Using Context and Command

[asrickard]

I've been trying to work out how to use context functions and the Command system, and need some suggestions/assistance.

I have a conversation-scoped Seam component "workflowProcessManager" in which I have a list of running processes which is refreshed when the user clicks a commandLink. In the same component I have a function to suspend a ProcessInstance.

@Name("workflowProcessManager")
@Scope(ScopeType.CONVERSATION)
public class WorkflowProcessManager {

private JbpmContext context;
private CommandServiceImpl csi;
private Boolean showActiveOnly = true;

@DataModel private List<ProcessDefinition> processDefinitions = new Vector<ProcessDefinition>(0);
@DataModelSelection("processDefinitions") @Out(required=false) private ProcessDefinition currentProcessDefinition;

@DataModel private List<ProcessInstance> runningProcesses = new Vector<ProcessInstance>(0);
@DataModelSelection("runningProcesses") @Out(required=false) private ProcessInstance currentRunningProcess;

public void init() {
 context = JbpmConfiguration.getInstance().createJbpmContext();
 populateProcessDefinitionList();
 csi = new CommandServiceImpl(context.getJbpmConfiguration());
}

public void showProcessesForProcessDefinition(ProcessDefinition pd) {
 GetProcessInstancesCommand gpic = new GetProcessInstancesCommand();

 if (this.showActiveOnly)
 gpic.setOnlyRunning(true);
 else
 gpic.setOnlyRunning(false);
 gpic.setProcessName(pd.getName());

 runningProcesses = (List<ProcessInstance>) csi.execute(gpic);
 System.out.println("ShowProcessesForProcessDefinition: runningProcesses contains " + runningProcesses.size() + " entries.");
}

public void suspendProcessInstance(Integer id) {
 System.out.println("Suspending process instance " + id);
 ProcessInstance pi = context.getProcessInstance(id);

 pi.suspend();

 System.out.println("Saving process instance " + id);
 context.save(pi);

 //Session session = context.getSession();
 //session.flush();

 if (pi.isSuspended()) System.out.println("Process instance is suspended = true");
 else System.out.println("Process instance is suspended = false");

 System.out.println("Refreshing processes for definition " + this.currentProcessDefinition.getName());
 showProcessesForProcessDefinition(this.currentProcessDefinition);

 for (ProcessInstance p : this.runningProcesses) {
 if (p.isSuspended()) System.out.println("Process instance " + p.getId() + " is suspended = true");
 else System.out.println("Process instance " + p.getId() + " is suspended = false");
 }
}

 public Boolean getShowActiveOnly() {
 return this.showActiveOnly;
 }
 public void setShowActiveOnly(Boolean showActiveOnly) {
 this.showActiveOnly = showActiveOnly;
 }

 @SuppressWarnings("unchecked")
 private void populateProcessDefinitionList() {
 processDefinitions = context.getGraphSession().findAllProcessDefinitions();
 }

}

And the guts of the page:

 <rich:panel>
 <f:facet name="header">Process List</f:facet>

 <h:panelGrid columns="2" columnClasses="twoColumnTopAligned">
 <h:panelGroup>
 <rich:dataTable value="#{processDefinitions}" var="processDefinition"
 onRowMouseOver="this.style.backgroundColor='#EAEAEA';this.style.cursor='pointer'"
 onRowMouseOut="this.style.backgroundColor='#{a4jSkin.tableBackgroundColor}'">
 <rich:column>
 <f:facet name="header">Process Name</f:facet>
 <h:outputText value="#{processDefinition.name}"/>
 </rich:column>

 <rich:column>
 <f:facet name="header">Description</f:facet>
 <h:outputText value="#{processDefinition.description}"/>
 </rich:column>

 <a:support event="onRowClick" reRender="instanceTable"
 action="#{workflowProcessManager.showProcessesForProcessDefinition(processDefinition)}">
 </a:support>
 </rich:dataTable>

 <s:decorate id="showActiveOnlyField" template="/layout/edit.xhtml">
 <ui:define name="label">Show only active processes</ui:define>
 <h:selectBooleanCheckbox id="showActiveOnly" value="#{workflowProcessManager.showActiveOnly}" />
 </s:decorate>
 </h:panelGroup>

 <rich:dataTable id="instanceTable" value="#{runningProcesses}" var="processInstance">
 <rich:column>
 <f:facet name="header">Id</f:facet>
 <h:outputText value="#{processInstance.id}"/>
 </rich:column>
 <rich:column>
 <f:facet name="header">Version</f:facet>
 <h:outputText value="#{processInstance.version}"/>
 </rich:column>

 <rich:column>
 <f:facet name="header">Status</f:facet>
 <h:outputText value="Finished" rendered="#{processInstance.hasEnded()}"/>
 <h:outputText value="Paused" rendered="#{processInstance.suspended}"/>
 <h:outputText value="Running" rendered="#{!(processInstance.hasEnded() or processInstance.suspended)}"/>
 </rich:column>

 <rich:column>
 <f:facet name="header">Current Node</f:facet>
 <h:outputText value="#{processInstance.rootToken.name}"/>
 </rich:column>

 <rich:column>
 <f:facet name="header">Actions</f:facet>
 <a:commandLink id="pauseProcessInstance"
 action="#{workflowProcessManager.suspendProcessInstance(processInstance.id)}"
 reRender="instanceTable"
 value="Pause">
 <s:conversationId />
 </a:commandLink>
 #{' '}
 <a:commandLink id="resumeProcessInstance"
 action="#{workflowProcessManager.resumeProcessInstance(processInstance.id)}"
 reRender="instanceTable"
 value="Restart">
 <s:conversationId />
 </a:commandLink>
 #{' '}
 <a:commandLink id="signalProcessInstances"
 action="#{workflowProcessManager.signalProcessInstance(processInstance.id)}"
 reRender="instanceTable"
 value="Signal">
 <s:conversationId />
 </a:commandLink>
 </rich:column>
 </rich:dataTable>

 </h:panelGrid>

 </rich:panel>

The problem I experience is that the list of running ProcessInstances is not refreshed correctly, unless I add in the hibernate session flush() (commented out in the code above).

The command service starts up a separate JbpmContext, which I believe is not seeing the results of the suspend() call, and so refreshes the .

Should I be looking for a problem somewhere in the configuration, and if so where? Or am I using the Jbpm features incorrectly somehow? Or do I need to manually flush like this?

Any pointers from more experienced people will be much appreciated...