[30+] Java Web Dynpro Interview Questions and Answers

Last updated on 14th Nov 2021, Blog, Interview Questions

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1. What is View Assembly?

Ans:

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

The subset of views rendered at any one time is known as the View Assembly. User interaction followed by subsequent navigation processing will frequently cause this subset of views to change with every server round-trip. The view assembly represents those views seen by the user on their client device after the completion of a particular server round trip.

2. What is the Face Less component?

Ans:

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

3. What are the types of Controllers?

Ans:

In broad terms, SAP has defined two categories of Web Dynpro controllers. The difference between them is simply this: A controller either Has a visual interface, or Does not have a visual interface.

SAP has introduced this difference in order to maintain a strict separation between those parts of the business application that display data (typically data consumers), and those parts of the business application that process data (typically data generators).

4. What are Recursion Nodes?

Ans:

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

5. What is an Empty View?

Ans:

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

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

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

Ans:

• When an application is executed for the first time, only those views which have their default flag set to true will belong to the first view assembly.
• Thereafter, user navigation will occur and the view assembly will be composed of those views that have been newly instantiated (on account of their inbound plugs being fired), and those views that persist from the previous view assembly (because no outbound navigation took place from them).
• Define WebDynpro Controller.
• Controllers are the active parts of a Web Dynpro component. In the design of Web Dynpro controllers, SAP has made a significant modification to the original MVC concept of a controller..

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

Ans:

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

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

• Any view from the current component
• Any visual interface from a child Web Dynpro component
• An empty view (supplied automatically by the Web Dynpro runtime).

8. What is a View Set?

Ans:

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

The following preconfigured view sets are available:

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

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

Ans:

Web Dynpro framework uses declarative programming techniques to create a meta-model of the application which is free from back-end and front-end programming languages. Rather the metadata is programming language-neutral and has information stored in XML format. It’s only during run-time that the rendering engine generates the code in HTML and javascript from this meta-model of the application. So the design part – which defines the UI and data flow between UI elements – is completely abstracted minimizing the coding (which is required only for implementing business logic).

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

10. How can you determine the Lifespan of custom controllers?

Ans:

• The lifespan of a custom controller is determined by a parameter setting made during the design time declaration. It can be either “Framework Controlled” or “On-demand”. If you choose “Framework Controlled”, then the Web Dynpro framework will instantiate the custom controller when the component is instantiated. If however, you choose “On-demand”, then the Web Dynpro developer must write the coding necessary to instantiate the custom controller.
• Each child component usage is instantiated with a unique name that must be defined at design time. During the lifespan of the parent component, a child component may only ever be instantiated once under a given name; however, should it be necessary, you may declare multiple usages of the same child component as long as you specify different user names.

11. Explain the Concept of Lazy Data Access.

Ans:

The Web Dynpro framework has been built to follow the principle of Lazy Data Access. This means that the processing required to generate data will not be invoked until the data is needed. When this principle is applied to the architecture of the context, it means that unless there is an attempt to access the data in a singleton child node, then even though the 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 criteria must be met?

Ans:

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

13. What Is The 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 needed by a program so that their resources can be reclaimed and reused. A Java object is subject to garbage collection when it becomes unreachable to the program in which it is used..

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

Ans:

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

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

Ans:

Program compiles and runs properly..

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

Ans:

Program compiles but throws a runtime error “NoSuchMethodError”..

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

Ans:

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

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

Ans:

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

19.What Are Checked And Unchecked Exception?

Ans:

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

20.What Are Different Types Of Inner Classes?

Ans:

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

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

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

Anonymous classes – Anonymous inner classes extend local inner classes one level further. As anonymous classes have no name, you cannot provide a constructor.

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

Ans:

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

22. Describe Synchronization In Respect To Multithreading?

Ans:

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

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

Ans:

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

24. What Is Hashmap And Map?

Ans:

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

25.Difference Between Hashmap And Hashtable?

Ans:

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

26.Difference Between Vector And Arraylist?

Ans:

Vector is synchronized whereas arraylist is not..

27.Difference Between Swing And Awt?

Ans:

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

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

Ans:

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

29.What Is An Iterator?

Ans:

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

30.What Is An Abstract Class?

Ans:

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

31.What Is Static In Java?

Ans:

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

32. What Is Final?

Ans:

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

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

Ans:

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

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

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

Ans:

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

35.Objects Are Passed By Value Or By Reference?

Ans:

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

36.What Is Serialization?

Ans:

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

37.How Do I Serialize An Object To A File?

Ans:

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

38. Which Methods Of Serializable Interface Should I Implement?

Ans:

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

39. What Is The Common Usage Of Serialization?

Ans:

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

40.What Is Externalizable Interface?

Ans:

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

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

Ans:

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

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

Ans:

There are three exceptions in which serialization does not necessarily read and write to the stream.

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

43.What Are The Different Ways To Handle Exceptions?

Ans:

There are two ways to handle exceptions:

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

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

Ans:

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

45.Define Webdynpro Controller?

Ans:

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

46.If The View Set Concept Is Not Implemented In Web Dynpro For Abap, What Options Are There For Reusing Views ?

Ans:

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

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

• Any view from the current component
• Any visual interface from a child Web Dynpro component
• An empty view (supplied automatically by the Web Dynpro runtime)

47.How Is Model-driven Architecture Implemented In Web Dynpro Framework ?

Ans:

Web Dynpro framework uses declarative programming techniques to create a meta-model of the application which is free from back-end and front-end programming languages. Rather the metadata is programming language-neutral and has information stored in XML format. It’s only during run-time that the rendering engine generates the code in HTML and javascript from this meta-model of the application. So the design part – which defines the UI and data flow between UI elements – is completely abstracted minimizing the coding (which is required only for implementing business logic).

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

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

Ans:

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

Please follow the steps below:

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

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

Ans:

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

50.What is the differnce between component controller and interface controller

Ans:

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

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

Ans:

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

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

Ans:

There are two types of cardinality in web dynpro ABAP.

• Collection cardinality
• Selection cardinality

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

Ans:

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

54. What is context mapping ?

Ans:

Context mapping is a mapping of different controller’s context

55.What is the purpose of interface view property?

Ans:

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

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

Ans:

For upgrade 6.40 the Web Dynpro ABAP is not available. see 751611 for more info.

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

Ans:

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

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

Ans:

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

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

Ans:

This issue occurs because the UI container elements are nested in Web Dynpro views (for example, six tabs within each other) it will result in a very high nesting depth of the HTML rendering tag. Because of a depth of approx 100, the browser stalls, as such deep hierarchies cannot be processed by it. Therefore to resolve this issue we must simplify the views by decreasing their nesting depth. There is no generic simplification provided by Web Dynpro.

60.What Are The System Fields? Explain?

Ans:

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

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

Ans:

To use in other Web Dynpro components.

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

Ans:

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

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

Ans:

First, let’s understand how a typical webdynpro application looks like:

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

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

Ans:

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

65.Can you run a Webdynpro Application in the background?

Ans:

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

So we have by now put a bunch of questions here. Let me know how do you find these questions. elementsn’t yet covered Web Dynpro component usage, ALV, Select Options, OVS, the coding part in web Dynpro, Web Dynpro enhancements, etc.

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

Ans:

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

67. What Is The Use Of Interactive Forms?

Ans:

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

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

Ans:

• WDDOINIT of component Controller
• WDDOINIT of window Controller
• WDDOINIT of View Controller.

69. What is the 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 needed by a program so that their resources can be reclaimed and reused. A Java object is subject to garbage collection when it becomes unreachable to the program in which it is used.

70. What if the main method is declared as private?

Ans:

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

71 . What if I write static public void instead of the public static void?

Ans:

The program compiles and runs properly.

72. What if I do not provide the String array as the argument to the method?

Ans:

Program compiles but throws a runtime error “NoSuchMethodError”.

73. What is the first argument of the String array in main method?

Ans:

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

74. How can one prove that the array is not null but empty using one line of code?

Ans:

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

75. What are Checked and Unchecked Exception?

Ans:

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

76. What is MVC in WebDynpro ABAP?

Ans:

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

77.What is selection cardinality in WebDynpro ABAP?

Ans:

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

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

Ans:

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

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

Ans:

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

80.Can you use multiple layouts in one view?

Ans:

Layouts can be assigned at the container level. For example, you define the layout for your view at the ROOTUIELEMENT container level.

So if at all you want to use multiple layouts in one view, you can create multiple transparent containers and assign different layouts to them.

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

Ans:

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

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

Ans:

Yes, you can launch one Webdynpro application from another Webdynpro application.

First, you should get the URL of the Web Dynpro component that you want to launch, and second, call that URL in an external window.

To get the URL of any web Dynpro component, you 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, you can call this web Dynpro using ‘str’ and FM, create_external_window.

83.What is the Web Dynpro Phase model?

Ans:

Whenever a roundtrip occurs from the client (browser) to the server, a sequence of processing steps is executed. This sequence of processing steps in web Dynpro is called the ‘Phase Model’.

Executing all the tasks in the phase model is the responsibility of the Web Dynpro framework.

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

Ans:

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

85. Can you run a Webdynpro Application in the background?

Ans:

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

So we have by now put a bunch of questions here. Let me know how do you find these questions.

We haven’t yet covered Web Dynpro component usage, ALV, Select Options, OVS, the coding part in web Dynpro, Web Dynpro enhancements, etc.

86. How do you read parameters passed in the Web Dynpro URL?

Ans:

First, let’s understand how a typical Webdynpro application looks like:

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

87. Can you pass parameters in a Webdynpro URL?

Ans:

Yes, you can pass parameters in Webdynpro URL and read them too in your Web Dynpro component.

88. What is the use of the Web Dynpro window?

Ans:

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

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

Ans:

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

90. Types of ABAP UI Technologies

Webdynpro for ABAP, BSP

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

Ans:

As per the MVC Architecture there is a clear separation between flow logic, view and the Business

Logic. View holds all the UI elements that are visible in the UI, Controllers have the flow logic.

Controllers are of a different kind (Component Controller, View Controller, a window Controller).

Business logic is held in the Model which is in the form of Assistance class in webdynpro context.

92. Difference Between the View Container and the Transparent Container

Ans:

View Container holds the views, there can be multiple views assigned to the view container but only

one view can be active(viewed) at a time. Transparent holds the webdynpro UI elements, A layout type can be associated with it.

93. What does a Model Class Consists of

Ans:

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

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

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

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

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Refer to the link :

FPM Concepts in Webdynpro

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

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

97. How do you Navigate between Views in Webdynpro

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

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

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

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

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

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

Ans:

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