are dynamic strings obtained from a function/method.
• Drupal URLs should always be obtained from url() or l(). l() returns the HTML tag for links (<a>), while url() returns the relative or absolute URL for the Drupal path passed as argument.

For an example of function that does something similar, see blog_page_last(), which returns the last blog posted by a user.