Files
iTop/sources/Service/Events/EventService.php

390 lines
11 KiB
PHP

<?php
/*
* @copyright Copyright (C) 2010-2023 Combodo SARL
* @license http://opensource.org/licenses/AGPL-3.0
*/
namespace Combodo\iTop\Service\Events;
use Closure;
use Combodo\iTop\Service\Events\Description\EventDescription;
use Combodo\iTop\Service\Module\ModuleService;
use ContextTag;
use CoreException;
use DBObject;
use Exception;
use ExecutionKPI;
use ReflectionClass;
use utils;
/**
* Event driven extensibility.
* Inspired by [PSR-14: Event Dispatcher](https://www.php-fig.org/psr/psr-14).
* Adapted to iTop needs in terms of event filtering (using event source or context).
*
* @package EventsAPI
* @api
* @since 3.1.0
*/
final class EventService
{
/** @var array */
private static array $aEventListeners = [];
/** @var int */
private static int $iEventIdCounter = 0;
/** @var array */
private static array $aEventDescriptions = [];
/**
* Initialize the Event Service. This is called by iTop.
*
* @internal
* @return void
*/
public static function InitService()
{
$aEventServiceSetup = utils::GetClassesForInterface(iEventServiceSetup::class, '', ['[\\\\/]lib[\\\\/]', '[\\\\/]node_modules[\\\\/]', '[\\\\/]test[\\\\/]']);
foreach ($aEventServiceSetup as $sEventServiceSetupClass) {
/** @var \Combodo\iTop\Service\Events\iEventServiceSetup $oEventServiceSetup */
$oEventServiceSetup = new $sEventServiceSetupClass();
$oEventServiceSetup->RegisterEventsAndListeners();
}
}
/**
* Register a callback for a specific event
*
* **Warning** : be ultra careful on memory footprint ! each callback will be saved in {@see aEventListeners}, and a callback is
* made of the whole object instance and the method name ({@link https://www.php.net/manual/en/language.types.callable.php}).
* For example to register on DBObject instances, you should better use {@see DBObject::RegisterCRUDListener()}
*
* @uses aEventListeners
*
* @api
* @param string $sEvent corresponding event
* @param callable $callback The callback to call
* @param array|string|null $sEventSource event filtering depending on the source of the event
* @param mixed $aCallbackData optional data given by the registrar to the callback
* @param array|string|null $context context filter
* @param float $fPriority optional priority for callback order
*
* @return string registration identifier
*
* @see DBObject::RegisterCRUDListener() to register in DBObject instances instead, to reduce memory footprint (callback saving)
*
* @since 3.1.0 method creation
* @since 3.1.0-3 3.1.1 3.2.0 N°6716 PHPDoc change to warn on memory footprint, and {@see DBObject::RegisterCRUDListener()} alternative
*/
public static function RegisterListener(string $sEvent, callable $callback, $sEventSource = null, array $aCallbackData = [], $context = null, float $fPriority = 0.0, $sModuleId = ''): string
{
if (!is_callable($callback, false, $sName)) {
return false;
}
$aEventCallbacks = self::$aEventListeners[$sEvent] ?? [];
$sId = 'event_'.self::$iEventIdCounter++;
$aEventCallbacks[] = array(
'id' => $sId,
'event' => $sEvent,
'callback' => $callback,
'source' => $sEventSource,
'name' => $sName,
'data' => $aCallbackData,
'context' => $context,
'priority' => $fPriority,
'module' => $sModuleId,
);
usort($aEventCallbacks, function ($a, $b) {
$fPriorityA = $a['priority'];
$fPriorityB = $b['priority'];
if ($fPriorityA == $fPriorityB) {
return 0;
}
return ($fPriorityA < $fPriorityB) ? -1 : 1;
});
self::$aEventListeners[$sEvent] = $aEventCallbacks;
$sSource = self::GetSourcesAsString($sEventSource);
EventServiceLog::Trace("Registering Listener '$sName' for event '$sEvent' source '$sSource' from '$sModuleId'");
return $sId;
}
/**
* @return false|string
*/
public static function GetListenersAsJSON()
{
return json_encode(self::$aEventListeners, JSON_PRETTY_PRINT);
}
/**
* Fire an event. Call all the callbacks registered for this event.
*
* @api
* @param \Combodo\iTop\Service\Events\EventData $oEventData
*
* @throws \Exception from the callback
*/
public static function FireEvent(EventData $oEventData)
{
$sEvent = $oEventData->GetEvent();
if (!self::IsEventRegistered($sEvent)) {
$sError = "Fire event error: Event $sEvent is not registered";
EventServiceLog::Error($sError);
throw new CoreException($sError);
}
$eventSource = $oEventData->GetEventSource();
$sLogEventName = "$sEvent - ".self::GetSourcesAsString($eventSource).' '.json_encode($oEventData->GetEventData());
EventServiceLog::Trace("Fire event '$sLogEventName'");
if (!isset(self::$aEventListeners[$sEvent])) {
return;
}
$oLastException = null;
$sLastExceptionMessage = null;
$bEventFired = false;
foreach (self::GetListeners($sEvent, $eventSource) as $aEventCallback) {
if (!self::MatchContext($aEventCallback['context'])) {
continue;
}
$sName = $aEventCallback['name'];
EventServiceLog::Debug("Fire event '$sLogEventName' calling '$sName'");
$bEventFired = true;
try {
$oEventData->SetCallbackData($aEventCallback['data']);
$oKPI = new ExecutionKPI();
call_user_func($aEventCallback['callback'], $oEventData);
if (isset($aEventCallback['callback'][1]) && !$oKPI->ComputeStatsForExtension($aEventCallback['callback'][0], $aEventCallback['callback'][1], "Event: $sEvent")) {
$sSignature = ModuleService::GetInstance()->GetModuleMethodSignature($aEventCallback['callback'][0], $aEventCallback['callback'][1]);
$oKPI->ComputeStats('FireEvent', "$sEvent callback: $sSignature");
}
}
catch (EventException $e) {
EventServiceLog::Error("Event '$sLogEventName' for '$sName' id {$aEventCallback['id']} failed with blocking error: ".$e->getMessage());
throw $e;
}
catch (Exception $e) {
$sLastExceptionMessage = "Event '$sLogEventName' for '$sName' id {$aEventCallback['id']} failed with non-blocking error: ".$e->getMessage();
EventServiceLog::Error($sLastExceptionMessage);
$oLastException = $e;
}
}
if ($bEventFired) {
EventServiceLog::Debug("End of event '$sLogEventName'");
}
if (!is_null($oLastException)) {
EventServiceLog::Error("Throwing the last exception caught: $sLastExceptionMessage");
throw $oLastException;
}
}
/**
* @param string $sEvent
* @param $eventSource
*
* @return array
*/
public static function GetListeners(string $sEvent, $eventSource = null): array
{
$aListeners = [];
if (isset(self::$aEventListeners[$sEvent])) {
foreach (self::$aEventListeners[$sEvent] as $aEventCallback) {
if (EventHelper::MatchEventSource($aEventCallback['source'], $eventSource)) {
$aListeners[] = $aEventCallback;
}
}
}
return $aListeners;
}
private static function MatchContext($registeredContext): bool
{
if (empty($registeredContext)) {
return true;
}
if (is_string($registeredContext)) {
$aContexts = array($registeredContext);
} elseif (is_array($registeredContext)) {
$aContexts = $registeredContext;
} else {
return false;
}
foreach ($aContexts as $sContext) {
if (ContextTag::Check($sContext)) {
return true;
}
}
return false;
}
private static function GetSourcesAsString($srcRegistered): string
{
if (empty($srcRegistered)) {
return '';
}
if (is_string($srcRegistered)) {
return substr($srcRegistered, 0, 30);
}
if (is_array($srcRegistered)) {
return substr(implode(',', $srcRegistered), 0, 30);
}
return '';
}
/**
* Unregister a previously registered callback
*
* @param string $sId the callback registration id
*/
public static function UnRegisterListener(string $sId)
{
$bRemoved = self::Browse(function ($sEvent, $idx, $aEventCallback) use ($sId) {
if ($aEventCallback['id'] == $sId) {
$sName = self::$aEventListeners[$sEvent][$idx]['name'];
unset (self::$aEventListeners[$sEvent][$idx]);
EventServiceLog::Trace("Unregistered callback '$sName' id $sId' on event '$sEvent'");
return false;
}
return true;
});
if (!$bRemoved) {
EventServiceLog::Trace("No registration found for callback '$sId'");
}
}
/**
* Unregister all the listeners for an event
*
* @param string $sEvent event to unregister
*/
public static function UnRegisterEventListeners(string $sEvent)
{
if (!isset(self::$aEventListeners[$sEvent])) {
EventServiceLog::Trace("No registration found for event '$sEvent'");
return;
}
unset(self::$aEventListeners[$sEvent]);
EventServiceLog::Trace("Unregistered all the callbacks on event '$sEvent'");
}
/**
* Unregister all the events
*/
public static function UnRegisterAll()
{
self::$aEventListeners = [];
self::$aEventDescriptions = [];
self::$iEventIdCounter = 0;
EventServiceLog::Trace("Unregistered all events");
}
/**
* Browse all the registrations
*
* @param \Closure $callback function($sEvent, $idx, $aEventCallback) to call (return false to interrupt the browsing)
*
* @return bool true if interrupted else false
*/
private static function Browse(closure $callback): bool
{
foreach (self::$aEventListeners as $sEvent => $aCallbackList) {
foreach ($aCallbackList as $idx => $aEventCallback) {
if (call_user_func($callback, $sEvent, $idx, $aEventCallback) === false) {
return true;
}
}
}
return false;
}
/**
* Register an event.
* This allows to describe all the events available.
* This step is mandatory before firing an event.
*
* @api
* @param \Combodo\iTop\Service\Events\Description\EventDescription $oEventDescription
*
* @return void
*/
public static function RegisterEvent(EventDescription $oEventDescription)
{
$sEvent = $oEventDescription->GetEventName();
$sModule = $oEventDescription->GetModule();
if (self::IsEventRegistered($sEvent)) {
$sPrevious = self::$aEventDescriptions[$sEvent]['module'];
EventServiceLog::Warning("The Event $sEvent defined by $sModule has already been defined in $sPrevious, check your delta");
return;
}
self::$aEventDescriptions[$sEvent] = [
'name' => $sEvent,
'description' => $oEventDescription,
'module' => $sModule,
];
}
/**
* @param string $sClass
*
* @return array
* @throws \ReflectionException
* @throws \ReflectionException
* @throws \ReflectionException
*/
public static function GetEventsByClass(string $sClass): array
{
$aRes = [];
$oClass = new ReflectionClass($sClass);
foreach (self::$aEventDescriptions as $sEvent => $aEventInfo) {
if (is_array($aEventInfo['description']->GetEventSources())) {
foreach ($aEventInfo['description']->GetEventSources() as $sSource) {
if (class_exists($sSource) && ($sClass == $sSource || $oClass->isSubclassOf($sSource))) {
$aRes[$sEvent] = $aEventInfo;
}
}
}
}
return $aRes;
}
/**
* Check is an event is already registered.
* Can be used to avoid exception when firing an unregistered event.
*
* @api
* @param string $sEvent
*
* @return bool
*/
public static function IsEventRegistered(string $sEvent): bool
{
return array_key_exists($sEvent, self::$aEventDescriptions);
}
/**
* @return false|string
*/
public static function GetDefinedEventsAsJSON()
{
return json_encode(self::$aEventDescriptions, JSON_PRETTY_PRINT);
}
}