Show one image on a node teaser
Hook_process_field can be used inside template.php to render only one image on a multiple image field.
/**
* Implements hook_process_field().
*/
function MYMODULE_process_field(&$vars) {
switch($vars['element']['#view_mode']) {
// Only on node teaser.
case 'node_teaser':
switch($vars['element']['#field_type']) {
// Only on image fields.
case 'image':
// Only render the first image of a multiple image field.
$vars['items'] = array(reset($vars['items']));
break;
}
break;
}
}