[30+] Java Web Dynpro Interview Questions and Answers

1. What is a View Assembly?

Ans:

A window explains the superset of all possible views that Web Dynpro application could require whilst run a specific component. The number of views visible at a any one time, however, will typically be only a subset of a number of views embedded within the window.

2. What is Face Less component?

Ans:

It is component with a zero views and zero windows. Such component is known as a “faceless” component and is useful when a complex unit of functionality need no direct user interaction needs to be encapsulated. A good example of a faceless component is creation of something called model component. This is not actually a particular Web Dynpro component type; rather it is a standard Web Dynpro component that has been written specifically for a task of interacting with a model object.

3. What are types of Controllers?

Ans:

In broad terms, SAP has explained in two categories of Web Dynpro controllers.

The difference between them is:

• A controller either Has visual interface, or Does not have visual interface.
• SAP has introduced this difference in order to keep a strict separation between those parts of a business application that display data and those parts of a business application that process data.

4. What are the Recursion Nodes?

Ans:

The recursion node is a special type of node used when a node hierarchy with the recursive structure needs to be created. This is needed when, for instance, a depth of the node hierarchy is not known a until runtime. Using a recursion node, and can declare that a particular node structure is replicated as child of itself. A good example here is if context needs to hold data in the same structure as a file system, containing a directories and subdirectories.

5. What is Empty View?

Ans:

There is a special type of view known as an empty view. This view need no manual implementation, neither is it possible to interact with it in any way other than invoking its a default inbound plug – show Empty View. If require one specific area of a view set to be empty, then should embed the empty view into a view area.

Can then treat this view just like any other view have written, except that calling its inbound a plug will cause the corresponding view area to be blanked out. If a view set has had no views manually embedded into a one of its view areas, then an empty view will be substituted automatically.

6. How does a Web Dynpro framework decide which particular views make up a current view assembly?

Ans:

• When an application is executed for a first time, only those views which have their default flag set to a true will belong to the first view assembly.
• Thereafter, user navigation will occurred and the view assembly will be composed of views that have been newly ,and those views that persist from a previous view assembly .
• Define a WebDynpro Controller.
• Controllers are active parts of a Web Dynpro component. In a design of Web Dynpro controllers, SAP has made a significant modification to a original MVC concept of controller.

7. If view set concept is not implemented in a Web Dynpro for ABAP, what options are there for reusing views?

Ans:

In both Web Dynpro for an ABAP and Java, there is specific UI Element called the View Container. This UI element, when added to view layout, acts as a container for the any other view. View Containers can be arranged in big variety of ways to achieve the desired layout on a screen.

The views that can be embedded into View Container an UI element are the following:

• Any view from a current component
• Any visual interface from the child Web Dynpro component
• An empty view

8. What is View Set?

Ans:

A view set is a visual framework that subdivides a window into predefined areas. Every subdivision of a view set is known as view area, and multiple views can be embedded into single View Area.

9. How is model-driven architecture implemented in a Web Dynpro framework?

Ans:

The model-driven approach helps developers to focus less on a coding and technology part and more on design part of application – “minimizing coding and also maximizing design”. Naturally, a primary focus of business application developers should be business logic and the technological implementation should not be distract them.

10. How can determine a Lifespan of custom controllers?

Ans:

The lifespan of a custom controller is found by a parameter setting made during a design time declaration. It can be a either “Framework Controlled” or a “On-demand”. If choose a “Framework Controlled”, then Web Dynpro framework will instantiate acustom controller when the component is instantiated. If however, can choose “On-demand”, then tWeb Dynpro developer must write the coding necessary to instantiate the custom controller.

11. Explain the Concept of a Lazy Data Access.

Ans:

The Web Dynpro framework has been built to follow a principle of Lazy Data Access. This means that processing need to generate data will not be invoked until the data is needed. When this principle is applied to architecture of the context, it means that unless there is attempt to access the data in the singleton child node, then even though a lead selection in the parent node has changed, the child node’s supply function will not be called.

12. Before a mapping relationship can be established, what is criteria must be met?

Ans:

There must be a suitable node available to act as the mapping origin

13. What Is a Purpose Of Garbage Collection In Java, And When Is It Used?

Ans:

The purpose of garbage collection is to identify and discard objects that are no longer required by a program so that their resources can be reclaimed and reused. A Java object is subject to a garbage collection when it becomes unreachable to program in which it is used.

14. What If The Main Method Is Declared As a Private?

Ans:

The program compiles properly but at a runtime, it will give “Main method not public.” message.

15. What If Write Static Public Void Instead Of Public Static Void?

Ans:

A Program compiles and runs properly.

16.What If Do Not Provide a String Array As The Argument To The Method?

Ans:

Program compiles but throws the runtime error “NoSuchMethodError”.

17. What Is a First Argument Of The String Array In Main Method?

Ans:

The String array is an empty. It does not has any elements. This is an unlike C/C++ where the first element by default is a program name.

18.How Can One Prove That The Array Is Not Null But Empty Using a One Line Of Code?

Ans:

Print args. length. It will print a 0. That means it is empty. But if it would have been null then it would have thrown the Null Pointer Exception on attempting to print args. length.

19.What Are the Checked And Unchecked Exception?

Ans:

A checked exception is some subclass of an Exception (or Exception itself), excluding a class Runtime Exception and its subclasses. Making an exception checked forces on client programmers to deal with the possibility that the exception will be thrown. eg, IOException thrown by a java.io.FileInputStream’s read() method· Unchecked exceptions is a Runtime Exception and any of its subclasses. Class Error and its subclasses also are be unchecked. With an unchecked exception, however, a compiler doesn’t force client programmers either to catch the exception or declare it in a throws a clause. Client programmers may not even know that exception could be thrown. eg, StringIndexOutOfBoundsException thrown by a String’s char At () method· Checked exceptions must be caught at a compile time. Runtime exceptions are do not need to be. Errors an often cannot be.

20.What Are Different Types Of a Inner Classes?

Ans:

Nested top-level classes, Member classes, Local classes, Anonymous classes Nested top-level classes- If declare a class within a class and specify a static modifier, the compiler treats a class just like any other top-level class. Any class outside declaring class accesses the nested class with the declaring class name acting similarly to the package. eg, outer. Inner. Top-level inner classes implicitly have access only to a static variables. There can also be an inner interfaces. These are of a nested top-level variety.

Member classes : Member inner classes are just like the other member methods and member variables and access to a member class is restricted, just like a methods and variables. This means public member class acts similarly to the nested top-level class. The primary difference between the member classes and nested top-level classes is that member classes have access to a specific instance of the enclosing class.

Local classes : Local classes are like a local variables, specific to a block of code. Their visibility is only within a block of their declaration. For the class to be useful beyond a declaration block, it would need to implement a publicly available interface. Because local classes are not be members, the modifiers public, protected, private, and static are not usable.

Anonymous classes : Anonymous inner classes are extend local inner classes one level further. As anonymous classes has no name, and cannot provide a constructor.

21.What Is Difference Between An Interface And An Abstract Class?

Ans:

An abstract class can have a instance methods that implement default behaviour. An Interface can only declare a constants and instance methods, but cannot be implement default behaviour and all the methods are implicitly abstract. Interface has all public members and has no implementation. An abstract class is class that may have a usual flavours of class members (private, protected, etc.), but has some abstract methods.

22. Describe a Synchronization In Respect To Multithreading?

Ans:

Concerning multithreading, synchronization is a capability to control the access of multiple threads to a shared resources. Without synchronization, one thread can change a shared variable while another thread is in a process of using or updating the same shared variable. This usually leads to a significant errors.

23.What Are the Pass By Reference And Pass By Value?

Ans:

Pass by Reference means passing a address itself rather thana passing the value. Pass by Value means passing a copy of value to be passed.

24. What Is a Hashmap And Map?

Ans:

Map is an Interface and Hashmap is a class that implements that.

25.Difference Between a Hashmap And Hashtable?

Ans:

The HashMap class is a roughly equivalent to a Hashtable, except that it is unsynchronized and permits nulls. (HashMap allows null values as key and value whereas a Hashtable doesn’t allow). HashMap does not guarantee that order of the map will remain constant over time. HashMap is an unsynchronized and Hashtable is synchronized.

26.Difference Between a Vector And Arraylist?

Ans:

Vector is a synchronized whereas an arraylist is not.

27.Difference Between a Swing And Awt?

Ans:

AWT are the heavy-weight components. Swings are the lightweight components. Hence swing works faster than a AWT.

28.What Is Difference Between A Constructor And A Method?

Ans:

A constructor is a member function of class that is used to create a objects of that class. It has a same name as the class itself, has no return type, and is invoked using as new operator. A method is an ordinary member function of class. It has its name, a return type (which may be void), and is invoked using a dot operator.

29.What Is Iterator?

Ans:

Some of the collection classes are provide traversal of their contents via Exceptions.Iterator interface. This interface allows to walk through a collection of objects, operating on every object in turn. Remember when using an Iterators that they contain a snapshot of collection at the time the Iterator was obtained; generally, it is not advisable to modify a collection itself while traversing an Iterator.

30.What Is Abstract Class?

Ans:

Abstract class must be an extended/subclassed (to be useful). It serves as template. An abstract class may not be an instantiated ,abstract class may contain a static data. Any class with an abstract method is an automatically abstract itself and must be declared as a such. A class may be declared abstract even if it have no abstract methods. This prevents it from the being instantiated.

31.What Is a Static In Java?

Ans:

Static means a one per class, not one for each object no matter how many instances of class might exist. This means that can use them without creating instance of a class. Static methods are implicitly final, because overriding is done based on type of a object, and static methods are attached to a class, not an object. A static method in superclass can be shadowed by the another static method in a subclass if the original method was not declared be final. However, can’t override a static method with the non-static method. In other words, can’t change a static method into an instance method in the subclass.

32. What Is a Final?

Ans:

A final class can’t be an extended ie., a final class may not be subclassed. A final method can’t be overridden when its class is be inherited. and can’t change value of a final variable (is a constant).

33.Are The Imports Checked For Validity At a Compile Time? E.g. Will Code Containing A Import Such As Java.lang.abcd Compile?

Ans:

Yes, the imports are checked for a semantic validity at compile time. The code containing a above line of an import will not compile. It will throw an error saying, cannot be resolve symbol

• symbol: class ABCD
• location: package io
• import java.io.ABCD;.

34. What Is Difference Between Declaring A Variable And Defining A Variable?

Ans:

In the declaration, just mention a type of the variable and its name. do not initialize it. But defining means a declaration + initialization. e.g String s; is just declaration while String s = new String (“abcd”), Or String s = “abcd”; are both the definitions.

35.Objects Are Passed By Value Or By Reference?

Ans:

Java only supports a pass by values. With objects, the object reference itself is passed by a value and so both original reference and parameter copy both refer to the same object.

36.What Is a Serialization?

Ans:

Serialization is a mechanism by which can save the state of an object by converting it to the byte stream.

37.How Do Serialize An Object To A File?

Ans:

The class whose instances are to be a serialized should implement interface Serializable. Then can pass the instance to the Object Output Stream which is connected to the file output stream. This will save a object to a file.

38. Which Methods Of Serializable Interface Should be Implement?

Ans:

The serializable interface is an empty; it does not contain of any methods. So, do not implement any methods.

39. What Is Common Usage Of Serialization?

Ans:

Whenever an object is to be sent over a network, objects need to be serialized. Moreover, if the state of object is to be saved, objects need to be serialized .

40.What Is an Externalizable Interface?

Ans:

Externalizable is an interface that contains a two methods read External and write External. These methods give can control over the serialization mechanism. Thus, if class implements this interface, and can customize the serialization process by an implementing these methods

41. What One Should Take Care Of a While Serializing The Object?

Ans:

One should make a sure that all the included objects are also be serializable. If any of objects is not serializable then it throws Not Serializable Exception.

42. What Happens To The Static Fields Of Class During Serialization?

Ans:

• Serialization ignores a static fields because they are not part of any state.
• Base class fields are only handled if a base class itself is serializable.
• Transient a fields.

43.What Are Different Ways To Handle Exceptions?

Ans:

• By wrapping a desired code in a try block followed by the catch block to catch the exceptions.
• List the desired exceptions in a throws clause of the method and let the caller of method handle those exceptions.

44. What Is The Basic Difference Between a 2 Approaches To Exception Handling? 1> Try-Catch Block And 2> Specifying The Candidate Exceptions In a Throws Clause? When Should Use Which Approach?

Ans:

In the first approach as a programmer of method, dealing with an exception. This is fine if are in the best position to decide what should be done in case of an exception. Whereas if it is not responsibility of the method to deal with its exceptions, then do not use this approach. In this case, use a second approach. In the second approach, forcing the caller of the method to catch an exceptions, that the method is likely to throw. This is often approach library creators use. They list the exception in a throws clause and we must catch them. Then will find the same approach throughout a java libraries we use.

45.Define a Webdynpro Controller?

Ans:

Controllers are the active parts of the Web Dynpro component. In a design of Web Dynpro controllers, SAP has made a significant modification to a original MVC concept of a controller.

46. Where can the list of limitations for a Web Dynpro ABAP be found?

Ans:

The list of currently applied list of limitations for a Web Dynpro ABAP can be found in a 1098009.

47. How do manage information for an end-users in Web Dynpro application?

Ans:

In a ABAP Workbench, can also create and show messages that contain information for an end-users of Dynpro application. These messages are displayed on a screen. These are user interactive messages that display a important information about Web Dynpro application.

48.Can create a Transaction code for a Web dynpro ABAP Application?

Ans:

Yes, can create a Transaction code for a web Dynpro application.

Please follow steps below:

• Go to SE93
• Create a Code
• Choose a last option and maintain values

49.Can please explain what is service call in a Web Dynpro ABAP ? What is it used for?

Ans:

The service call is a Wizard based tool that is used to call for any existing function module or methods of an existing class within the Web Dynpro component. Service call helps us to an automatically create context nodes and web Dynpro method as per the Function Module/Class method parameters.

50.What is differnce between a component controller and interface controller?

Ans:

Component controlle	Interface controller
A component controller is the global controller, when we declare data in a component controller then that data can be accessed by the all views and windows inside that component.	Interface controller is a type of controller which is responsible for a communicating with an external web Dynpro components.

51. What is difference a between node & attribute in Web Dynpro ABAP?

Ans:

Node is a collection of the attributes whereas Attributes are variables that are used to store a single value at time.

52.How many types of cardinality are in a web dynpro ABAP?

Ans:

There are two types of cardinality in a web dynpro ABAP.

• Collection cardinality
• Selection cardinality

53.What is importance of interface controller in a Web Dynpro ABAP?

Ans:

Interface controller is a type of controller which is responsible for the communicating with external web Dynpro components.

54. What is a context mapping ?

Ans:

Context mapping is a mapping of a various controller’s context

55.What is a purpose of interface view property?

Ans:

Interface view is created a whenever the window is created. It is useful because it creates a different Applications for a Component

56. Do have the option to use a Web Dynpro ABAP on BASIS upgrade 6.40 which contains a development objects of Web Dynpro ABAP?

Ans:

For upgrade a 6.40 the Web Dynpro ABAP is not available.

57.For which upgrade a Web Dynpro ABAP is available?

Ans:

The Web Dynpro ABAP is available for a NetWeaver 2004 upgrade 7.00.

58.While clicking to create roundtrip to the server when quickly clicking a several times in succession, a system creates yet another request, which generates short dump. Whereas while a clicking slowly or a once, no short dump occurs?

Ans:

The system activates a click protection before sending a page to the server. But it takes some milliseconds to activate this protection and during this period a above-mentioned problem may occur. There is no solution to this problem as a browser will take some time to activate the click protection. The click protection gets an executed at the beginning of a submit handling on the client.

59.The Web Dynpro application suddenly stops working correctly while working with the complex screens. Why this issue occurs?

Ans:

This issue occurs because of UI container elements are nested in a Web Dynpro views it will result in a more high nesting depth of the HTML rendering tag. Because of depth of approx 100, the browser stalls, as such deep hierarchies cannot be processed by it. Therefore to resolved this issue and must simplify the views by decreasing their nesting depth. There is no generic simplification provided by a Web Dynpro.

60.What Are System Fields? Explain?

Ans:

The ABAP system fields are active in all of ABAP programs. They are filled by a runtime environment, and can query their values in a program to find out particular states of a system. Although they are variables,then should not assign a values to them, since this may overwrite information that is important for a normal running of the program. However, there are some isolated cases in which may need to overwrite a system variable. For example, by assigning a new value to a field SY-LSIND, you can control navigation within details lists.

61.How will direct application to use HTTPS instead of HTTP?

Ans:

To use in the other Web Dynpro components.

62. How do introduce a line break for the UI element in any layout?

Ans:

Say if using a matrix layout, that will say Matrix Head data for an UI element for which need a line break.

63. How do read a parameters passed in a Web Dynpro URL?

Ans:

When create a web Dynpro application, and can see the link URL generated by a web Dynpro.

64.How will delete selected rows in a Table / ALV?

Ans:

Get a Table / ALV data in an internal table,Delete the row selected by a user from the internal table,Re-bind an internal table to the node bound to a Table/ALV.

65.Can run a Webdynpro Application in a background?

Ans:

It doesn’t make a sense to run a webdynpro application in a background because in that case, are beating the purpose of the MVC controller architecture for webdynpro. However, can build a logic to create background jobs from the Web Dynpro Application.

66. What is meaning of 0:1 cardinality of context node in a Web Dynpro application?

Ans:

It means that at a run time, no element or maximum one element can be an instantiated.

67. What Is Use Of Interactive Forms?

Ans:

create forms based on an Adobe software and can use it in context for a Web Dynpro user interfaces. And can integrate Adobe lifecycle development tools with the ABAP editor to ease the development of user interface. Interactive forms using a Adobe software allows to create efficient and simple development of UI elements.

68. What are init events and in what sequence they are triggered in a Web Dynpro?

Ans:

• WDDOINIT of a component Controller
• WDDOINIT of a window Controller
• WDDOINIT of a View Controller

69. What is purpose of garbage collection in a Java, and when is it used?

Ans:

The purpose of a garbage collection is to identify and discard objects that are no longer needed by program so that their resources can be reclaimed and reused. A Java object is subject to a garbage collection when it becomes unreachable to a program in which it is used.

70. What if main method is declared as private?

Ans:

The program compiles properly but at a runtime, it will give a “Main method not public.” message.

71 . What is the use of a SAP List Viewer in Web Dynpro?

Ans:

SAP List viewer is used to add ALV component and provides a flexible environment to display a lists and tabular structures. A standard output consists of header, toolbar, and an output table and the user can make settings add column display, aggregations, sorting options using additional dialog boxes.

72. what is the use of a Window Controller in a Web Dynpro?

Ans:

Window controller exists for every window and contains a method of the writing coding logic.

73. What are the Hook methods?

Ans:

Hook methods are the standard web Dynpro methods that are called at various scenarios in a web Dynpro lifecycle.

74. What is View Assembly?

Ans:

A window explains the superset of all possible views that a Web Dynpro application could need whilst run a particular component. The number of views visible at any one time however, will typically be only a subset of a number of views embedded within a window.

75. What is a View Set?

Ans:

A view set is visual framework that subdivides a window into predefined areas. Every subdivision of a view set is known as a view area, and multiple views can be embedded into single View Area.

The below preconfigured view sets are available:

• T layout 90o T layout 180o T layout 270o Grid layout of Tab strip.
• Every subdivision within the view set layout is known as view area.

76. What is a MVC in WebDynpro ABAP?

Ans:

Basically, WebDynpro follows a MVC M-Model (Business logic) V-View(Screen) C-Controller (Controls screen and Model)

77.What is a selection cardinality in WebDynpro ABAP?

Ans:

WebDynpro ABAP training in Bangalore specifies how many records can be selected from node.

78. Is it a true that each controller has its a own Context node?

Ans:

Yes, each controller has its a context, methods, and Events.

79.At design time, how do decide whether to declare a node in a Component Controller or the View Controller?

Ans:

This again depends on a requirement: If the node is going to be accessed in a multiple views, it should be declared at a Component Controller level. However, If the node is specific to the only one view, it can be explained in the View Controller. As the size of Webdynpro development grows, it starts from becoming complex and the need to explain attributes, nodes, methods, etc. at the Component Controller increases.

80.Can use a multiple layouts in one view?

Ans:

• Layouts can be assigned at a container level. For example, explain the layout for the view at the ROOTUIELEMENT container level.
• So if at all want to use a multiple layouts in one view, and can create multiple transparent containers and assign various layouts to them.

81.How do introduce a line break for UI element in any layout?

Ans:

Say if using a matrix layout, that will say Matrix Head data for the UI element for which need a line break.

82.Can call/launch one web Dynpro application from the another Webdynpro application?

Ans:

Yes, can launch a one Webdynpro application from the another Webdynpro application. First, should get an URL of the Web Dynpro component that want to launch, and second, call that an URL in an external window.

To get an URL of any web Dynpro component, can use the FM

• CALL METHOD cl_wd_utilities=>construct_wd_url
• EXPORTING application_name = ‘ZDEMO’
• IMPORTING out_absolute_url = str.

Once you get the URL in str, and can call this web Dynpro using ‘str’ and FM, create_external_window.

83.What is a Web Dynpro Phase model?

Ans:

• Whenever a roundtrip occurs from a client (browser) to the server, a sequence of the processing steps is executed. This sequence of processing steps in web Dynpro is called Phase Model’.
• Executing all of tasks in the phase model is a responsibility of the Web Dynpro framework.

84.How will delete a selected rows in a Table / ALV?

Ans:

• Get a Table / ALV data in an internal table.
• Delete a row selected by the user from an internal table.
• Re-bind the internal table to a node bound to Table/ALV.

85. Can run a Webdynpro Application in background?

Ans:

It doesn’t make sense to run a Webdynpro application in a background because in that case, and are beating the purpose of the MVC controller architecture for a Webdynpro. However, and can build a logic to create background jobs from the Web Dynpro Application.

86. How do read parameters passed in aWeb Dynpro URL?

Ans:

When create a web Dynpro application, and can see a link URL generated by web Dynpro.

87. Can pass a parameters in Webdynpro URL?

Ans:

Yes, can pass parameters in a Webdynpro URL and read them too in aWeb Dynpro component.

88. What is use of a Web Dynpro window?

Ans:

In Web Dynpro, the window is used to use a multiple views or view sets. A view can only be displayed when it is embedded in the view and a window always contain one or more views that are connected by a navigation links. Every window contains inbound and outbound plugs and they can be included in a navigation chain. Inbound plugs within a window lead from a outbound plug of a view to the embedding window. Just like all the other inbound plugs, they represent an event and thus call an event handler assigned to them.

89. Can create a multiple applications using a component in Web Dynpro?

Ans:

Yes for a component, can create any number of the applications.

90. Types of ABAP UI Technologies?

Ans:

Webdynpro for an ABAP, BSP

91. MVC Architecture Concepts and usage of a same in ABAP Webdynpro

Ans:

As per the MVC Architecture there is clear separation between a flow logic, view and the Business Logic. View holds all UI elements that are visible in a UI, Controllers have the flow logic. Controllers are of a various kind (Component Controller, View Controller, a window Controller). Business logic is held in a Model which is in the form of an Assistance class in webdynpro context.

92. Difference Between a View Container and the Transparent Container

Ans:

View Container	Transparent Container
View Container holds a views, there can be a multiple views assigned to the view container but only one view can be active(viewed) at time.	Transparent holds a webdynpro UI elements, A layout type can be an associated with it.

93. What does Model Class Consists of?

Ans:

Model Class is an Assitance class in webdynpro. It contains a Business logic in the form of methods, Global data & Constants in the form of Class Attributes. The Model class can be accessed in a webdynpro component using the attribute wd_assist->. Note: All visibility properties of the Classes are applicable when accessing a class using the object wd_assist.

94.What is an Assistance Class and How is it Instantiated in a Webdynpro?

Ans:

Assistance Class is a model class that would act as the data provider for a webdynpro component and it is instantiated by a webdynpro component during run time and no explicit instantiation is be required.

95. Design Patterns in a Webdynpro(GAF,OIF,QAF Etc)

Ans:

FPM Concepts in a Webdynpro

96. How do debug an web based Application (Could be from ABAP Webdynpro, BSP or CRM Web UI)?

Ans:

External break-points should be used to a debug web UI’s.

97. How do Navigate between a Views in Webdynpro?

Ans:

Navigation between Views is a through Plugs(Inbound and Outbound), How do build F4 Search Help in Webdynpro F4 help for an input field can be made available by an attaching the search help to a table field. Usage of standard help component of WDR_OVR. Creating a component for help and attaching it to a node element as a Freely programmed value help

98. How are Plugs(Inbound/Outbound) bounded in a Window?

Ans:

Plugs are created in a view and bounded in the window by using a drag-drop option in the window. view.

99. How do Control the visibility of a Webdynpro UI elements Programmatically?

Ans:

Create a context element of type like wdui_visibility and bind it to the visibility property of an UI element.

100. What is the use of an Interface views/nodes in Webdynpro?

Ans:

Interfaces nodes and views are created to use in the other webdynpro components.