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<?php
namespace dokuwiki\Extension;
/**
* The Action plugin event
*/
class Event
{
// public properties
public $name = ''; // READONLY event name, objects must register against this name to see the event
public $data = null; // READWRITE data relevant to the event, no standardised format (YET!)
public $result = null; // READWRITE the results of the event action, only relevant in "_AFTER" advise
// event handlers may modify this if they are preventing the default action
// to provide the after event handlers with event results
public $canPreventDefault = true; // READONLY if true, event handlers can prevent the events default action
// private properties, event handlers can effect these through the provided methods
protected $_default = true; // whether or not to carry out the default action associated with the event
protected $_continue = true; // whether or not to continue propagating the event to other handlers
/**
* event constructor
*
* @param string $name
* @param mixed $data
*/
public function __construct($name, &$data)
{
$this->name = $name;
$this->data =& $data;
}
/**
* @return string
*/
public function __toString()
{
return $this->name;
}
/**
* advise functions
*
* advise all registered handlers of this event
*
* if these methods are used by functions outside of this object, they must
* properly handle correct processing of any default action and issue an
* advise_after() signal. e.g.
* $evt = new dokuwiki\Plugin\Doku_Event(name, data);
* if ($evt->advise_before(canPreventDefault) {
* // default action code block
* }
* $evt->advise_after();
* unset($evt);
*
* @param bool $enablePreventDefault
* @return bool results of processing the event, usually $this->_default
*/
public function advise_before($enablePreventDefault = true)
{
global $EVENT_HANDLER;
$this->canPreventDefault = $enablePreventDefault;
$EVENT_HANDLER->process_event($this, 'BEFORE');
return (!$enablePreventDefault || $this->_default);
}
public function advise_after()
{
global $EVENT_HANDLER;
$this->_continue = true;
$EVENT_HANDLER->process_event($this, 'AFTER');
}
/**
* trigger
*
* - advise all registered (<event>_BEFORE) handlers that this event is about to take place
* - carry out the default action using $this->data based on $enablePrevent and
* $this->_default, all of which may have been modified by the event handlers.
* - advise all registered (<event>_AFTER) handlers that the event has taken place
*
* @param null|callable $action
* @param bool $enablePrevent
* @return mixed $event->results
* the value set by any <event>_before or <event> handlers if the default action is prevented
* or the results of the default action (as modified by <event>_after handlers)
* or NULL no action took place and no handler modified the value
*/
public function trigger($action = null, $enablePrevent = true)
{
if (!is_callable($action)) {
$enablePrevent = false;
if (!is_null($action)) {
trigger_error(
'The default action of ' . $this .
' is not null but also not callable. Maybe the method is not public?',
E_USER_WARNING
);
}
}
if ($this->advise_before($enablePrevent) && is_callable($action)) {
if (is_array($action)) {
list($obj, $method) = $action;
$this->result = $obj->$method($this->data);
} else {
$this->result = $action($this->data);
}
}
$this->advise_after();
return $this->result;
}
/**
* stopPropagation
*
* stop any further processing of the event by event handlers
* this function does not prevent the default action taking place
*/
public function stopPropagation()
{
$this->_continue = false;
}
/**
* may the event propagate to the next handler?
*
* @return bool
*/
public function mayPropagate()
{
return $this->_continue;
}
/**
* preventDefault
*
* prevent the default action taking place
*/
public function preventDefault()
{
$this->_default = false;
}
/**
* should the default action be executed?
*
* @return bool
*/
public function mayRunDefault()
{
return $this->_default;
}
}
|
