Thursday, 15 May 2008

Oracle ADF: A view object with cancelInsert and cancelEdit operations

I have already discussed the problem of providing a cancel button in an ADF/JSF edit page. Here is an alternative that allows the usage of a base view object that provides both a cancel edit and a cancel insert method.

I have come to believe that this method is the most appealing so here is a brief outline of how to use it :

First create the following class in the queries package of you model application.

package myapp.model.queries;

import oracle.jbo.Row;
import oracle.jbo.server.ViewObjectImpl;

public class AB_BaseViewObject
    extends ViewObjectImpl {

    public AB_BaseViewObject()
     * Refresh the view obejct's current row from the dataset practically 
     * undoing any changes.
    public void cancelEdits() 
        Row r = getCurrentRow();

        if (r != null) 
            r.refresh( Row.REFRESH_WITH_DB_FORGET_CHANGES);
     * Undo changes and get rid of new rows
    public void cancelInsert()

Next create Java Classes that extend the AB_ViewObject for all the view objects that require editing in your project. Publish the cancelXXX() methods on the view interface like in following picture.

Finally create buttons on the edit or create pages in the ViewController project that call the methods.


polz said...

Thanks for these handy tips!

I have added based on your code a cancelAllEdits() method on the VO that loops through all rows with getAllRowsInRange() and this works fine. However, deletions are not canceled. Any idea on how to implement this?

Athanassios Bakalidis said...

How about a rollback ? I think that this is the only way to undo deletions. If you need more help on this try the article on the Dive into ADF and BC4J page regarding how to retain the current row after rollback.