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hi

Former Member
0 Kudos

hi all,

what is UI programming?

How prepared for UI?

send me any sample program...

reply me soon....

thanks,

s.suresh.

1 REPLY 1

Former Member
0 Kudos

hi,

Definition

Web Dynpro is the SAP NetWeaver programming model for user interfaces (UIs). The Web Dynpro model is based on the Model-View-Controller programming model, and has the following features that build on the classic dynpro model:

· Clear separation of business logic and display logic

· Uniform metamodel for all types of user interfaces

· Execution in a browser-based environment

· Extensive platform independence of interfaces

· Support of UI-pattern-based development of user interfaces

Structure

The metamodel concept

Web Dynpro provides support for the development of Web applications. You use specific tools to describe the properties of a Web Dynpro application in the form of Web Dynpro metadata. The necessary source code is then generated automatically and executed at runtime. In addition to the events offered by the framework, you can also define your own events for a Web Dynpro application. However, the event handling must always be programmed in separate source code areas which are executed automatically when the event is triggered at runtime.

In Web Dynpro, each user interface is always made up of the same basic elements. These elements of the metamodel can be statically declared using Web Dynpro tools.

It is also possible to implement elements of the metamodel technically using programming and to integrate them dynamically at runtime. Using these implementations, you can make any changes or enhancements to a user interface that has been created by declarative methods by generating new interface structures at runtime.

This means that you can combine declarative processes and the implementation of source code.

Platform independence

The metadata of a Web Dynpro application is independent of the platform on which the application is executed. This means that if the application is executed on a different platform after it has been created, the metadata can be transferred into the platform-specific environment. The new source code required for this platform is then generated. Only the source code that you have programmed yourself, for example in event handling, must be adapted to suit the new platform.

Web Dynpro client

A JavaScript-based client software application, the Client Side Framework (CSF), runs in the user’s browser. This means it is possible to send an abstract definition of the user interface to the browser based on HTTP, which is not evaluated until it reaches the browser, where it is evaluated by the CSF. The application data is sent separately. First, the CSF forms the complete application from the two separate parts, the user interface definition and the application data. This has the following advantages:

· Faster screen generation – updating screens is restricted to the changed area

· Full keyboard support and unrestricted user operation

· Reduction in the number of server requests through intelligent use of caches

Graphical development tools

To support this declarative concept, the SAP NetWeaver Developer Studio contains a range of Web Dynpro tools. You can therefore generate a large proportion of a Web Dynpro application using the tools provided, without having to create your own source code. This applies for the following parts of the application:

· Definition of the static or dynamic use of screen areas

· Data flow between the front end and back end

· Layout of the user interface

· Properties of user interface elements

The Web Dynpro tools also enable programming in customer areas of the generated source code. These areas are not changed if the source code is regenerated.

UI pattern-based creation of user interfaces

UI-pattern-based creation means that the uniform formation of user interfaces is supported. UI patterns normally only contain generic functions of the user interface (for example, a search function), and they prescribe the general appearance of the interface. This enables faster development of applications, which are then easier to use because of their uniform appearance.

You can use the Customizing functions supplied to adapt applications created using UI patterns.

Separation of business logic and display logic

Implementing Web Dynpro enables you to clearly separate business logic and display logic. A Web Dynpro application runs on the front end and has local or remote access to the back end system via a service. This means that the display logic is contained in the Web Dynpro application, while the business logic and the persistence of the business objects run in the back end system. The following possibilities are currently available for connecting Web Dynpro applications and the back end system:

· An interface generated using the SAP Java Connector, through which BAPIs of an SAP system can be called

· A self-generated interface

The source code required for connecting the Web Dynpro application can be generated from a UML definition of the Web Dynpro interface. A UML definition can be imported into the Web Dynpro tools as an XML file.

Conversion of the Model-View-Controller programming model

Every Web Dynpro application is modeled according to the Model-View-Controller programming model:

· The model forms the interface to the back end system and thus enables the Web Dynpro application access to data.

· The view is responsible for the representation of the data in the browser.

· The controller lies between the view and the model. The controller formats the model data to be displayed in the view, processes the user entries made by the user, and returns them to the model.

refer to the following site,

http://www.jax-magazine.com/itr/online_artikel/psecom,id,583,nodeid,147.html

please reward points if helpful,

shylaja

Edited by: shylaja puchala on Jan 15, 2008 3:22 AM