How to send data to custom block content - drupal-7

Question

I'm trying to create a module that will display some last entries from database. I'd like to send last entry object to template file (guestbook-last-entries.tpl.php), that looks like that
<p><?php render($title); ?></p>
<?php echo $message; ?>
I have a function that implements hook_theme
function guestbook_theme() {
return array(
'guestbook_last_entries' => array(
'variables' => array(
'entries' => NULL,
),
'template' => 'guestbook-last-entries'
),
);
}
one that do preprocess
function template_preprocess_guestbook_last_entries(&$variables) {
$variables = array_merge((array) $variables['entries'], $variables);
}
and functions that implements hook_block_view
function guestbook_block_view($delta = '') {
switch ($delta) {
case 'guestbook_last_entries':
$block['subject'] = t('Last entries');
$block['content'] = array();
$entries = guestbook_get_last_entries(variable_get('guestbook_m', 3));
foreach ($entries as $entry) {
$block['content'] += array(
'#theme' => 'guestbook_last_entries',
'#entries' => $entry,
);
}
break;
}
return $block;
}
function that gets data from database
function guestbook_get_last_entries($limit = 3) {
$result = db_select('guestbook', 'g')
->fields('g')
->orderBy('posted', 'DESC')
->range(0, $limit)
->execute();
return $result->fetchAllAssoc('gid');
}
But in this case I get only one entry displayed. Can anyone tell me how to resolve this, how should I build that $block['content']?
Thank you

Answer 1

This here wont work:
$block['content'] += array(
'#theme' => 'guestbook_last_entries',
'#entries' => $entry,
);
Maybe you want this if you need an array as the result:
// note that I replaced += with a simple = and added two brackets that will create a new element in that array $block['content']
$block['content'][] = array(
'#theme' => 'guestbook_last_entries',
'#entries' => $entry,
);