How to clear the data from the VO when pop-up is cancelled

In ADF we usually use the pop-up for entering the data. Sometimes we don't want to save the data which we entered in the pop-up form, user may press the Esc button or click on cancel, but still the data will be added to the corresponding VO. So how to clear the data or row which is added in that VO.

In the below example we will see how to clear the data form the pop-up.

In the PopupFetchListner call the managed bean to create new row in the VO.

public void addNewItem(PopupFetchEvent popupFetchEvent) {

        DCBindingContainer bindings =                         (DCBindingContainer)BindingContext.getCurrent().getCurrentBindingsEntry();

        OperationBinding operationBinding = (OperationBinding)bindings.getOperationBinding("CreateInsert");

        operationBinding.execute();
}
The popup will be appeared with the empty fields. and you can add the data to the popup.

When you click on the cancel button, you want to clear the data which you have entered. 

To do so, you have to call the managed bean trough the popupCanceledListener property of the popup.

To clear the popup, get the iterator through th BindingContext, and DCBindingIterator classes as show in below code snippet.

    public void clearPopUp(PopupCanceledEvent popupCanceledEvent) {

        // Add event code here...

        

        DCBindingContainer bindings =(DCBindingContainer)BindingContext.getCurrent().getCurrentBindingsEntry();

        DCIteratorBinding orderItemIterator = bindings.findIteratorBinding("OrderItemsVO2Iterator");

        ViewObject viewObject = orderItemIterator.getViewObject();

        viewObject.clearCache();

        viewObject.executeQuery();

        System.out.println("Cashe is cleared");

    }

Now on click of esc button on keyboard, or cancel button on in the popup, this managed bean will be called and the VO cache gets cleared.



NOTE: Make sure that the popup "contentDelivery" property is set to lazyUncashed. if you make it "immediate" the managed method wont be called and VO cache wont get cleared.

What is Data Control Scopes and Data Control Frame

ADF transactions are defined by the business service implementation used in the application (Application Modules). Application Modules provides the connections and transaction to commit the data into the DB. The AM are exposed to the ViewController layer through an abstraction called Data Control.

By default AM provides transaction for the application to commit the data into the DB. But the developer has the ability to change the transaction flow. Each bounded task flow provides its own transaction and data control scopes, example each bounded task flow can commit data separately or use the default transaction.

In the below image you can see simple bounded taskflow with transaction options.

For a given btf (Bounded Task Flow) there are 4 transaction options.

I)                    No Controller Transaction (btf use the existing default transaction)

II)                  Always Begin New Transaction (btf creates new transaction)

III)                Always Use the Existing Transaction (btf uses the existing transaction)

IV)               Use the Existing Transaction If Possible.

Each btf data control scopes provides option to share the transaction with the other btf or not. It provides 2 options

i)                    Shared

ii)                   Isolated

“Shared”: will try to share any instance of a data control with the task flow's caller if the data controls have the same definition, rather than creating a new instance.

“Isolated”: Even if both task flows use the same design time data control definition, at runtime

 each task flow will have their own instance of the data control.

There is something called Data Control Frame which handles all the data control scopes. Each task flow has its own data control frame and containing list of data control scopes.

A data control frame is created at run-time for the application’s unbounded task flow and for each isolated data control scoped bounded task flow. When bounded task flow specified the shared data control scope and the current task flow uses the data control frame and the instances attached to it.

Alternatively if the bounded task flow specifies an isolated data control scope, a new

frame will be created and a new instance of any data controls used by the bounded task flow will

be attached to this new frame.

The below image shows when the new Data Control Frame is created

As you can see in the above diagram there are three Data Control Frame gets created. The red arrow shows that when the data control scope of the BTF is selected as isolated new Data Control Frame gets created. And when the BTF is Shared, the called BTF uses the dame Data Control Frame and instances attached the same.

How to pass values between pages within a task flow and other task flow using pageFlow and request scope

I have scenario to pass value from one page to another page within a task flow or may be other task flow.

ADF provides some scopes for example, pageFlow, request, session and application. Using some of these scopes we can hold the value of variable throughout the application.

In this post we will see how to use pageFlow and request scope. 

pageFlow scope is used to pass parameter between the pages within a task flow. 

request scope is used to pass parameter to another page which is there in different task flow.

I have 2 pages in a default unbounded task flow(first task flow), page1 and page2. I have created one bounded task flow(second task flow) which has one page fragment ie page3.

Unbounded Task Flow

 Bounded task Flow

Create the pages by double clicking on each node in the task flows.
Two pages and one fragment gets created
page1.jspx(or .jsf)
page2.jspx(or .jsf)
page3.jsff


In page1 i have one text field(username) and one button. When i click on submit button page2 will be shown.
Page 2 has one output text field to show the value entered in the page1 and one region. The region contains the contents of the other task flow(ie page3).

In the page1 bind the username to some existing managed bean, if not create new one and bind it(i have created one with the name testScopeBean and make sure that the bean scope is pageFlow in the task floew ie adfc-config.xml). It will create getter and setter methods. And create one instance variable where you want to store the value of the username. And generate the getter and setter methods for the instance variable(scopeVariable)

On click of submit button call the actionListner and store the value of username into the scopeVariable in the testScopeBean.
Managed bean code is show below.


public class TestScopeBean {
    private RichInputText username;
    private String scopeVariable;

    public TestScopeBean() {
    }

    public void setUsername(RichInputText username) {
        this.username = username;
    }

    public RichInputText getUsername() {
        return username;
    }
    
    public void setScopeVariable(String intVar) {
        this.scopeVariable = intVar;
    }

    public String getScopeVariable() {
        return scopeVariable;
    }

    public void getUserName(ActionEvent actionEvent) {
        // Add event code here...
        RichInputText userName = (RichInputText)FacesContext.getCurrentInstance().getViewRoot().findComponent("it1");
//it1 is the id of input text field
        String userName1 = (String)userName.getValue();
        System.out.println("user name "+userName1);
        setScopeVariable(userName1);
    }
}

Now you can use the scopeVariable in the other pages within a task flow like
af:outputText value="pageFlow scope variable #{pageFlowScope.testScopeBean.scopeVariable}"  id="ot1"/>

Run the page1.jspx and enter the user name and click on the submit button you can the result in page2.jspx.

You use the same pageFlow scope variable in other task flow also, but it will show blank value. Because pageFlow Scope value is restricted to only within task flow

Now change the managed bean scope to request in the adfc-config.xml managed bean tab.
The request Scope variable can be access like #{testScopeBean.scopeVariable}
Change the the wherever you have used the #{pageFlowScope.testScopeBean.scopeVariable} to #{testScopeBean.scopeVariable}.

Run the page1.jspx again and see the result, now it will show value in other task flow also.

Deleting the child records when the master records gets delete

We go for association when there is relation between the two tables. For example Order and Order Items. When we delete the Order then Order Items under that Order should get delete.  How can we achieve this?. There is an option provided by the ADF framework  association called "Implement Cascade Delete". Just we need to select that option, automatically the ADF framework will handle the master-child record.

First create the associations between the order and Items, if the association did not get create while creating the Entity Objects for the Order and OrderItems as shown in the below image

After creation of Association, open the association, go to the Relationship tab and expand the Behavior options at the bottom. Select the Composition Associations check-box, then select the Implement Cascade Delete check-box as shown in the below image .

Now if you delete the master record, automatically the child record gets delete.