Hooks
- Intent
- Build a function/method from multiple components
- Motivation
- Very often we need to decouple or delay definitions until run time
- Implementation
- Implement a methods that allows executing a set of functions at predefined times
- Example
class hooks {
private $cache = array();
function run( $func, $arg ) {
foreach(array('before','at','after') as $hook)
foreach($this->cache[$func][$hook] as $f) { $f($arg); }
}
function hook($hook, $func, $cb) {
$this->cache[$func][$hook][]=$cb
}
function before($func, $cb) {
$this->cache[$func]['before'][]=$cb
}
function at($func, $cb) {
$this->cache[$func]['at'][]=$cb
}
function after($func, $cb) {
$this->cache[$func]['after'][]=$cb
}
function around($hook, $func, $cb) {
$this->cache[$func]['around'][]=$cb
$this->cache[$func]['after'][]=$cb
}
}
//and usage
$hs = new hooks();
$hs->hook('before','label','before_a_func');
$hs->hook('at','label','core');
$hs->run();
//or using the individual methods
$hs = new combinator();
$hs->before('label','before_a_func');
$hs->around('label','tracer');
$hs->run();
