Package de.xima.fc.interfaces.workflow.mixin

Interface IExecutingLikeExceptionHandlerNode<TData>

Type Parameters:

TData - Type of the node's properties model.

All Superinterfaces:

ICustomParametersUpdateable, IElementHandler<TData,WorkflowNode>, IExecutionResultDescriptor, INodeHandler<TData>, IRefinedExecutionResultDescriptor<TData>, IResourceBundleLocator, IWorkflowElementTypeProviding, IWorkflowNodeFlowAnalyzer<TData>, IWorkflowNodeTypeProviding

All Known Implementing Classes:

FcExperimentHandler

public interface IExecutingLikeExceptionHandlerNode<TData>
extends INodeHandler<TData>

Mixin with the implementation of createFlowGraph for node handlers that attempt to execute its body child node, and run another child if the child completed abruptly by throwing an exception, optionally always running a finalizer block at the end, such as a try-catch(-finally) block.

The semantics for the finalizer block are as specified by the Java language spec. In particular, when the finalizer completes abruptly in any manner (such as by throwing an exception or by issuing a control transfer or return statement), that abrupt completion result always replaces the completion result of the try-catch block. For example, the code below returns 10 and does not throw an exception.

 int foobar() throws Exception {
   var i = 0;
   loop: while (++i < 10) {
     try {
       throw new Error("42");
     }
     finally {
       continue loop;
     }
   }
   return i;
 }
 

Since:

7.0.0

Author:

XIMA MEDIA GmbH

Field Summary

Fields inherited from interface de.xima.fc.interfaces.workflow.elements.IElementHandler

CURRENT_HANDLER_VERSION

Method Summary

Modifier and Type	Method	Description
default <TElement extends IWorkflowNodeTypeProviding & IActiveFlagProviding> IFlowGraphEndPoints	createFlowGraph(ICreateFlowGraphParams<TData,TElement> params)	This method is used to create the flow graph that represents the control flow of a workflow task, and to determine the end points of the node when executed.
int	getBodyChildIndex()
int	getFinalizerChildIndex()
int	getHandlerChildIndex()

Methods inherited from interface de.xima.fc.interfaces.workflow.ICustomParametersUpdateable

updateCustomParams

Methods inherited from interface de.xima.fc.interfaces.workflow.elements.IElementHandler

extractDescription, extractName, extractSearchTerms, getCascadingStyleSheet, getCascadingStyleSheet, getDataModelClass, getDisplayLabel, getElementSummaryModel, getElementSummaryXhtml, getFastJsonConverter, getFilterCriteriaForEntities, getHelpPageLocation, getJavaScript, getJavaScript, getPropertiesViewXhtml, getResourceBundle, getVersion, isAvailable, isHasUserVisibleName, readEntityReferences, readPlaceholders, validateGlobal, validateLocal, writeEntityReferences, writePlaceholders

Methods inherited from interface de.xima.fc.interfaces.workflow.execution.IExecutionResultDescriptor

getAlwaysValueDescriptor, getAttachmentValueDescriptor, getCurrentAttachmentValueDescriptor, getCurrentFileValueDescriptor, getCurrentValueDescriptor, getErrorValueDescriptor, getFileValueDescriptor, getSoftErrorValueDescriptor, getSuccessValueDescriptor

Methods inherited from interface de.xima.fc.interfaces.workflow.nodes.INodeHandler

execute, getLocalizedTypeName, getNodePrototypes, getPropertiesBeanClass, getRelatedNodeTypes, getSupportedControlTransferTypes, isCreateProtocolEntryAfterExecution, isCreateProtocolEntryAfterExecution, isReplacePlaceholderBeforeExecution

Methods inherited from interface de.xima.fc.interfaces.workflow.execution.IRefinedExecutionResultDescriptor

getAlwaysValueDescriptor, getAttachmentValueDescriptor, getCurrentAttachmentValueDescriptor, getCurrentFileValueDescriptor, getCurrentValueDescriptor, getErrorValueDescriptor, getFileValueDescriptor, getSoftErrorValueDescriptor, getSuccessValueDescriptor

Methods inherited from interface de.xima.fc.interfaces.workflow.IWorkflowElementTypeProviding

getType

Method Detail

createFlowGraph

default <TElement extends IWorkflowNodeTypeProviding & IActiveFlagProviding> IFlowGraphEndPoints createFlowGraph(ICreateFlowGraphParams<TData,TElement> params)
                                                                                                          throws WorkflowAnalysisException

Description copied from interface: IWorkflowNodeFlowAnalyzer

This method is used to create the flow graph that represents the control flow of a workflow task, and to determine the end points of the node when executed. A flow graph constructed by the workflow engine and used for the purpose of deriving statements about the runtime behavior of the program represented by a workflow task with a root node.

See below for details on how to construct a flow graph. However, note that unless you are creating a new custom flow control node, you should use on of the existing mixins that matches the type of node you are creating:

• IExecutingLikeActionNode for normal business actions that execute some logic and have no children.
• IExecutingLikeBinarySelectionNode for custom conditions that behave like an if-else statement.
• IExecutingLikeControlTransferNode for custom control transfer actions such as break or continue statements (you will rarely need this).
• IExecutingLikeExceptionHandlerNode for custom error handlers that behave like a try-catch-finally statement.
• IExecutingLikeMultiSwitchNode for custom conditions that behave like switch-case-default statement.
• IExecutingLikePostTestLoopNode for custom loops that behave like a do-while-loop.
• IExecutingLikePreTestLoopNode for custom loops that behave like a while-loop.
• IExecutingLikeReturningActionNode for custom end points that can both throw an exception and end a processing chain by returning.
• IExecutingLikeReturnNode for custom end points that always return and never throw an exception.
• IExecutingLikeSequenceNode for custom block statements that never throw and execute their children in order (you will rarely need this).
• IExecutingLikeThrowNode for custom throw statements that can never complete normally and always throw an error.

The flow graph is a directed graph. Each node in the control flow graph is either

• a real node that corresponds to a WorkflowNode; or
• a virtual node owned and created by a real node

The graph has an edge from node1 to node2 if it is possible that node1 transfers control directly to node2; i.e any code path exists where node2 is executed directly after node1. Each edge also has a type, see FlowGraphConnectionType. Virtual nodes are often used to model complex control transfers involving conversion between completion types, such as try-finally blocks.

Regarding end points, see the documentation of Normal, Throwing, and ControlTransfer for more details.

This method is not pure and must have side-effects. It is responsible for

1. calling createFlowGraph (or one of its variants) on all of its children (if applicable);
2. calling connect (or one of its variants); and
3. returning the set of normal and throwing end points of the node.

This method must return the set of all nodes (including the children, grand-children etc. of this node) that represent the normal and throwing end points when the node is executed. These throwing end points are used for connecting this node to other siblings and parents. See the documentation of the sub classes of FlowGraphEndPoint for more details.

Specified by:

createFlowGraph in interface IWorkflowNodeFlowAnalyzer<TData>

Type Parameters:

TElement - The type of the node elements on which the analysis is performed. This type may be different depending on whether the analysis is performed on the backend data model WorkflowNode or the frontend view model.

Parameters:

params - The node to analyze and the current analysis context.

Returns:

The set of all end points of the given node. Use ICreateFlowGraphContext#endPoints and its variants to create this return value. See the documentation of getNormalEndPoints and getThrowingEndPoints for more details.

Throws:

WorkflowAnalysisException - May be thrown when an unhandled exception occurred during the analysis. If this exception is thrown, the entire analysis is cancelled and the exception is propagated up. You should only throw this exception yourself if encountering an illegal state that would render the analysis invalid.

getBodyChildIndex

int getBodyChildIndex()

Returns:

Index of the child representing the block ("try").

getFinalizerChildIndex

int getFinalizerChildIndex()

Returns:

Index of the child representing the finalizer ("finally").

getHandlerChildIndex

int getHandlerChildIndex()

Returns:

Index of the child representing the handler ("catch").