What is SAP WebDynpro? Concept of WebDynpro (ABAP centric)

Hi friends,

I believe that the concept of WebDynpro is more important than just creating a WebDynpro application. There are enough documents on the net on how to create a WD application. But there are very few documents which will give you the concept of WebDynpro.

I am making an effort here to provide the basics, concept and architecture of WebDynpro, with ABAP in mind.

Pre-requisite assumed: Knowledge of ABAP

What is WebDynpro?
WebDynpro is SAP's model or approach towards web screen design. SAP aims to achieve a clear distinction between UI design and backend code through this model. Dynpro means Dynamic Program, (SAP's terminology for interactive UI). hence Web Dynpro means Web screen. WebDynpro is also a latest model by SAP. Earlier approaches include ITS (Internet Transaction Sever) and BSP (Business Server Pages).

What is the programing language used for WebDynpro?
For the WebDynpro both ABAP and Java can be used. ABAP being the latest and also seems to be the future for WebDynpro. View my WebDynpro articles here.

Future of WebDynpro: ABAP or Java?
Story of WebDynpro. Who is the hero? ABAP or Java ?

What is a View?
View is a layout of UI elements. Example of UI elements is Input field, Output Filed, Radio buttons etc.
View also contains the methods which are local to the view.

What is a Window?
Window is a group of Views. One of the View will be a default View. Navigation to other views of the Window can happen only from the default view.

What is a inbound/Outbound Plug ?
Plugs are used to navigate between Views. Inbound plugs define inbound connections to a view, and Outbound plugs define subsequent View for a View.

What is a WebDynpro Component ?
WebDynpro Component can contain other WD Component, Windows and Views.
WebDynpro Component is a reusable entity. It can be reused by another component so that re-usability is achieved.
Hierarchically WD Component is at the highest level within a WD model.

What is a Interface View ?
Every Window is accessed by an Interface view.
Name of the Interface View will be same as Window.
Interface View defines inbound and outbound Plugs for a Window.

What is WebDynpro Application?
WebDynpro Application provides a way to use the functionality built using a WebDynpro component.

A WebDynpro application is defined by following three parameters
1. A WebDynpro application refers to ONE WebDynpro Component,
2. A WebDynpro application refers to ONE Interface View (of the above WebDynpro component),
3. A WebDynpro Application has a URL, so that it can be accessed from a browser.

What is the link from a WebDynpro Application till a view?
A WebDynpro URL points to a WebDynpro Application.
A WebDynpro Application points to an Interface View.
A Interface View points to a Window.
A Window points to its default View.

What is a View Context?
The data used in a View is stored in a object called View Context.

What is an Action?
For certain UI elements like Button, you would want some action to happen when the button is pushed.
So Action is defined at UI element level.
As soon as a Action gets created, a handler method gets automatically created by name HandleUIEvent_ in the View Controller. In this method you can define the behavior of the action.

What is a Component Context?
The data used in a Component is stored in a object called as Component Context. Component Context is global within a OCmponent.

What is a View Controller?
In SE80, you cannot see any object called as “View Controller”. The code related to View is located in the “Method” tab of the View. This is logically called as a View Controller.

What is a Component Controller?
Component Controller has the Programming part of a Component.
It is an object visible in SE80. It contains the methods which are global within the Component. I.e. These methods can be accessed by all objects within the Component

What is the future of SAP WebDynpro: ABAP or Java?

One of the hottest debate in SAP Technology area is that of future of WebDynpro. This quesiton will determine career path of several SAP professionals.

What is SAP's preferred approach? What is the technology SAP is delivering its current and future WebDynpro applications?
SAP's preference matters a lot and can be a key factor in determining the future of WebDynpro.

SAP's Historical preference
SAP's historical preference was clearly for Java. SAP first came up with Java WebDybpro framework. Java gurus were smitten by this WebDynpro framework and were too eager to develop applications using this user friendly framework. SAP's move towards Java gave ABAPers nightmares. ABAP professionals started shivering thinking about their careers and expected SE80 to become a history. The huge availability of Java developers meant that SAP's developer world will soon be baptized in to Java and ABAPers would find themselves out of place.

SAP built several standard applications is WDJ. (ESS and MSS). So ABAPers' nightmare was looking more real.

But all was not yet lost for ABAPers. WDJava still had to use ABAP in the form of RFCs. Core R/3 was still in ABAP and SAP would need to invest significantly if it had to convert its core into Java and this was unrealistic.

Then came the Knight rider for ABAPers. SAP introduced WebDynpro for ABAP somewhere in 2006. This added to the chaos and confusion althogh it was a light at the end of tunnel for ABAPers. More over, SAP did not provide any official direction on WebDynpro development and the WebDynpro started searching for the SAP insider information. But it turned out that SAP itself was confused. People from Palo Alto labs said Java is the future, but those from Germany labs said ABAP is the future.

Webdynpro Java framework is nearly 18 months mature compared to Webdynpro ABAP. So WDJ had an advantage initially. But It is fading as the time is progressing. Now SAP started delivering its recent standard applications in ABAP. So the balance started tilting towards ABAP. Being part of SAP, ABAP had many advantages compared to Java in building WD. More over Java had many disadvantages when compared with ABAP.

With the advantage ABAP has, currently ABAP seems to be the future of WebDynpro.

View an animated story line of triangular love story between WD, ABAP and Java

Advantages/difference between ABAP and Java WD.

Comprehensive Comparison

Here is a valuable SAP Press book on Webdynpro ABAP.

Story of WebDynpro. Who is the hero? ABAP or Java ?

Here is the story of our heroine, WebDynpro. The story is about whom will the queen WebDynpro marry? Java or ABAP?

This question also decides the career path for several Webdynpro Java professionals. It might also open-up a new career path for ABAP professionals.

Story Starts
Java was WebDynpro's childhood friend. WebDynpro was born and grown with Java. WebDynpro was heavily influenced by Java, because of Java's stature. He was considered a hero in his group of programing languages. Java had also had a huge list of fans and marrying Java also meant that WebDynpro also would get those fans and stature. SAP, WebDynpro's parent also thought that Java is the right guy for WebDynpro, even though Java was from a different religion. Engagement was done and everyone thought that they would get married and live happily ever after.

Climax
SAP, WebDynpro's parent, had other plans. He found that there is another probable hero and more over he is from the same religion. There were plenty of advantages in marrying a guy belonging to the same religion in terms of similar customs, culture and better communications as a result.
So SAP introduces ABAP to WebDynpro and wants to see how their chemistry develop. The chemistry develops between ABAP and WebDynpro and WebDynpro gradually moves away from Java and maintains only friendly relations with him.

With Parent's strong backup and more compatible fiancee, it is clear that this relationship is going to go for long time to come.
Meanwhile Java was adopted by Oracle, SAP's rival thus diminishing any chances of future marriage between WebDynpro and Java. But till date WebDynpro keeps a friendly relationship with Java.

The story continues and let us see if there is any more twist in the tail.........