Oracle ADF Features

Oracle Application Development Framework (Oracle ADF) is an advanced Rapid Application Development(RAD) Framework for J2EE applications mainly targeted for B2B Applications.

It is a proprietary software maintained by Oracle in 3 flavors:

Features-

  • RAD Framework with most commonly used components of any Front End Application available as inbuilt feature
  • Model-View-Controller (MVC) design pattern and offers an integrated solution that covers all the layers of this architecture with solution to such areas as:
    • ORM and Data Persistence
    • Reusable Task-flow approach,
    • Rich Web user interface elements,
    • Data binding to UI,
    • Security
    • Customization via sandboxes etc
  • Separation of Business Logic implementation details, via metadata and use of this metadata-driven architecture enables developers to focus on the business logic and user experience.
  • Drag-n-Drop features, via JDeveloper IDE, provides the ease to use and customize.
  • ADF Skin Editor: New ADF Skin editor for visually creating and modifying the appearance of ADF Faces applications.(JDeveloper 11G and above)
  • JSF 2.0: JSF 2.0 support in the IDE and for ADF applications. (JDev 11g R2 release)
  • ADF Faces and Data Visualization Tools (DVT) support touch gestures for interactivity on the touch-enabled devices, such as touch support for drag and drop, tooltips, data tips, and context menus.
  • ADF Faces and DVT components are certified on iPad. Additionally, ADF DVT Graph and Gauge components support rendering in HTML5.
  • MDS is metadata service that is used to store metadata information. When you use ADF, it generates lot of internal files about its own components and DB binding details. All these are stored internally by ADF into MDS.
  • ADS (Active Data service)- This is used in ADF to push any data changes automatically from the back end into the portal layer. This is different from Ajax which is used to send request from UI to data service layer.

How to create a Custom ADF Component

In this tutorial, we will create a custom ADF Component.

Create new files and package structure as shown:

Structure
Create a Custom ADF Component

Source Code of the required files is as below:

Final Output:

final
Create a Custom ADF Component

Retrieve GET parameters from URL in Managed Bean in Oracle ADF

For obtaining parameter from URL in java code in Oracle ADF use the below code
URL:
http://127.0.0.1:7101/Application-ViewController-context-root/faces/page.jspx?paramName=Testing123
Use the code:
String test = FacesContext.
getCurrentInstance().getExternalContext().getRequestParameterMap().get("paramName");

Insert Rows in ADF View Object Programatically

Suppose that I have EmpVO view object which have below attributes
EmpId, FirstName, LastName

We can do inserting rows by two ways in data model layer (Application Model or View Object classes)
I will write my code in ApplicationModuleImpl class

try
{
    ViewObject vo=this.getEmpVO();
    Row r=vo.createRow();
    r.setAttribute("EmpId","id#1");
    r.setAttribute("FirstName","fn#1");
    r.setAttribute("LastName","ln#1");
    vo.insertRow(r);
    this.getDBTransaction().commit();
}catch(Exception e){
    e.printStackTrace();
}

When and how much to mix technologies for a project?

The main idea behind using a technology is to harness the power of code re-usability and libraries that have already been worked on and trusted to be working and functional with minimal or no issues.

The term “Technology” does not just refer to Java or C++ or JavaScript. It also refers to the frameworks that can be used to suffice some or the other requirements with minimum cost and minimal effort investment. One example can be any Application Development Framework Like Oracle ADF, Pega or Drupal, etc. The framework itself provides functionalities that are most common and also takes cares of the issues that people face while developing an application.

Any application which has to be developed from scratch needs a lot of work just to be useful enough to be used in Production environment. Basic Non-functional requirements such as MVC Architecture, Security safeguards, Application Performance, etc. are the basic and most common features of the application. In addition, Secure Login, User Registration and authentication, role mapping and similar features are also mandatory features of the application.

Most frameworks provide features such as configurable work flows, built in UI Elements, security aspects and many other features. Features such as SQL Escaping, HTML Tag Escaping and MVC Pattern architecture are generally already inbuilt to the framework. The developers can simply configure the workflows, create screens and corner out application logic and then the application is good to go.

But is that enough that we may need??

This the main question that we need to ask when trying to select technologies and try to mix them to achieve the application requirement. The Case study can be a sample B-2-B Application say Business-2-Go (B2G).

Advantage of Techs to be selected:

The B2G can be based on 3 major technology products namely an Identity Management System, an Application Development Framework, and a Content Management Service. The technologies in combination provide the architecture to harness the features out of the box.

The IDM would provide Session Maintenance, Role Mappings, Access Authentications and invalid access handling.

CMS on the other hand takes care of the static content of the application. This technology handles the application content which needs to be configurable but would be changed in very rare scenarios. The main usefulness lies in the fact that the CMS portal can be exposed to the customer admin team as well and be comfortable as the code base will not be touched by the Non Development User.

The ADF constitutes to the application flow of the B2G. All user interactions and other business logic is handled by this technology. The flexibility of the framework helps create applications quickly and more efficiently than the older technologies/frameworks such as J2EE Servlets/JSP or struts and so on.

Further technologies like JavaScript, jQuery, CSS have been used to achieve the look and feel that was decided by the client.

Disadvantages of Techs to be selected:

The disadvantages or rather limitations of the tech or the team using the tech is the one that decides whether the tech can be used or not.

The major factors can be:

  • Cost: The technology that has been perfected and supported may be in most cases be licensed. Thus incurring costs to the budget of the project. The alternative may be using Open Source technologies/frameworks. But there the problem exists of the credibility of the source, issue support and whether documentation is enough or not.
  • Resource Availability: Assuming that the cost barrier of the license has been overcome. Now the major concern is whether the resources for the technology are available or not. If not, then can existing resources be trained or can new resources can be acquired. Again the cost factor is affected in this concern.
  • Technology Limitations: Technologies have limitations in themselves also. The limitation may not be a feature that cannot be achieved, but the effort that may be involved in achieving the feature. A simple example may be a particular look and feel of a B2G. Many of the UI Elements may or may not be achievable with the selected core ADF. Or even if they are achievable, it is after a lot of R&D or with lot of hit and trials. Though this is not something that may rule out the technology itself, but may be enough to include other technologies like jQuery into the picture.
  • Interfacing efforts: While mixing technologies, spots/hooks need to be found where 1 tech may latch on to or may be placed in with the other. For example, jQuery is an Independent Tech and in the selected ADF, generally has an internal client side scripts are functioning on its own end. There may be provisions which execute scripts that achieve the UI functionalities. Similarly the CMS may not have stable out of the box connectors to code layer of the application. Thus interfaces are written to implement make this possible. This effort may also turn out to be a concern for using a tech.

An example of tech selection may be PHP. The technology PHP can also be used for creating a complete application and 99% of the same application can be achieved using PHP frameworks. In fact the cost of the tech is 0 (Open Source) and resource costing would be way lower than those of licensed application framework. But the efforts and timescale needed to achieve all the functionalities required will be humongous. Thus ruling out the tech.

Another concern that can be raised is how much the technologies can be mixed. Surely each of the frameworks will be providing some or the other comfort or a feature. Even if they are published in open source or you may have license available. Does that mean that all technologies should be mixed..??

Interfacing technologies uses effort. It also invokes limitations. An example may be the various attempts to integrate popular front-end framework like AngularJS with Oracle ADF. Oracle ADF is a mainly a Server Side Technology, maintaining all functionalities server side and providing a wide palette of features for an application. AngularJS on the other hand is a completely UI framework. It is completely Client Side Intensive Tech. Both frameworks are completely in the opposite directions. Both are unaware of the other. There are blogs showing way how to integrate both the technologies. But all can point out the issues in the integration. This is a small example, but scaling this, similar issues may be faced and thus may be counted as factors in Tech Selection.

In Conclusion, the trade-offs govern the selections of the technologies to be used in a project. Proper selections must be made in order to plan out the architecture. Improper selection may lead to issues, crashes, late deliveries or redundant costs.

References:

Image: https://www.systrends.com/sites/default/files/banner/appdev_banner2.jpg

How to add DVT Graph Programmatically

This tutorial is to show how to inject a DVT graph programmatically in Oracle ADF

Step 1: Define a List Data Model:

Java Code for Data

        List<Object[]> listObject = null;
        if (listObject == null) {
            listObject = new ArrayList<Object[]>();
            Object[] obj1 = { "Example_Bar_1", "Series_1", 10 };
            Object[] obj2 = { "Example_Bar_1", "Series_2", 15 };
            Object[] obj3 = { "Example_Bar_1", "Series_3", 75 };
            listObject.add(obj1);
            listObject.add(obj2);
            listObject.add(obj3);
        }

JSFF Code where the code will be injected:

<?xml version='1.0' encoding='windows-1252'?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.1"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:h="http://java.sun.com/jsf/html"
 xmlns:af="http://xmlns.oracle.com/adf/faces/rich"
 xmlns:dvt="http://xmlns.oracle.com/dss/adf/faces">
 <jsp:directive.page contentType="text/html;charset=windows-1252"/>
 <f:view>
 <af:document title="demo" id="d1">
 <af:form id="f1">
 <af:panelGroupLayout id="pgl1" styleClass="container" binding="#{backingBeanScope.graphBean.container}"/>
 </af:form>
 </af:document>
 </f:view>
</jsp:root>

Java Code to inject Graph @ Runtime:

[Note]:container is the binding to the af:panelGroupLayout under which you wish to inject the graph
        List<Object[]> listObject = null;
        if (listObject == null) {
            listObject = new ArrayList<Object[]>();
            Object[] obj1 = { "Example_Bar_1", "Series_1", 10 };
            Object[] obj2 = { "Example_Bar_1", "Series_2", 15 };
            Object[] obj3 = { "Example_Bar_1", "Series_3", 75 };
            listObject.add(obj1);
            listObject.add(obj2);
            listObject.add(obj3);
        }
        UIGraph graph = new UIGraph();
        graph.setGraphType(UIGraph.PIE);
        graph.setTabularData(listObject);
        container.getChildren().add(graph);

Result:

2015-08-14_1742

 

How to add ValueChangeListener Programmatically

Using an EL String, we can add ValueChangeListener in Oracle ADF using the below code:

private static MethodBinding getValueChangeListener(String el) {
        Class[] parms = new Class[] { ValueChangeEvent.class };
        MethodBinding mb =
            FacesContext.getCurrentInstance().getApplication().createMethodBinding(el,
                                                                                   parms);
        return mb;
    }

pass the EL Expression to the util method

ui.setValueChangeListener(getValueChangeListener("#{pageFlowScope.demoBean.valueChangeListener}")); 

 

How to Add an ActionListener programmatically

Using an EL String, we can add ActionListener in Oracle ADF using the below code:

private ActionListener getActionListener(String el) {
        //here Testbean is the name of ManagedBean
        MethodExpression methodExp = getMethodExpressionForAction(el);
        return new MethodExpressionActionListener(methodExp);
    }
private MethodExpression getMethodExpressionForAction(String actionName) {
        Class[] argtypes = new Class[1];
        argtypes[0] = ActionEvent.class;

        FacesContext facesCtx = FacesContext.getCurrentInstance();
        Application app = facesCtx.getApplication();
        ExpressionFactory elFactory = app.getExpressionFactory();
        ELContext elContext = facesCtx.getELContext();
        return elFactory.createMethodExpression(elContext, actionName, null, argtypes);
    }

pass the EL Expression to the util method

ui.addActionListener(getActionListener("#{pageFlowScope.demoBean.actionListener}"));