Custom BPM Applications(InitiableTasks) ADF TaskFlow

In a previous post, we show how to access the initiable tasks in a main method of a simple Java class. In line with, this post demonstrates how to get the task's URL and launch the corresponding generated BPM task details form in an ADF application.


The following are the key methods and artifacts:

• getTaskDisplayURL() - this method retrieves from a task object, the URL defined in the runtime Human Task configuration of a specific deployed composite, which can be found in Enterprise Manager. The URL is automatically set when you deploy a web app that contains BPM task forms with the configuration - "hwtaskflow.xml" that contains our task definition.
• getTaskFlowDefinitionId() - this method returns a TaskFlowId object from the lengthy URL returned by the getTaskDisplayURL() method above.
• initiateTask() - this method that returns a string is used as action attribute in the page fragment. It invokes both methods above then returns a "callTaskDetail" which launches a declarative popup.
• The declarative pop-up, "modal-dialog-task-flow", is a simple task flow that we reused from the BPM Worklist components library. It doesn't do much but invoke a remote task flow. We could create our own if necessary.
• wf_client_config.xml - We add this config file to remove from our code the connection details. To get a BPMServiceClientFactory instance, we just passed null parameters as follows:
  factory = BPMServiceClientFactory.getInstance(null, null, null);
  
• Configure ADF Security - so we don't need to pass username and password when getting a BPMContext.

Below is the the backing bean that support our page fragment.

package soadev.bpm.web.backing;

import java.net.URLDecoder;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;

import oracle.adf.controller.TaskFlowId;

import oracle.bpel.services.bpm.common.IBPMContext;
import oracle.bpel.services.workflow.task.model.Task;
import oracle.bpel.services.workflow.worklist.api.util.WorklistUtil;
import oracle.bpel.services.workflow.worklist.servlet.Constants;

import oracle.bpm.client.BPMServiceClientFactory;
import oracle.bpm.services.client.IBPMServiceClient;
import oracle.bpm.services.processmetadata.IProcessMetadataService;
import oracle.bpm.services.processmetadata.ProcessMetadataSummary;

import org.apache.myfaces.trinidad.context.RequestContext;

import soadev.view.utils.JSFUtils;


public class InitiableTaskListForm {
    private IBPMContext bpmContext;
    private ProcessMetadataSummary process;
    private BPMServiceClientFactory factory;

    public InitiableTaskListForm() {
        factory = BPMServiceClientFactory.getInstance(null, null, null);
    }
    public List<ProcessMetadataSummary> getInitiatiableTasks() {
        try {
            // get the process metadata service
            IProcessMetadataService pms =
                factory.getBPMServiceClient().getProcessMetadataService();
            // get the list of initiatable proceses
            return pms.getInitiatableProcesses(getIBPMContext());
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
    
    public String initiateTask() throws Exception {
        Task task = initiateTask(process.getCompositeDN()+ "/" + process.getProcessName());
        String detailsUrl = getTaskDisplayURL(task);
        getPageFlowScope().put("remoteUserTaskUrl", detailsUrl);
        getPageFlowScope().put("remoteTaskDefId", getTaskFlowDefinitionId(detailsUrl));
        return "callTaskDetail";
    }


    private Map<String, Object> getPageFlowScope() {
        return RequestContext.getCurrentInstance().getPageFlowScope();
    }

    private Task initiateTask(String compositeDN) throws Exception {
        IBPMServiceClient client = factory.getBPMServiceClient();
        return client.getInstanceManagementService().createProcessInstanceTask(getIBPMContext(),
                                                                               compositeDN);
    }

    private String getTaskDisplayURL(Task task) throws Exception {
        Map parameters = new HashMap();
        parameters.put(Constants.BPM_WORKLIST_TASK_ID,
                       task.getSystemAttributes().getTaskId());
        parameters.put(Constants.BPM_WORKLIST_CONTEXT,
                       getIBPMContext().getToken());
        String url =
            WorklistUtil.getTaskDisplayURL(factory.getWorkflowServiceClient(),
                                           getIBPMContext(), task, null,
                                           "worklist", parameters);
        return url;
    }


    //courtesy of http://amulyamishras-tech-blog.blogspot.com/2011/01/opening-remote-http-url-inan-adf-dialog.html

    private TaskFlowId getTaskFlowDefinitionId(String detailsURL) {
        //Checks if the url is null.
        if (detailsURL == null)
            return null;
        //gets the parameter list from the url.
        String parameterList =
            detailsURL.substring(detailsURL.indexOf("?") + 1,
                                 detailsURL.length());
        //tokenizes the url.
        StringTokenizer stok = new StringTokenizer(parameterList, "&");
        String taskFlowId = null;
        String documentName = null;
        //gets the taskflowId from the url.
        while (stok.hasMoreTokens()) {
            String parameter = stok.nextToken();
            String[] parts = parameter.split("=", 2);
            if (parts[0].equals("_id"))
                taskFlowId = parts[1];
            if (parts[0].equals("_document"))
                documentName = parts[1];
        }
        //decodes the encoded url.
        try {
            documentName = URLDecoder.decode(documentName, "UTF-8");
            taskFlowId = URLDecoder.decode(taskFlowId, "UTF-8");

        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return new TaskFlowId(documentName, taskFlowId);
    }

    public void setProcess(ProcessMetadataSummary process) {
        this.process = process;
    }

    public ProcessMetadataSummary getProcess() {
        return process;
    }

    private IBPMContext getIBPMContext() throws Exception {
        if (bpmContext == null) {
            bpmContext = (IBPMContext)JSFUtils.getFromSession("BPM_CONTEXT");
        }
        if (bpmContext == null) {
            bpmContext = factory.getBPMUserAuthenticationService().getBPMContextForAuthenticatedUser();
        }
        JSFUtils.storeOnSession("BPM_CONTEXT", bpmContext);
        return bpmContext;
    }
}

The "initiable_task_list.jsff" page fragment:

<?xml version='1.0' encoding='UTF-8'?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.1"
          xmlns:af="http://xmlns.oracle.com/adf/faces/rich"
          xmlns:f="http://java.sun.com/jsf/core">
  <af:panelBox text="Applications" id="pb1">
    <f:facet name="toolbar"/>
    <af:panelList id="pl1">     
      <af:forEach items="#{viewScope.initiableTaskListForm.initiatiableTasks}"
                  var="process">
            <af:commandLink text="#{process.projectName}: #{process.processName}"
                      action="#{viewScope.initiableTaskListForm.initiateTask}" id="cl1"
                            useWindow="true"
                            windowModalityType="applicationModal">
          <af:setPropertyListener type="action" from="#{process}"
                                  to="#{viewScope.initiableTaskListForm.process}"/>
        </af:commandLink>
      </af:forEach>
    </af:panelList>
  </af:panelBox>
</jsp:root>

Sample Application

You can get the sample application from this link. The sample application needs to be deployed on a SOA server. On a subsequent post I will demonstrate how to run this sample on the integrated weblogic server.
In the sample, the InitiableTasksProject is deployed as an ADF library so it can easily be reused in other projects/ applications.

Cheers!