OAF Interview questions and answers -2

Ques:- What is the pattern used in developing any OAF component?
Ans:-  MVC (Model, View, Controller)

Ques:-  Lists the components in the MVC architecture
Ans:-   Model: Application Module, View Objects, View Links, Entity Objects, Entity Associations etc.
            View: Page, Region, Attributesets etc.
            Controller : Controller class files


Ques:- Which is the component responsible for user actions?
Ans:-  Controller is the object. The code present in ProcessFormRequest gets executed up on the user action.

Ques:- If  we have to initialize something during the page loading, which is the right place?
Ans:-  ProcessRequest() method of the Controller file is the right place.

Ques:- What is the significance of ProcessFormData()?
Ans:-  For  a ‘POST’ request the data on the page is binded to the view object in this method

Ques:- Does ‘GET’  request result in calling ProcessFormData()?
Ans:-  No, only POST request calls that.

Ques:- What is the main Controller component in OAF?
Ans:-  OAController is the main class and our controller will become subclass of it.

Ques:- How does page structure get created at runtime?
Ans:-  OAPageBean is responsible for creating the bean hierarchy structure at runtime after calling ProcessRequest() of each of the beans in the hierarchy.


Ques:- Where does the client BC4J objects get placed in the server?
Ans:-  They are located in the oracle.apps.<product>.<application>.server


Ques:- Where does the server BC4J objects get placed in the server?
Ans:-  They are located in the oracle.apps.<product>.<application>.schema.server

Ques:- Where does the Page and Controller related files get placed?
Ans:-  They are located in oracle.apps.<product>.<application>.webui

Ques:- What are Validation View Objects?
Ans:-  They are the VVO’s used in validation of attributes, they are the BC4J components and have their AM ie VAM Validation Application Module

Ques:- What is the version of Jdeveloper to be used in 11i or R12?
Ans:-  For 11i, Jdeveloper 9i will be used and for R12 Jdeveloper 10g will be used.

Ques:- What is a Database Connectivity File?
Ans:-  It is a .dbc file which is specified in the project properties. The location of this file on the server is $FND_TOP/secure

Ques:- What is a View Object?
Ans:-
      It is a BC4J(Business Component for Java) object which encapsulates the query results. View objects will support the display of the content to user in  the Page.

Ques:- How do you create a view object?
Ans:-
      View objects can be created in the Business components package, can be based on entity objects or an sql query. View objects based on sql query are read only view objects

Ques:- What is an entity object?
Ans:-
      Entity object is created based on a database table, it is responsible for insertion/updation/validation of the table data. They are stored in the oracle.apps.<prod>.<application>.schema.server package directory

Ques:- What is an Application Module(AM)?
Ans:-
      Application module holds the related objects pertaining to an application  ie. View objects, Entity Objects etc. The application module helps in getting the required database connection, maintains the page session or transaction context

Ques:- What is the object passed to every page request?
Ans:-
      OAPageContext object is passed to every request, using this object the controller initializes the application module object and will call the required methods.

Ques:- Where is the view object(VO) initialization  or  query filtering done?
Ans:-  It is done with view object implementation class Ex. EmpVOImpl.java

Ques:- What is the property to set for an AM so that the transaction state is maintained across pages?
Ans:-  RETENTION_LEVEL property is set to value MANAGE_STATE for an AM.

Ques:- What is the Personalization?
Ans:-  Personalization means changes to the existing ‘Page’ according to the customer requirement

Ques:- Give some examples of Page Personalization?
Ans:-
      Addition of new columns to a table results, adding of fields, changing the order of regions, columns etc. Apart from this validation of certain fields, display of Descriptive flex fields etc can also be achieved

Ques:- What is extension?
Ans:-
      Extension is the changing of the existing components for adding more features or customer required features. View Objects, Controller, Application Module can be extended.

Ques:- What is substitution?
Ans:-
      When view objects are extended, we need to tell the applications that our extended view object should be used or substituted during runtime, substitution will serve this purpose

Ques:- How to do register a new OA Framework page in Oracle Applications?
Ans:-
       oracle.jrad.tools.XMLImporter utility will be used. After successfully importing the page data will be stored in metadata repository tables of the database

Ques:- How do you move personalization from one machine to another?
Ans:-
      Using the functional administrator responsibility the xml file can be downloaded, this file contains the required personalization done on a particular page. The same can be used to upload in a different instance. Here XMLImporter utility can be also used.

Ques:- How is the applications security maintained during the OA Framework components development or how is the required security obtained?
Ans:-
      The Database connectivity file ( .dbc file) has the applications username and password along with the responsibility to  be used for connecting to the applications at page run time.

Ques:- What are the different layers of onion reuse object model in OAF?
Ans:-
      The hierarchy is as :
      Controller (XXCO.java)
                       |__
                            Application Module   (XXAMImpl.java, XXAM.xml)
                                       |__
                                        View Objects(XXVOImpl.java, XXVORowImpl.java, XXVO.xml)
                                                  |__
                                                     Entity Objects(XXEOImpl.java, XXEO.xml)
                                                             |_ Database          



Ques:- What is ‘Partial Page Rendering’ PPR?
Ans:-
      PPR is a mechanism where in only the required part of the page is refreshed as against the whole page. The page objects fire the ‘events’ and accordingly the request is handled in the controller file

Ques:- What are the search region options available?
Ans:-  Simple Search – ResultBasedSearch is the construction  mode for the region
       Advanced or autocustomization search – Autocustomization is the mode here
       None – User has the develop the page, regions, controller etc here

Ques:- What is the bean used for supporting transactions across pages visually to the user?
Ans:-  OATrainBean is used to link the pages across the transaction. AM supports the transaction context or state here across the pages.

Ques:- How does personalization takes its effect at runtime?
Ans:-
       After the page structure or bean hierarchy is formed with, the personalization layers get applied on top of it to come up with the final structure. Remember that is the reason why personalization is upgrade safe.

Ques:- Name some components requiring extension?
Ans:-  View Objects, Controller, Application Module. Yes nested application module concept is allowed.

Ques:- After you modify a class file and move it to the server what is the immediate step that will be followed?
Ans:-  The services of the instance ie. Apache server etc. have to be bounced so that the new code in the class file takes effect.

Ques:- Where does the two categories of files in OAF be placed in the server?
Ans:-
      All the xml files of the page/region will be placed in the respective TOP’s mds directory. All the class files irrespective of TOP will be placed under $JAVA_TOP which can be $COMMON_TOP/java

Ques:- When do you create additional business components package?
Ans:-
      Apart from B4CJ client business components package and B4CJ server business components package we create additional business components package when we develop any sharable thing such as ‘LOV’ (List of Values), ‘Poplist’ etc which will be used in multiple pages

Ques:- How do you map the LOV created to your base page?
Ans:-
      One of the items in the page has to be MessageLOVInput which extends the new LOV region, apart from this LOV mappings between base page and LOV region have to be created.

Ques:- What is the default top region of any new page that you create?
Ans:-  PageLayout is the top level default region

Ques:- At what level region controller for a page can be set?
Ans:-
       It can be under a Main region under PageLayoutRegion or any region as per the business need. Provision of defining multiple controllers for a page also exist.

Ques:- PPR follows GET or POST flow?
Ans:-  POST flow

Ques:- What is the extension to the tool for developing OA F components?
Ans:-  Jdeveloper OA Extension class support the OA F development

--All the Best