by calling outputHeader(). To produce XML, it uses the XML_WBXML_ContentHandler class which, despite its name, has nothing to do with WBXML but creates plain XML output. If the desired output is WBXML, XML_WBXML_Encoder is used. It has the same interface as the XML_WBXML_ContentHandler but produces WBXML.
Most of the business logic is inside !SyncML_Sync class. During one sync session more than one database can be synced, like calendar and address book. The !SyncML_Sync class handles the Sync of exactly one database. It is setup by the Alert command and then does most of the processing when responding to the Sync command.
For more details about the SyncML protocol see the SyncML spec at http://www.openmobilealliance.org/tech/affiliates/syncml/syncmlindex.html.
The document SyncML Sync Protocol, v1.1 (pdf) is the most relevant one: it describes how a sync session works.
The test framework
The test framework consists of a test script and individual test cases. A test case for SyncML is basically a recording of a successful sync session. The testsync.php script can then replay such a recording by sending the recorded client requests to the SyncML package and check if the response matches the one in the original recording. Actually the test script has to do quite a bit of magic to make this work: it has to simulate entries in the backend so the server returns them on the next sync and it has to adapt between newly created IDs and IDs used in the recording.
The big advantage of the test framework is that a test case recorded with one backend can be used with any other backend implementation. So when developing a new backend, you can use the test framwork to verify that your implementation is correct.
How to setup a simple SyncML server
Setting up a simple SyncML server using the SyncML package and the Sql backend is as simple as this:
- Install pear packages for MDB2 and MDB2 database drivers:
pear install MDB2_Driver_mysql MDB2_Driver_mysql
- Install the SyncML package and the XML_WBXML package from http://pear.horde.org:
pear channel-discover pear.horde.org; pear install --force -c pear.horde.org SyncML XML_WBXML
- If you want to use the Funambol clients, you also need iCalendar, String and NLS:
pear install --force -c pear.horde.org iCalendar String NLS
- Create a database in your database engine (like mysql) as described in Backend/Sql.php:
require_once 'SyncML.php';
// Backend Setup:
$backend = 'Sql';
$backend_parms = array('dsn' => 'mysql://syncml:password@localhost/syncml', // adjust as required
'debug_dir' => '/tmp/sync', // debug output to this dir, must be writeable be web server
'debug_files' => true, // log all (wb)xml packets received or sent to debug_dir:
'log_level' => PEAR_LOG_DEBUG); // log everything
// Not all phpinstalls have http_raw_post_data set, ini-config needed.
// Is it also deprecated in later versions? Well, php://input works.
if( isset($GLOBALS['HTTP_RAW_POST_DATA']) )
$input = $GLOBALS['HTTP_RAW_POST_DATA'];
else
$raw_post = file_get_contents('php://input');
$response = SyncML_HandleRequest($input, $_SERVER['CONTENT_TYPE'], $backend, $backend_parms);
if (is_a($response, 'PEAR_Error')) {
header('HTTP/1.0 500 Internal Server Error');
exit;
}
/* Return the response to the client. */
header('Content-Type: ' . $_SERVER['CONTENT_TYPE']);
header('Content-length: ' . strlen($response));
header('Accept-Charset: UTF-8');
echo $response;
Where to get the SyncML package
The SyncML package is part of the Horde framework. At the moment you have to download the framework from htt://www.horde.org to obtain the SyncML and WBXML packages. It'll be included in the pear channel server as soon as possible to allow installation using the PEAR installer.
If you have any questions, send me a message to karsten at horde _dot_ org.