Observer
- Intent
- When an object changes, notify all interested parties
- Motivation
- events, synchronisation, ...
- Implementation
- Use hooks pattern at and after to implement the observer
- No implementation needed in the Subject class
- Example
//initialisation
$hs = new hooks();
$observer = new interested_party();
$change_method = array($object, 'setter');
//setup change point(can be done externally from $change method)
$hs->at('change', $change_method);
//express interest
$hs->after('change', array($obesrver, 'callback'));
$hs->run($arg);
- Note
- The precise implementation of the hooks may differ, depending on functionality, abstraction, sugar, ... Have a look at the drupal hooks as well.
