Restrict navigation on the basis of value

Question

There is a supplier table. If the status of the supplier row is DRAFT or NEW, then only will I be able to see the details of it by clicking on a commandlink. For this, I had attached a property listener to get the value #{row.Status} and then wrote the logic code in the ActionListener property of the commandlink as below.
public void moveToDetailPageBasedOnStatus(ActionEvent actionEvent) {
        DCBindingContainer bc = (DCBindingContainer)BindingContext.getCurrent().getCurrentBindingsEntry();
        Map map = bc.getParametersMap();
        String status = ((DCParameter)map.get("p_status")).getValue().toString();
        if (status.equals("DRAFT")) {
            FacesContext context = FacesContext.getCurrentInstance();
            context.getApplication().getNavigationHandler().handleNavigation(context, null, "create");
        } else {
            FacesContext context = FacesContext.getCurrentInstance();
            FacesMessage msg2 =
                new FacesMessage(FacesMessage.SEVERITY_INFO, "", "User can see the details of an Issue in DRAFT Status only.");
            context.addMessage(null, msg2);
    }Then I read the comment by Frank Nimphius in the post below, saying that "+Why don't you use a method call activity or (even better) a router) if it is all about directing different users to different views? The approach of using HandleNavigation is not optimal+".
FacesContext context = FacesContext.getCurrentInstance();
            context.getApplication().getNavigationHandler().handleNavigation(context, null, "create");
http://www.adftips.com/2010/10/adf-ui-navigating-to-next-page.htmlSo then I am passing a parameter to a bounded taskflow where I am defining a pageFlowScope parameter, and then created a method call activity, set it as the default activity. The code is almost the same.
public void checkIssueStatus() {
        String value = (String) ADFContext.getCurrent().getPageFlowScope().get("p_status");
        if ((value.equals("DRAFT")) || (value.equals("NEW"))) {
            FacesContext context = FacesContext.getCurrentInstance();
            context.getApplication().getNavigationHandler().handleNavigation(context, null, "checked");
        } else {
            FacesContext context = FacesContext.getCurrentInstance();
            FacesMessage msg2 =
                new FacesMessage(FacesMessage.SEVERITY_INFO, "", "User can see the details of an Issue in DRAFT Status only.");
            context.addMessage(null, msg2);
    }The problem is in case the p_status is other than NEW or DRAFT, the message is getting displayed, but then detail page is also shown. I only want to display the message only and not navigate to the next page. How to resolve this issue?
And the big question: Is my approach correct and optimal this time?

Answer 1

No as you already know it the same approach you used before.
In your task flow you use a router element as start activity wher you check the parameter using EL and depending on the outcome navigate to the view you like.
<?xml version="1.0" encoding="UTF-8" ?>
<adfc-config xmlns="http://xmlns.oracle.com/adf/controller" version="1.2">
  <task-flow-definition id="router-task-flow-definition">
    <default-activity>router1</default-activity>
    <router id="router1">
      <case id="__1">
        <expression>#{pageFlowScope.pStatus eq 'NEW'}</expression>
        <outcome>outcome1</outcome>
      </case>
      <case id="__2">
        <expression>#{pageFlowScope.pStatus eq 'INIT'}</expression>
        <outcome>outcome2</outcome>
      </case>
      <default-outcome>outcome3</default-outcome>
    </router>
    <view id="view1"></view>
    <view id="view2"></view>
    <view id="view3"></view>
    <control-flow-rule id="__3">
      <from-activity-id>router1</from-activity-id>
      <control-flow-case id="__4">
        <from-outcome>outcome1</from-outcome>
        <to-activity-id>view1</to-activity-id>
      </control-flow-case>
      <control-flow-case id="__5">
        <from-outcome>outcome2</from-outcome>
        <to-activity-id>view2</to-activity-id>
      </control-flow-case>
      <control-flow-case id="__6">
        <from-outcome>outcome3</from-outcome>
        <to-activity-id>view3</to-activity-id>
      </control-flow-case>
    </control-flow-rule>
    <use-page-fragments/>
  </task-flow-definition>
</adfc-config>This way the navigation is handled by the controller without using the navigation handler.
A full sample you can find here: http://tompeez.wordpress.com/2012/12/01/jdeveloper-11-1-1-5-0-use-router-to-create-new-row-or-edit-existing/
Timo