Did you know SAP has one of the world's most powerful workflow engines built into its core basis system?SAP Workflow is a set of tools used to design, develop and implement workflows in SAP based on events that occur on various business objects. Based on an object oriented concept of Objects (BusinessObjects / Classes) SAP Workflow can fully automate allEnterprise workflowrequirements.SAP Workflow can be used when working with different Applications or Programs : Mobility , Webdynpro ABAP , CRM , SRM , BSP , SCM & many different modules.BASIC SAP GUI NAVIGATION Workflow terminology Use of workflow and workflow templates Difference between mail & workitem Basic Customizing settings in the SAP Business Workflow system Inboxes: Possible inboxes for work items Defining substitutes Processing work itemsAGENTS Agent Assignment Possible Agents , Responsible Agents , Excluded Agents Recipient Actual Agents Assigning Multiple Agents Per Work Item Deadline & Notification Agents Agent Assignment Using Organizational Structure The Basic Organizational Plan The Extended Organizational Plan Doing Without an Organizational Plan Agent Assignment Using TASK GroupBUILDING AND USING WORKFLOW Defining workflows using the Workflow Builder Binding Matrix Enhancing business objects with the Business Object Builder Defining business process steps: task definition Data definition and containers Dynamic agent determination at runtime Triggering workflows with events Triggering events in the system Deadline monitoring Workflow Wizards Options for ad-hoc processingWORKFLOW PROGRAMMING Business Object Builder: defining and implementing your own BOR objects Data flow and new containers Agent determination rules Rule Basics Testing & Simulating Rules Responsibility Rules with multiple criteria and Secondary priorities Agent Determination using SAP Organizational Data Function Modules as rules Programming exits at step and workflow level Event generation by programming Check function modules Receiver type function modules Receiver function modules Runtime system: Structure Performance AdministrationBUSINESS OBJECTS Creating Custom Business Objects Extending BO Types Via Delegation Debugging background methods in Workflow Business Object Components Adding Interface Creating Key Fields , Methods , Events Common Business Object Types Used with Many Workflow Scenarios SELFITEM WF_TASK SYSTEM USR01 , USER Methods: Synchronous methods Asynchronous methods Foreground Methods Background Methods Secondary Methods Before Methods After MethodsABAP CLASSES : OO-ABAP IN WORKFLOWPreqrequisite :( OO ABAP) Definition and implementation of ABAP-OO classes for use in the workflow Definition of attributes Definition of methods and error handling Definition of events Triggering ABAP-OO events Using ABAP-OO classes in workflow processes Difference between ABAP Classes & Business Objects UTILITY Classes in Workflow Creating Utility Class Workflow Interface IF_WORKFLOW : BI_PERSISTENT , BI_OBJECT Using Utility Class in a TASK Functional Methods Deadline monitoring using Utility Classes Business Classes in Workflow Difference between Utility & Business Classes Implementing& Usage of Local Persistent Object Reference Implementing ABAP class objects Event handling using class CL_SWF_EVT_EVENT Handling Exceptions using CX_BO, CX_BO_APPLICATION classesADVANCED WORKFLOW DESIGN TECHNIQUES Step Conditions Step Condition : Create Work Item Step Condition : Complete Work Item Step Condition : Completion Execution Implement Table Driven Dynamic Parallel Processing Implement a FORK Notify recipients Via EMAIL that a Deadline Missed Skip Work Item If Deadline Missed Scheduling background Job for Deadline Monitoring Parallel Processing Reusing Workflows as Sub Workflow Deadline Reactions : Standard Escalations , Modeled Escalations Modeled Deadline Escalations Binding Blocks & Local Workflow Ad-hoc Features & Review Work ItemEVENTS AND BUSINESS INTERFAECS Introduction to events Event linkage Table & Search For Events Evaluation and Maintenance of Type Linkages with Process Flow Triggering Events Start Conditions For workflows Terminating Event Workflow Header Events Parked Events , Event Queues Raising Events From Business Application Raising Events Via Classes Raising Events Via Status Changes Raising Events Via Change Documents Raising Events Via Message Control Raising Events Via HR Info type Raising Events Via BTE Raising Events Via calling a workflow API Raising Events Via Implicit Enhancement PointsWORKFLOW DIAGNOSTICS Diagnosis Logs Workflow Log Diagnosis Transaction Event Trace RFC Log Debugging WorkflowWORKFLOW ADMINISTRATION Error Resolution Techniques To Resolve Runtime Errors Basic Settings For Error Monitoring Finding & Fixing Work Items Diagnosis Of Workflows with Error Work Item Selection & Work Item Frequency Work Item Display : Standard & Technical View Resolving Agent Determination Errors Fixing work Item With No Agents Or Wrong Agents Preventing Agent Determination Problems From Recurring Resolve Buffering ErrorsPRACTICAL EXAMPLES DONE IN CLASS ROOM . First we learn handling Business Scenario with standard object Type for Business Partner Creation Business scenario handling terminating events, asynchronous method, building relationships between different object types, Binding Matrix, suppressing possible step outcomeswith custom object type. This one example will make sure any development in workflow you can complete easily without any trouble. This is a complete custom application Business Scenario with Standard Object type and delegation of subtype using deadline monitoring Macro creation & use at design time and runtime. Macro Reporting Real Time Workflow Project Scenario on Sales Pricing: This project topic Covers all real time based Development , Configuration , Negative & Positive TestingADVANCE TOPICS: Prerequisite :( OO ABAP & WEBDYNPRO ABAP) Workflow with UWL Web flow connector settings Webdynpro ABAP Application using different Workflow APIs Inbound & Outbound Plug configuration for UWL Net weaver Portal Integration And settings For UWL UWL validations Customizing the Workflow Template using XML generation in Portal Standard settings for workitems related UWL in backend. 9. Adv. Configuration using portal wizard 10. Workflow with BRF+

Using ABAP Object Oriented Coding in your Custom WorkflowSAP BusinessWorkflowwas built on an approximation of object orientated programming called the Business Object Repository or BOR. It uses object oriented techniques which allowed developers the ability to create copies of standard BOR objects, modify them and through inheritance allow them to be used in place of the standard.This was my comfort zone. I learned SAP and ABAP programming using BOR objects, creating attributes, coding methods, and developing workflows to meet my clients needs. As a workflow consultant I was special, as most of my ABAP friends felt intimidated by the concept of workflow and using Business Objects. However, as I enjoyed my specialized skill, I started doing a lot more ABAP development apart from workflow, and realized the new tools such as the ABAP workbench were much easier to use that the Business Object editor.When I used the Business Object Editor I felt I was going back towards my COBOL days of 72 column limitations. How free I felt being able to write code that continued right past my visible screen. Then came ABAP OO, and I started to realize my version of object oriented programming, was a far cry from where SAP was heading. I was an old dog! I enjoyed the ABAP workbench, but at the same time I intimidated by what seemed to me as a completely new programming language.ABAP OO and Workflow The Turning PointA couple of years ago, I was working with a Workflow consultant who I did not know, and as soon as he was done with his first workflow I decided I would take a peak to see what level of developer was on our teamWell, I opened the workflow, went to the triggering events, and saw an ABAP class rather than a BOR as the triggering event. I drilled into the class, saw all of the methods, attributes, types, events, and realized all of his tasks used this class as well. As I looked at the workflow I was immediately impressed. While I had been relying on my use and knowledge of BOR, this Workflow consulting had taken the next step and was using ABAP OO for everything. At that point I decided I needed to figure out how to use this new technique, and force myself to learn using ABAP OO in this way.Why Use ABAP OO for SAP Business Workflow?Now that I had a mission, I had to figure out what the advantages of using ABAP OO had over BOR. As I started investigating, reading blogs, workflow books, and looking at our current SAP system, I started to find that SAP was using ABAP classes for many of their own workflow processes, and most of their code base was now ABAP OO.I kept on seeing was that the code was easily maintained by ABAP programmers without workflow knowledge, A huge advantage! I had to think about this one. My lively hood depends on the fact that clients need workflow specialist. But as I continued pondering this dilemma, I also came to the conclusion that if I did not start to learn this, I would not be able to maintain the newer workflows that utilize ABAP OO. In addition, if I could master ABAP OO I would be able to broaden my skill set and my own marketability.I have worked with various customers and clients over the past decade and I have noticed that most of the workflows that I have developed arent as much about delivering decision tasks to the correct people, but rather automating a complicated set of procedures that cross various functional areas of responsibility. This is where ABAP OO can really help. Complex code used for common business processes is much easier to access and reuse with classes and methods instead of the traditional BOR Editor.Now please do not misunderstand me. There is still a need for BOR and the use of it in SAP Business Workflow. A lot of business processes have been built on this foundation, and to replace them with ABAP OO would not make fiscal sense, as the cost of developing, testing, and the disruption to current processes would be too great. So when a new requirement came along which did not have a current workflow I could build upon, I took the plunge and built it using ABAP OO.Now that you can have a good understanding of how SAP Business Workflow can benefit from using ABAP OO, the next blog will get into details on how make a custom class usable in workflow as well as how to create events and start workflows using ABAP OO.Using ABAP Object Oriented Coding in your Custom WorkflowIn the first part of this blog regarding the use of ABAP OO with SAP Workflow, I explained some of the benefits of using ABAP OO with your custom workflows. In this part I will go into more detail about creating an ABAP OO class and using it within a workflow. This blog does not go into great detail about ABAP OO programming so learning some basics via other blogs or books is helpful.Creating a class that can be used by workflow is a little more time consuming than creating a copy of a standard SAP Business Object and delegating your new object, but once you have done it a few times it is rather simple and allows you to utilize ABAP OO.Using SE24 I created a classZCLZZ_WF_DEMO_CLASSwhich I will use in this example to represent a vendor. In order for workflow to be able to use this class you need to add the interfaceIF_WORKFLOW. The important part of this interface is called theLocal Persistent Object Reference, which is used to convert the workflow object reference into the specific instance of the ABAP Class, as well as the reciprocal. This transformation is handled in the two interfaces included withIF_WORKFLOW;BI_PERSISTENTandBI_OBJECT.The methodsBI_PERSISTENT~FIND_BY_LPORwill convert the current object reference used by workflow into instance of the ABAP Class. TheBI_PERSITENT~LPORmethod will convert the ABAP instance into the workflow instance. While this communication was handled behind the scenes with BOR objects and workflow, a little bit of coding on your part is now needed.Once the interface has been added, you need to open each method inherited fromIF_WORKFLOWand activate the empty source code. As mentioned previously, the methodsFIND_BY_LPORandLPORare the ones we need to concentrate on.Below is the code that I added to theCONSTRUCTOR,FIND_BY_LPORandLPORmethods, as well as theClass Attributesrequired.Workflow Class Attributes:

Workflow Class Constructor:

Workflow Class Method FIND_BY_LPOR:

Workflow Class Method LPOR:

Next, I created a simple methodDISPLAY_VENDORwhich we can use in a task in our workflow for the user to execute with an exporting parameter of RETURN to match our BAPI call

The next step is to create an event which we will use to start our new workflow, as well as a method to raise the event. On the events tab I created an eventSTART_WF. I did not include any event parameters but it is as simple as clicking on thePARAMETERSbutton and adding them if you need too.

Next I created a method that would raise our new event. The code for this is a little different than the function module calls we are used to using likeSWE_EVENT_CREATEorSAP_WAPI_CREATE_EVENT. Instead you use a call to classCL_SWF_EVT_EVENTmethod RAISE or RAISE_IN_UPDATE_TASK.If your event has parameters in an event container, call the methodGET_EVENT_CONTAINERto return the definition from the event, and/or SET_EVENT_CONTAINERto populate the event container parameters.

OK We are ready to use our new class in a Workflow!!I have built a simple workflow that will start from our event defined in our ABAP OO class, as well as call a task using ourDISPLAY_VENDORmethod.From the workflow builder screen (Part ofWorkflow DevelopmentTools) click on the define workflow Triggering Events tab, andrather than selecting BOR Object Type, instead select ABAP Class as the object category.Enter the class and the event, and bindings, binding the event object to a workflow container defined as your class, and finallyactivate the event.

Next, create a task that calls the method within the class. A trick you need to know, is that after you save the task,you need to check the Synchronous object method box

Once you have inserted the task into your workflow and activated it you can test the process from SE24 and executing the methodSTART_WF. If everything was done correctly you will see your workflow was started and by executing the work item in the Workflow INBOX, the vendor is displayed.This is just a very simple example, but as you can see using ABAP OO opens up a whole new dimension to workflow processes. As I stated in the first part of this blog, most of the workflows that I have done in recent years arent designed to deliver the work to the right people at the right time, but rather to automate as many processes as possible in an effort to minimize segregation of duty issues. With ABAP OO it is much easier to incorporate complex code and access standard SAP logic.In the next part of this blog I will go into more details about work items using ABAP OO, how to create the equivalent of BOR attributes within the class, as well as some tips and tricks that I have learned and continue to learn as I expand my use and knowledge of SAP Workflow using ABAP OO.ABAP Object Oriented Coding and Workflow BOR IntegrationIn the first part of this blog regarding the use of ABAP OO with SAPWorkflow, I explained how to use an ABAP OO class to start a workflow as well as call one of the methods in the class from a work item. In this final installment I will demonstrate how to instantiate an ABAP OO class from workflow, the use of functional methods, and finally some tips I have learned while developing custom workflows using ABAP OO.Since BOR is still a common repository for a number of objects it is likely that you have a workflow that is triggered by a traditional BOR event. But for our demonstration purposes you want to use a class to handle many of the functions and rather than add these methods to the BOR. You want to utilize an ABAP OO class.When the workflow starts you have an instance of the BOR object which is defined by the key fields that were instantiated and passed during the normal event creation. Now you want to instantiate the class which you are going to utilize. Leveraging the class we developed in the previous blogs, create a method that has in input parameter as which is the key to the class, and an export parameter that is a type reference to your class. The method CREATE_INSTANCE is defined as static and public.

Create a New Workflow TaskCreate a task using theWorkflow DevelopmentTools which calls the new method, and make sure to indicate that it is Synchronous object method.

Next, include this task in a custom workflow. For this demonstration I created a workflow that is started from BOR LFA1 event CREATED. Test the workflow using SWUS passing in the key to LFA1 which is the Vendor Number. View the workflow log and container to see that you now have an instance of the ABAP OO class which will allow you to reference the class methods and attributes.

Within a BOR object you can have different types of attributes, so that once the object is instantiated the value is calculated.To do the same in a class, you can create an attribute that is populated from a method that is executed from the constructor method. I created a simple attribute VENDOR_NAME as a read only attribute. I then created a method named READ_ATTRIBUTES which will read the name of the vendor and populate the attribute. I placed the execution of this method into the constructor, and when the class is instantiated the VENDOR_NAME is populated and is available to workflow.

An alternative to an attribute would be a functional method. These would be an approximate equivalent tovirtual attributesfor a BOR object. The added value here is that you can pass in parameters to use during the method, and you can call these methods again and again when you need to rather than only executing the code when the class is instantiated.I created a method to get the list of user ids assigned to a particular work center. I then created a simple task that passed in the value of the work center and returned the users assigned.

Experience Matters.. Tips &TricksLastly I wanted to share an issue that I ran into while using ABAP OO with a new custom workflow that I had created. When I first learned workflow I was taught to develop the method first, then a task that calls the method and finally insert the task into the workflow. This would allow the system to automatically generate the container elements required at each step so that I only defined them once at the method level. I still use this practice today, but while developing my first ABAP OO based workflow I had used a method from a class where the return parameter was typed using begin of instead of a data dictionary type.

So when I went to create the task to call the new method it automatically created the data element with a definition as below.

This worked in development and tested just fine. The issue was when we transported the workflow and class to the QA environment, the transport failed with a return code of 12. After several attempts to fix it, I finally discovered that the workflow was unable to generate because it could not find the type CLASS=ZCLZZ_WF_DEMO_CLASSTYP which was truncated. In order to fix it I had to create a structure that matched the definition to use as the type and it transported successfully.Final thoughtsUsing ABAP OO with my workflows has been a learning experience, which has allowed me to enhance my knowledge of ABAP OO as well as workflow as more SAP developed workflows go down this route. As I stated in the first part of this series, I have been comfortable using BOR for many years, and had to step outside my comfort zone in order to try using ABAP OO. It was not an easy first step, but as with any new skill, the more you do it the easier and better you become.

ABAP Classes in WorkflowBy Anwesha Bhattacharya , Capgemini India fromLink1.ABAP Classes and Business Workflow:We can useABAP classesin the definition and runtime components ofSAP WebFlow Enginein the same way as object types defined in the Business object Repository (BOR).Before proceeding further we need to know where to create and maintainABAP ClassesandABAP Interfaces.2.What is Class Builder and its purpose?TheClass Builderallows us to create and maintain global ABAP classes and interfaces. Both of theseobject types, like global data types, are defined in theABAP Repository, thus composing a central class library. Together, they form a central class library and are visible throughout the system. We can display existing classes and interfaces in the class library using theClass Browser.We can define local classes as well as global classes. They are defined locally in programs, function groups or as auxiliary classes of global classes of the class pools. Local classes are only visible within the defining module.ABAP classes are processed using the Class Builder.3.How to reach Class Builder?To reach theinitial screenof the Class Builder, chooseDevelopmentClass Builderfrom the initial screen of the ABAP Workbenchor enter transaction codeSE24.

4.How does it integrate?The Class Builder allows us to create Web development objects within the ABAP Workbench. We can use the Class Browser to display and maintain existing global object types from the class library. The diagram below illustrates the architecture of the Class Builder and the relationships between its components (including the Class Browser)

From here, we can either display the contents of the class library or edit a class using the Class Editor.Once we have defined an object type, we can implement its methods. From the initial screen or the Class Editor, we can also access the Class Builders test environment. We can define the object types immediately after implementing the method in the ABAP Editor. It is also possible to access the test environment from the initial screen or Class Editor.5.How to use the Class Builder?Use the Class Builder to: Display an overview (in the Class Browser) of global object types and their relationships. Maintain existing global classes or interfaces. Create new global classes and interfaces. Implement inheritance between global classes. Create compound interfaces. Create and specify the attributes, methods, and events of global classes and interfaces. Define internal types in classes. Implement methods. Redefine methods. Maintain local auxiliary classes. Test classes or interfaces in a simulated runtime environment.6.What are the constraints?We cannot define object types on the basis of graphical object modeling.7.Note before creatingglobal classes and interfaces:Global classes and interfaces that we create in the Class Builder are stored in the class library and administered by the R/3 Repository: they therefore have the same namespace as all other Repository objects. It is therefore necessary to have naming conventions for object types and their components and to use them uniformly within program development.8.Naming Conventions in ABAP Objects:The following naming convention has been conceived for use within theSAP namespace. If we do not observe the naming conventions for object types (classes and interfaces), conflicts will occur when the system creates persistent classes, since it will be unable to generate the necessary co-classes.9.Conventions for Object Types:Class in the class libraryCL_

Interfaces in the class libraryIF_

Local classes in programs(recommendation)LCL_

Local interfaces in programs(recommendation)LIF_

10.Conventions for Components:Method name

Events

Local type definitions within a class(recommendation)TY_

Data definitions (variables)

Data definitions (constants)(recommendation)CO_

11.Local Conventions within Methods:For parameters:IMPORTING parametersIM_

EXPORTING parametersEX_

CHANGING parametersCH_

RESULTRE_

12.Using ABAP Classes in Workflow:Within theSAP WebFlow Engine wecan use ABAP classes that support theIF_WORKFLOWinterface. Classes that have implemented theIF_WORKFLOWinterface are recognized as workflow-enabled in the Class Builder.13.How to create ABAP Classes that support IF_WORKFLOW interface? Go to transactionSE24and create a customized class.

Next the pop up appears where we need to mention the detail as follows: Save it and the class is created. Now the class is to implement IF_WORKFLOW interface. For this go to thetab and declare the IF_WORKFLOW as the interface there and press Enter; two sub-interfaces appear:BI_OBJECTandBI_PERSISTENT. Save the Class.

The ZCL_TEST class now contains the existing methods of IF_WORKFLOW interface.14.Lights on Key Attributes and Attributes:The key attributes are used to define the object key. There can also be other defined attributes other than key attributes. The SAP WebFlow Engine can access all public attributes of a class.Key Attributes:In the Class Builder there is an additional columnKey Attributeson thetab page as shown below:

We need tocheckthis box when we are defining any attribute as the Key Attribute.All key fields must be character-type fields (elementary types:CHAR, NUMC) and have a defined length. The maximum length allowed for all key fields is 32 characters. The length of the key field for the persistent display is 32 characters.In the case of persistent ABAP objects we can use the GUID, which is generated automatically by the object manager when an instance is created.Attributes:In addition to all the other data types that the Class Builder supports, we can also define attributes with reference to an object from the Business Object Repository (BOR). To do this, we have to use the structureSWOTOBJIDas the data type. The BOR object is determined using the corresponding value.To assign a BOR object instance to an attribute we need to use the corresponding BOR macros. Normally, this is implemented within theCONSTRUCTORof a class.To use the BOR macros in a class, twoINCLUDESmust be included.Include contains the local typesInclude contains the BOR macrosAn example to show how to define Attributes and Key Attributes:

15.Why IF_WORKFLOW Interface?TheIF_WORKFLOWinterface is necessary when using an ABAP class within the SAP WebFlow Engine. The interface contains methods that allow the object to be used within the SAP WebFlow Engine.The SAP WebFlow Engine handles all objects generically. Objects have to be saved in the event of a context change. Therefore, it is necessary to convert object references in such a way that they can be saved persistently. Conversely, we have to be able to generate the corresponding instance of an ABAP class from the persistently saved key.There are also a number of SAP WebFlow Engine components, for example, theWorkflow Logthat can display objects. In this case the object has to provide corresponding functions.TheIF_WORKFLOWinterface puts a logical parenthesis round theBI_PERSISTENT(instance management) andBI_OBJECT(object behavior) interfaces. TheIF_WORKFLOWinterface contains the following methods:BI_PERSISTENT~FIND_BY_LPORBI_PERSISTENT~LPORBI_PERSISTENT~REFRESHBI_OBJECT~DEFAULT_ATTRIBUTE_VALUEBI_OBJECT~EXECUTE_DEFAULT_METHODBI_OBJECT~RELEASEA class that implements theIF_WORKFLOWinterface can be used in any workflow. The class is automatically released for use in workflows when the interface is implemented. Therefore, we can only make compatible changes to a class after implementation (we cannot delete attributes, change types or delete methods). There is no where-used list to show which workflows the class is used in.Internal classes of an application should not implement theIF_WORKFLOWinterface, since this could mean that each method of the class is used in the workflow. Therefore, we should encapsulate the workflow functions in another class that calls the selected methods of the internal class.Each method of the IF_WORKFLOW Interface as mentioned earlier has its distinct functionality, which is discussed below.16.BI_PERSISTENT~FIND_BY_LPOR Method:If we want to convert a persistent saved display of an object into an instance of the corresponding ABAP class, SAP Webflow Engine calls theBI_PERSISTENT~FIND_BY_LPORmethod.Features:The method parameter LPOR is the persistent object reference and is of SIBFLPOR structure type. A reference of BI_PERSISTENT type is returned.The following table shows the components of theSIBFLPORstructure:FieldDescription

CATIDDescribes the object type ( CL for ABAP classes)

TYPEIDABAP class name

INSTIDObject key. The key is limited to 32 characters.

We can implement this method in several ways. In the case of persistent classes we can create the ABAP object instance using the generated classes. In the case of individual persistence management we have to implement the individual actions (such as creating an instance, performing an existence check, entering public attributes, and so on) manually within the class.Instance management takes place automatically in the case of persistent classes. In the case of individual persistence management we also have to carry out instance management by class. The SAP WebFlow Engine does not provide any instance management. We must therefore implement our own instance management in the case of individual persistence management.The FIND_BY_LPOR method should always return the same instance if the following problems are to be avoided: Inconsistency in the data display Instance data being overwritten by another instance Locking conflictsThere is an implementation example in the CL_SWF_FORMABSENC demo class.

17.BI_PERSISTENT~LPOR Method:TheBI_PERSISTENT~LPORmethod is the counterpart to theBI_PERSISTENT~FIND_BY_LPORmethod. It provides the persistent display for an existing instance of an ABAP object.Features:The method returns the persistent display of an object reference as aSIBFLPORtype structure as described earlier.There is a close relationship between theBI_PERSISTENT~FIND_BY_LPORmethod and theBI_PERSISTENT~LPORmethod. If we call theBI_PERSISTENT~FIND_BY_LPORmethod first and then theBI_PERSISTENT~LPORmethod, theBI_PERSISTENT~LPORmethod must return the same value as was previously used to call theBI_PERSISTENT~FIND_BY_LPORmethod.There are also several ways of implementing this method in this case. There is an implementation example in theCL_SWF_FORMABSENCdemo class.

18.BI_PERSISTENT~REFRESH Method:SAP WebFlow Engine calls theBI_PERSISTENT~REFRESHmethod when the system has to ensure that all values of an object are valid or that they agree exactly with the persistent display of the object.Features:The method implementation depends on the internal organization of the class. We can check the object instance data in the database, if necessary.If we do not need the method in our class, then we need only to carry out a dummy implementation (without further coding) to avoid program errors when the system calls the method.There is an implementation example in theCL_SWF_FORMABSENCdemo class.

19.BI_OBJECT~DEFAULT_ATTRIBUTE_VALUE Method:TheBI_OBJECT~DEFAULT_ATTRIBUTE_VALUEmethod returns the display name of the object.Features:We can display references to process objects or process step objects at different positions within theSAP WebFlow Engine(for example, inBusiness Workplace and in Workflow Log). The object key is normally displayed here. If, for example, we want to display a descriptive text instead, the BI_OBJECT~DEFAULT_ATTRIBUTE_VALUE method has to return the corresponding value.If the method does not contain implementation or does not return a value, the object key is displayed.If we do not need the method in our class, then we need only to carry out a dummy implementation (without further coding) to avoid program errors when the system calls the method.There is an implementation example in the CL_SWF_FORMABSENC demo class.

20.BI_OBJECT~EXECUTE_DEFAULT_METHOD Method:TheBI_OBJECT~EXECUTE_DEFAULT_METHODmethod is the standard method for the object. This method is executed when, for example, we call the object inBusiness Workplace.Features:We can display process objects or process step objects at different positions within theSAP WebFlow Engine(for example, inBusiness Workplace and in Workflow Log). TheSAP WebFlow Enginecalls the BI_OBJECT~EXECUTE_DEFAULT_METHOD method.If we do not need the method in our class, then we need only to carry out a dummy implementation (without further coding) to avoid program errors when the system calls the method.There is an implementation example in theCL_SWF_FORMABSENCdemo class.

21.BI_OBJECT~RELEASE Method:The system indicates that the reference to the instance is no longer needed by using theBI_OBJECT~RELEASEmethod. This means we can delete the reference from instance management. Once the last reference has been deleted from instance management, theGARBAGE COLLECTORcan release the corresponding memory area.Features:If we do not need the method in our class, then we need only to carry out a dummy implementation (without further coding) to avoid program errors when the system calls the method.There is an implementation example in theCL_SWF_FORMABSENCdemo class.22.How to use ABAP Classes in Process Steps of Business Workflow?In process steps we can use methods and attributes of ABAP classes in the same way as methods and attributes ofBusiness Object Repository (BOR) objects. We can call these methods in the process context.Features:While using the ABAP Classes in the Process Steps the methods may contain dialogs, they can be synchronous or asynchronous; they may appear in the workflow log, and so on.In general, we can use any method that is implemented as a public method. The method can be implemented in the class itself, in one of the super classes of the class, or by way of an interface.The maximum permitted length for methods that are implemented by way of an interface, for exampleIF_WORKFLOW~FIND_BY_LPOR,is 30 characters. If the method name is too long, we can choose a shorter name for the method by defining an alias. If the method is implemented in the class or in a super class, the name of the method cannot be longer than 30 characters, so this limitation does not apply.Parameters:We can assign values from the workflow container to the method parameters. Conversely, export parameters can be entered as workflow container values. The following overview shows how the individual types can be used as parameters:Simple types (string, integer, and so on)Data Dictionary types (structures, tables, complex types)References to objects from the Business Object RepositoryReferences to ABAP classes (supporting the IF_WORKFLOW interface)We can transfer method parameters that represent a persistent object (IF_WORKFLOW orBOR Object) in the following ways:ABAP classes (with IF_WORKFLOW interface)TYPE SIBFLPORBObject is transferred using the persistent displayTYPE REF TO Object is transferred as object referenceBOR objectsTYPE SIBFLPORBObject is transferred using the persistent displayTYPE SWOTOBJIDObject is transferred using the persistent display; this display is only valid for BOR objectsTYPE SWC_OBJECTObject is transferred as object referenceExceptions:TheSAP WebFlow Enginecan deal with exceptions that are triggered by the methods. It differentiates between application exceptions and temporary exceptions. The two exception categories are differentiated by the exception in the class hierarchy or by naming conventions. In the case of a temporary exception, theSAP WebFlow Engineattempts to execute the method again. In the case of a permanent error the status for the workflow is set to error.Class-Based Exceptions:To create a temporary exception, we can use, for example, theCX_BO_TEMPORARYclass or a corresponding subclass. It can be helpful to trigger an exception for dialog methods when the user cancels the dialog. Here, for example, we could trigger theCX_BO_ACTION_CANCELEDexception (subclass of theCX_BO_TEMPORARYclass).Exceptions Not Based on Class:We can also trigger exceptions not based on class. The SAP WebFlow Engine can differentiate between the two exception categories (temporary and permanent) by the name. If the exception begins with TMP or TEMP, it is a temporary exception; otherwise it is a permanent exception.

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