The autocompletion function uses a combination of Javascript / AJAX and PHP.
A Javascript script must call a PHP script every time there is a change in the search input. One way to do so is to use jQuery's UI autocomplete feature, with the remote datasource option activated. More information about this option can be found at http://jqueryui.com/autocomplete/#remote.
The role of said PHP script is to call OpenSearchServer to get search suggestions, and return them to the Javascript script. In a typical use case these would be encoded in JSON.
Here is an example of such a PHP script:
require_once(dirname(__FILE__).'/oss_api.class.php');
require_once(dirname(__FILE__).'/oss_autocompletion.class.php');
$oss_url = 'http://localhost:9090';
$oss_index = 'my_index';
$oss_login = 'my_login';
$oss_key = '98hg72de4f27cefbcb7a771335b98735e'
$keywords = (isset($_GET['q'])) ? $_GET['q'] : '';
if(!empty($keywords)) {
$search = new OssAutocompletion($oss_url, $oss_index, $oss_login, $oss_key);
$result = $search->autocomplete($keywords, 20); //ask for 20 suggestions
$result = str_replace("\r\n", "\n", $result);
$result_array = explode("\n", $result); //this API returns data in plain text, one suggestion per line
$count = count($result_array)-1;
for($i=0;$i<$count;$i++) {
$completions[] = array('value' => $result_array[$i]);
}
return json_encode($completions); //encodes the array in JSON to facilitate its use in Javascript
}
return '';