ADF Dynamic Region | Working with Oracle ADF Dynamic Regions

ADF Region is used to render a bounded taskflow in a JSF page . The primary use of ADF Region is u can put  various pieces of application functionality in a bounded task flow. A single JSF page can contain many taskflows added as regions and each region may contain different content.

The sections pointed with arrows are different taskflows added as as a regions in a single JSF Page.The Taskflow which is added as ADF Region must contain at least one view activity.

Difference between ADF Region and Dynamic Region ?

Region added in a JSF Page can be invoked based on some action like button click or link that renders specific taskflow in which the region formed . various regions can also be displayed as a stand by at a time when the page loads.In Dynamic Region you do not need to drag and drop the required regions on to the JSF page instead your taskflows will be identified by using the taskflow ID on some action. The task flow binding dynamically determines the values of its ID at run time . In the above picture i have dragged and dropped four taskflows as a region in a JSF Page . But Dynamic Region simplifies this and allows us to swap between taskflows using Dynamic Region link where it store the task flow id in a managed bean and render the pages based on the task flow ID it gets at runtime .

Hope this gives you the basic idea on the concept and we will move ahead for creating one .

Download sample application with this post 

we are not going to alter our Model project as we will use the existing VOs which we created in earlier posts .Those who want to continue with the workspace that contains all model components can download from here AdfDemoApps.

Create two taskflows :
AdfDemoApps\AdfDemoUi\public_html\WEB-INF\TaskFlows\CountriesFlow.xml,
AdfDemoApps\AdfDemoUi\public_html\WEB-INF\TaskFlows\EmployeesFlow.xml

Create two page fragments :
AdfDemoApps\AdfDemoUi\public_html\pages\CountriesRegionPage.jsff
AdfDemoApps\AdfDemoUi\public_html\pages\EmpRegionPage.jsff

Drag & drop the CountriesRegionPage.jsff in CountriesFlow.xml and  EmpRegionPage.jsff in EmployeesFlow.xml.We need a jsp page to run these taskflows. Create a JSF Page DynamicRegionMain.jspx under AdfDemoApps\AdfDemoUi\public_html\pages. In the Create JSF Page dialog under Initial Page Layout and Content section i have selected Oracle Three Column Layout for the rich look and to split the user screen into two so that we can have action links at one side and actual pages at other side.

Now Drag and drop the EmployeesFlow.xml into the DyamicRegionMain.jspx we just created and select Dynamic Region. In the Next step it will ask you to specify Managed Bean . Click Add symbol  and create one .  Bean name is DynamicRegionBean under package bean and click ok. you can also create managed bean separately and  choose from the drop down. click ok in the Edit Task Flow Binding dialog.

The next two steps are important

Drag and drop the EmployeesFlow.xml  in the left panel of the page and choose Dynamic Region Link > dynamicRegion1.
Drag and drop the CountriesFlow.xml  in the left panel of the page and choose Dynamic Region Link > dynamicRegion1.
As we already have one Dynamic Region we are appending our taskflows to the same region link .

When you drop a taskflow onto a JSF page to create an ADF dynamic region , JDeveloper adds an af:region tag to the page . This tag contains a reference to a task flow binding

<f:facet name="center">
            <af:region value="#{bindings.dynamicRegion1.regionModel}" id="r1"
                       partialTriggers="::cl1 ::cl2"/>
 </f:facet>

An ADF dynamic region link swaps the taskflows within an ADF dynamic region . Look at the below code snippet in the DynamicRegionBean. java
 
Jspx :

     <af:commandLink text="EmployeesFlow"
                              action="#{viewScope.DynamicRegionBean.employeesFlow}"
                              id="cl1"/>
              <af:spacer width="10" height="10" id="s1"/>
      <af:commandLink text="CountriesFlow"
                              action="#{viewScope.DynamicRegionBean.countriesFlow}"
                              id="cl2"/>
Bean :

    private String taskFlowId =
        "/WEB-INF/TaskFlows/EmployeesFlow.xml#EmployeesFlow";

    public DynamicRegionBean() {

        super();

    }

    public TaskFlowId getDynamicTaskFlowId() {

        return TaskFlowId.parse(taskFlowId);
    }

    public String employeesFlow() {

        taskFlowId = "/WEB-INF/TaskFlows/EmployeesFlow.xml#EmployeesFlow";
        return null;
    }

    public String countriesFlow() {

        taskFlowId = "/WEB-INF/TaskFlows/CountriesFlow.xml#CountriesFlow";
        return null;
    }

The Managed bean stores the value of the task flow ID that displays inside the dynamic region
when a user click on any link its corresponding method will be called and thus taskFlowId will be changed and corresponding page will be rendered.

Note :
you can add an ADF Dynamic Region Link if you already have at least one ADF Dynamic Region on a page. a menu displays all of the dynamic regions currently on the page

Save All .  Right Click on DynamicRegionMain.jspx and choose Run . The Output