BPM-3 Advanced Workflow Deep Dive

Advanced Workﬂow: Deeper Dive! Nick Smith! Senior Software Engineer, Services Team, Alfresco!

Agenda!Service Tasks •  Java Delegate Class! •  Java Delegate Bean! •  Arbitrary Expressions!Listeners •  Execution Listeners! •  Task Listeners!Scripting •  Scope Variables! •  Execution Variables! •  Examples!TimersQuestions

Service Tasks !

Service Tasks! •  Service Tasks allow Java code to be executed as part of a workﬂow! •  Allows easy unit testing and code re-use! •  Three ways to implement:! •  JavaDelegate Class! •  JavaDelegate Bean:! •  Arbitrary Expression!

Service Tasks: Java Delegate Class! •  The supplied class must implement JavaDelegate interface! •  Fields can be set on the class! •  Use the ʻactiviti:classʼ attribute to specify the delegate class <serviceTask id=“getMimetypet" name=“Get Mimetype” activiti:class="org.alfresco.examples.MimetypeGetter“ > <extensionElements> <activiti:field name=“document"> <activiti:expression>${dcwkflw_document}</activiti:expression> </activiti:field> </extensionElements> </serviceTask>

Service Tasks: Java Delegate Bean! •  The supplied bean must implement JavaDelegate interface! •  The same bean instance is used for all executions! •  The bean must be deﬁned in Spring and registered with the activitiBeanRegistry! •  Use ʻactiviti:delegateExpressionʼ attribute to specify the delegate bean in the process deﬁnition:! <serviceTask id=“getMimetype" name=“Get Mimetype“ activiti:delegateExpression="${mimetypeGetter}" />

Service Tasks: Java Delegate Bean! •  Recommended to extend BaseJavaDelegate class! •  Recommend extending baseJavaDelegate bean! •  If the bean class extends BaseJavaDelegate and the Spring bean deﬁnition extends baseJavaDelegate, then the bean will automatically be registered with the activitiBeanRegistry and will have access to the serviceRegistry! <bean id=“mimetypeGetter" parent="baseJavaDelegate" class="org.alfresco.example.MimetypeGetter" />

Service Tasks: Java Delegate Bean!public class MimetypeGetter extends BaseJavaDelegate{ @Override public void execute(DelegateExecution execution) throws Exception { ScriptNode document = (ActivitiScriptNode) execution.getVariable("dcwkflw_document"); NodeRef nodeRef = document.getNodeRef(); ServiceRegistry serviceRegistry = getServiceRegistry(); FileFolderService fileService = serviceRegistry.getFileFolderService(); FileInfo file = fileService.getFileInfo(nodeRef); String mimetype = file.getContentData().getMimetype(); execution.setVariable("dcwkflw_mimetype“, mimetype); }}

Service Tasks: Arbitrary Expression! •  Execute any arbitrary expression! •  The expression may reference any bean deﬁned in Spring and registered with the activitiBeanRegistry! •  A process variable can be speciﬁed for the return value using the activiti:result attribute! <serviceTask id=”getMimetype” name="Get Mimetype" activiti:resultVariable="dcwkflw_mimetype" activiti:expression=“${mimetypeGetter.getMimetype(dcwkflow_document)}” />!

Listeners !

Listeners! •  Used to react to certain events during workﬂow execution! •  Two types: TaskLisener and ExecutionListener! •  Three ways to conﬁgure, as with ServiceTasks:! •  Listener Class:! <activiti:executionListener class="org.alfresco.example.MyExecutionListener" event=“start” />! •  Listener Bean:! <activiti:taskListener delegateExpression=“${myTaskListener}" event=“create" />! •  Arbitrary Expression <activiti:executionListener expression=“myPojo.myMethod(myVar)" event="start" />

Listeners: Execution Listener Events! •  Event: Execution (Workﬂow) starts or ends! <extensionElements> <activiti:executionListener class=“org.alfresco.example.ExecutionEventLogger" event=“start” /> </extensionElements>! •  Event: Activiti (Workﬂow Node) starts or ends! <userTask id=“theTask” name=“The Task” > <extensionElements> <activiti:executionListener delegateExpression=“${executionEventLogger}" event=“end” /> </extensionElements> </userTask>! •  Event: Sequence Flow (Transition) is taken! <sequenceFlow id=“theFlow” sourceRef=“theTask” targetRef=“theEnd” > <extensionElements> <activiti:executionListener expression=“${logger.info(execution.eventName)}" /> </ sequenceFlow > </userTask>

Listeners: Execution Listener Implementation! Execution Listener class or delegate bean must implement ExecutionListener interface:! public class ExecutionEventLogger implements ExecutionListener { private static final Log LOGGER = LogFactory.getLog(ExecutionEventLogger.class); @Override public void notify(DelegateExecution execution) throws Exception { String eventName = execution.getEventName(); LOGGER.info("Received event: " + eventName); } }!

Listeners: Task Listener Events! •  All Task Listeners deﬁned inside task elements:! <userTask id=“theTask” name=“The Task” > <extensionElements> <activiti:taskListener ... [Listener Details] ... /> </extensionElements> </userTask>! •  Event: assignment is called when a task is assigned to a user, usually called before create:! <activiti:taskListener event=“assignment” class=“org.alfresco.example.TaskEventLogger” /> •  Event: create is called when the task is created, after assignment:! <activiti:taskListener event=“create” delegateExpression=“${taskEventLogger}” /> •  Event: completed is called when the task is completed:! <activiti:taskListener event=“completed” expression=“${logger.info(task.eventName)}” />

Listeners: Task Listener Implementation! Task Listener class or delegate bean must implement TaskListener interface:! public class ExecutionEventLogger implements TaskListener { private static final Log LOGGER = LogFactory.getLog(ExecutionEventLogger.class); @Override public void notify(DelegateTask task) { String eventName = task.getEventName(); LOGGER.info("Received event: " + eventName); } }

Scripting!

Scripting! •  Scripting Lagnuage:! •  JavaScript! •  Activiti Implementations:! •  AlfrescoScriptDelegate! •  ScriptExecutionListener ! •  ScriptTaskListener!

Scripting: Scope Variables! •  person ScriptNode, the current user! •  userhome ScriptNode, the home space of the current user! •  execution DelegateExecution, the current execution.! •  task DelegateTask, the current task (ScriptTaskListener only)! •  cancelled boolean, was the execution cancelled (ScriptExecutionListener only)! •  deleted boolean, was the execution deleted (ScriptExecutionListener)!

Scripting: Execution Variables! •  All execution variables added to scope! •  Variable names translated from “prefix:suffix” to “prefix_suffix”! •  Associations and noderef properties converted to ScriptNodes! •  Use execution.setVariable(name, value) to modify variables! •  Check if a variable exists using:! if (typeof <variable name> != undefined)

Scripting: Examples! •  Copy a task variable to a process variable: execution.setVariable(dcwkflw_reviewOutcome, task.getVariable(dcwkflw_reviewOutcome)); •  Set a task property from a pocess variable if it exists: if (typeof bpm_workflowDueDate != undefined) task.dueDate = bpm_workflowDueDate; •  Apply an aspect ʻdcwkﬂw:publishedʼ to a document: var presentation = bpm_package.children[0]; // Get the presentation presentation.addAspect(dcwkflw:published); // Apply published aspect

Timers !

Timers! •  Timers are used to delay an event until a specified time/duration! •  Timers can be attached to three types of event:! •  startEvent: Starts the workflow! •  intermediateCatchEvent: Between nodes/events! •  boundaryEvent: Associated with a node (e.g. a userTask)! •  Three ways to set trigger time:! •  timeDate: Triggers at specified date/time! •  timeDuration: Triggers after specified delay duration! •  timeCycle: Triggers repeatedly with specified delay/interval! •  All dates/times/durations/intervals use ISO8601 format!

Timers: Start Event Date Example! •  Create a workﬂow which sends a Christmas Greeting  <startEvent id="start" > <timerEventDefinition> <timeDate>2011-12-25T12:05:00</timeDate> </timerEventDefinition> </startEvent> <sequenceFlow id=flow1 sourceRef=start targetRef=sendGreeting />

Timers: Intermediate Event Delay Example! •  Delay after some service task performs some asynchronous event to wait for the job to complete:! <sequenceFlow id=flow1 sourceRef=asyncJob targetRef=waitForJobToFinish />  <intermediateEvent id="waitForJobToFinish" > <timerEventDefinition> <timeDuration>PT1H30M</timeDate> </timerEventDefinition> </intermediateEvent> <sequenceFlow id=flow2 sourceRef=waitForJobToFinish targetRef=nextTask />

Timers: Repeating Boundary Event Example! •  Send a reminder email if a task isnʼt completed after 1 week. Repeat the email every day for 3 days:! <userTask id="theTask" >  <boundaryEvent id="repeatingNotification" cancelActivity="false" attachedToRef="theTask" /> <timerEventDefinition> <timeCycle>R3/P1W/P1D</timeDate> </timerEventDefinition> </boundaryEvent> <sequenceFlow id=flow1 sourceRef=repeatingNotification targetRef=sendEmail /> <serviceTask id="sendEmail" activiti:delegateExpression="${sendEmailDelegate}" />

Questions ?!

BPM-3 Advanced Workflow Deep Dive

by Alfresco Software on Nov 14, 2011

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BPM-3 Advanced Workflow Deep Dive — Presentation Transcript