7.4:dev:architecture:events

Events - processing of events

TODO: Expand the introduction

An event mechanism has been designed to make extending and overlapping of the CzechIdM core functionality within any module possible.

The event (EntityEvent) is published via EntityEventManager from different places in the application (⇒ hook). A number of processors can react to the event (AbstractEntityEventProcessor) in a defined order (number ⇒ the smaller it is, the sooner the processor is run). Processors run synchronously at default and in one transaction (see next section). Processors with the same order will be run in a random order (OrderComparator) - it's good practice to design and set different processor's order (think about it in design). Instead of the annotation @Order, the method getOrder needs to be overloaded (see the example). Event content could be any Serializable object, but AbstractDto descendant is preferred - see original source lifecycle feature. Event content is required, event without content couldn't exist.

  • event is created with given content <code java> EntityEvent<IdmIdentityDto> event = new IdentityEvent(IdentityEventType.UPDATE, updateIdentity); </code>
  • then is published via EntityEventManager <code java> EventContext<IdmIdentityDto> context = entityEventManager.process(event); </code>
  • when event is published and their content is descendant of AbstractDto, then original source is filled to the event - original source contains previously persisted (original) dto and could be used in "check modification" processors. If event creating new dto, then original source is null. Original source could be set externally - then no automatic filling occurs.
  • returning context contains results from all reacting processors in defined processors order.
  • the processor can label the event as (closed) or (suspended) and therefore skip all the other processors. If the suspended event is published again via EntityEventManager, the processing will continue where it was suspended, if context (with processed results) is preserved. If the processing of the event is (suspended), the called method should return the adequate accepted state.
  • when event walk through processors, then event's processed order is incremented - this order is used after event suspending and run again - event processing will continue with processor with next order.

Supported events for individual entities:

  • IdmIdentityDto - operation with the identity
  • IdmRoleDto - operation with the role
  • IdmRoleCatalogueDto - operation with the role catalogue
  • IdmIdentityRoleDto- assigning a role to the user
  • IdmIdentityContractDto - labor-law relation
  • IdmRoleTreeNodeDto - automatic role
  • IdmTreeNodeDto - tree structure node
  • IdmPasswordPolicyDto - password policy
  • SysSystemDto - System in ACC module
  • SysSystemMappingDto - Mapping between system in ACC and his mapping of provisioning or sync
  • SysSchemaAttributeDto - Connector schema on system in ACC module
  • SysProvisioningOperationDto - provisioning operation (ACC)
  • SysSyncConfigDto, SysSyncItemLogDto - synchronization in ACC module
  • VsRequestDto - Request for account change in virtual system (VS module)

A page has been created directly in the application on the module page for an overview of all entity types and event types migrating through event processing. All the registered processors including the configuration are listed there:

The default order for listeners (- ⇒ before, + ⇒ after):

  • core: 0
  • provisioning: 1000

Event is published with content and specific event type (e.g. CREATE, PASSWORD). Processors can be register by content type and event type - e.g. process event with IdmIdentityDto content and event type CREATE ⇒ other event contents and other event types will not be processed by this processor.

Event types has to be compared by their string representation, NOT by instance. Concrete event types e.q. IdentityEventType are used for documentation reason only - which domain type supports which event. Event types can be added in different modules with different type, but processor can react across all module (⇒ is registered to string event type representation eventType.name()).

...
EntityEvent<IdmIdentityDto> event = new CoreEvent<IdmIdentityDto>(CoreEventType.CREATE, identity);
if (IdentityEventType.CREATE.name() == event.getType().name()) {
 // do something
}
...
  • EntityEvent - an event migrating through the processors. The content of the event can be BaseEntity, BaseDto or any serializable content.
  • EventContext - holds the context of the processed event - which processors it has been processed by, with what results, if the processing is suspended, closed, etc.
  • EventResult - the result of processing of the event by one processor.
  • EntityEventProcessor - event processor. Processor has to have unique identifier by module.
  • EntityEventManager - ensures publishing of the event to processors.
  • EventableDtoService - adds event processing support to service
  • AbstractEntityEvent - an abstract event migrating through the processors - when adding a proper one can be simply inherited from.
  • DefaultEventContext - the default context of the processed event - all abstract and default events and processors use it.
  • DefaultEventResult - The default event result processed by one processor - all abstract and default events and processors use it.
  • AbstractEntityEventProcessor - abstract event processor - when adding a proper one can be simply inherited from.
  • AbstractApprovableEventProcessor - the event processor will send the whole event with dto (or serializable) content to WF for approval. It is necessary to configure the definition of the WF where the event will be sent to.
  • DefaultEntityEventManager - ensures publishing of the events to processors.
  • AbstractEventableDtoService - adds default event processing support to service.

Transactional processing is controlled before the event publishing itself - the whole processing now takes place in a transaction and all processors run synchronously. In case of an error in any processor, the whole transaction is rolled back, which has some advantages:

  • simple adding of validation or referential integrity
  • repeating the whole chain

and disadvantages as well:

  • having to catch all the exceptions properly to avoid "breaking the chain"
  • saving logs and archives in the new transaction (Propagation.REQUIRES_NEW)
  • 0 - basic / core functionality - operation save, delete etc.
  • 100 - automatic roles computation
    • 1000 - after save provisioning.
    • -1000 - before delete provisioning (before identity role is deleted).
    • Identity:
      • -2000 - validate password in acc module - checks all system password policies and idm default policy ⇒ all policies are evaluated in one request. If acc module is enabled, then core password validation processor can be disabled.
      • -1000 - validate password in core module - checks idm default policy.
      • 100 - persist password
    • Provisioning:
      • -5000 - check disabled system
      • -1000 - compute attributes for provisioning (read attribute values from target system)
      • -500 - check readonly system
      • 0 - execute provisioning (create / update / delete)
      • 1000 - execute after provisioning actions (e.g. sends notifications)
      • 5000 - archive processed provisioning operation.

    Other orders can be found directly in application, see supported event types.

Processors can be configured through Configurable interface by standard application configuration.

##
## approve create automatic role
idm.sec.core.processor.role-tree-node-create-approve-processor.enabled=true
# wf definition 
idm.sec.core.processor.role-tree-node-create-approve-processor.wf=approve-create-automatic-role
##
## approve delete automatic role
idm.sec.core.processor.role-tree-node-delete-approve-processor.enabled=true
# wf definition 
idm.sec.core.processor.role-tree-node-delete-approve-processor.wf=approve-delete-automatic-role
  • Check if defined fields on identity was changed. If yes, then send notification.
  • As default is used this system template identityMonitoredFieldsChanged.
  • Extended attributes is not supported now.
  • Order of processor is Integer.Max - 100. We want to send notification on end of chain (after identity is presisted or provisioning are completed).
# Identity changed monitored fields - Check if defined fields on identity was changed. If yes, then send notification.
# Default is disabled
idm.sec.core.processor.identity-monitored-fields-processor.enabled=false
# Monitored fields on change (for Identity, extended attributes are not supported)
idm.sec.core.processor.identity-monitored-fields-processor.monitoredFields=firstName, lastName
# Notification will be send to all identities with this role
idm.sec.core.processor.identity-monitored-fields-processor.recipientsRole=superAdminRole
  • Name of processor "role-request-approval-processor".
  • This process ensures the approval of the request for change permissions.
# Default is enabled
idm.sec.core.processor.role-request-approval-processor.enabled=true
# Workflow process for change permissions (as default is "approve-identity-change-permissions")
idm.sec.core.processor.role-request-approval-processor.wf=approve-identity-change-permissions
  • The approving task will be assigned to all users with role Helpdesk.
# The role can be changed in the application configuration "idm.sec.core.wf.approval.helpdesk.role", the default setting is Helpdesk.
idm.sec.core.wf.approval.helpdesk.role=Helpdesk
# Default is disabled
idm.sec.core.wf.approval.helpdesk.enabled=false
  • The approving task will be assigned to all users evaluated as the managers of the applicant. The manager is defined based on the industrial relations of the applicant.
# Default is disabled
idm.sec.core.wf.approval.manager.enabled=false
  • The approving task will be assigned to all users with role Usermanager.
# The role can be changed in the application configuration "idm.sec.core.wf.approval.usermanager.role", the default setting is Usermanager.
idm.sec.core.wf.approval.usermanager.role=Usermanager
# Default is disabled
idm.sec.core.wf.approval.usermanager.enabled=false

If I want to get myself hooked after deleting the identity, I should implement a processor to the event type IdentityEventType.DELETE with an order number higher than 0:

@Enabled(ExampleModuleDescriptor.MODULE_ID)
@Component("exampleLogIdentityDeleteProcessor")
@Description("Log after identity is deleted")
public class LogIdentityDeleteProcessor extends AbstractEntityEventProcessor<IdmIdentityDto> {
 
	/**
	 * Processor's identifier - has to be unique by module
	 */
	public static final String PROCESSOR_NAME = "log-identity-delete-processor";
	private static final org.slf4j.Logger LOG = org.slf4j.LoggerFactory
			.getLogger(LogIdentityDeleteProcessor.class);
 
	public LogIdentityDeleteProcessor() {
		// processing identity DELETE event only
		super(IdentityEventType.DELETE);
	}
 
	@Override
	public String getName() {
		// processor's identifier - has to be unique by module
		return PROCESSOR_NAME;
	}
 
	@Override
	public EventResult<IdmIdentityDto> process(EntityEvent<IdmIdentityDto> event) {
		// event content - identity
		IdmIdentityDto deletedIdentity = event.getContent();
		// log
		LOG.info("Identity [{},{}] was deleted.", deletedIdentity.getUsername(), deletedIdentity.getId());
		// result
		return new DefaultEventResult<>(event, this);
	}
 
	@Override
	public int getOrder() {
		// right after identity delete
		return CoreEvent.DEFAULT_ORDER + 1;
	}
}