Contenido

BAdI Concept..........................................................................................................................................................2
Architecture...............................................................................................................................................................2
Definition and Implementation............................................................................................................................2
Object Types Involved.........................................................................................................................................3
Definition of BAdIs....................................................................................................................................................4
Use.........................................................................................................................................................................4
Instance Generation Mode......................................................................................................................................5
Definition................................................................................................................................................................5
Use.........................................................................................................................................................................5
Example................................................................................................................................................................. 5
The Multiple Use Property.......................................................................................................................................6
Definition................................................................................................................................................................6
Use.........................................................................................................................................................................6
Function Code and Screen Enhancements..........................................................................................................7
Use.........................................................................................................................................................................7
Features.................................................................................................................................................................7
BAdIs Embedded in the Enhancement Framework.............................................................................................8
Use.........................................................................................................................................................................8
The Problem with Large BAdI Interfaces...............................................................................................................9
The Problem..........................................................................................................................................................9
The Solution..........................................................................................................................................................9
Enhancement Spots and Enhancement Implementation............................................................................10
BAdIs – a Typical Use Case.................................................................................................................................13
Task...................................................................................................................................................................... 14
Execution.............................................................................................................................................................14
Explanation..........................................................................................................................................................14
Single-Use BAdI.....................................................................................................................................................15
Use Case 1: Single Customer Enhancement.................................................................................................15
Use Case 2: Multiple Customer Enhancements.............................................................................................15
Use Case 3: Use Existing Coding As Default.................................................................................................15
Multiple-Use BAdI...................................................................................................................................................16
Use Case 1: Multiple-Use BAdI........................................................................................................................16
Use Case 2: BAdI With Optional Functionality...............................................................................................16
Use Case 2: Encapsulating Data for Two BAdIs Within One Class............................................................17
Use Case 3: Encapsulating Data for Two BAdIs Within Several Compilation Units..................................18
Use Case 4: Inherit From a Default Class.......................................................................................................18
How to Use Filters..................................................................................................................................................18
Step-By-Step Examples with BAdIs.....................................................................................................................21
Building Your First BAdI.........................................................................................................................................21
Use Case.............................................................................................................................................................21
Building an Enhancement Spot........................................................................................................................21
Creating a BAdI...................................................................................................................................................21
The BAdI Interface..............................................................................................................................................22
Writing the Source Code....................................................................................................................................24
A Fallback Class.................................................................................................................................................24
How to Implement a BAdI......................................................................................................................................25
Create a Container for the Implementation.....................................................................................................25
The Implementing Class....................................................................................................................................27
Creating a Second BAdI Implementation........................................................................................................28
How to Use Filters..................................................................................................................................................29
Migrating Classic BAdIs.....................................................................................................................................31
Differences Between Classic and New BAdIs....................................................................................................31
Migrating BAdIs.......................................................................................................................................................32
Tips and Tricks........................................................................................................................................................32
Organization of BAdIs........................................................................................................................................32
Contexts for BAdIs..............................................................................................................................................32
Example...............................................................................................................................................................33
Working with Enhancements.............................................................................................................................33
Enhancement Builder..........................................................................................................................................34
BAdI Concept 
A BAdI within the Enhancement Framework is an enhancement option or an anchor point for an
object plug-in. A BAdI is an explicit enhancement option, which means that BAdIs are not
provided by the framework and have to be defined explicitly by the developer.
There are two different roles in the process of providing and implementing enhancement
options:
●      (Enhancement) option provider
The person who builds an enhancement option (functions like a “hook” to which others can
attach something). In general, the option provider is identical to the developer of a
development object who has to offer an explicit enhancement option (the so-called basic
development object). Typically, the developer of the basic development object is someone
working in the SAP core who anticipates that a customer or an industry solution might
want to add some code at a particular point. In this case, the option provider creates both
the development object to be enhanced and defines an enhancement option.
●      Implementer
The developer who implements an enhancement option. The implementer is not interested
in the details of an enhancement option, he or she just needs to know how to implement it.
The option provider has control on what the implementer does by defining the interface and
confining the implementer to the class that implements the BAdI.
The BAdI implementer cannot interfere with the basic program. It is assured that a BAdI
implementation can only change the parameters that were handed over to the BAdI. The
implementation of a method has a context of its own and the variables of the development object
using the BAdI are not even visible from inside the BAdI implementation.

Architecture 
Definition and Implementation
In the definitions for the Enhancement Framework, BAdIs are element definitions for
enhancement spots. They are processed directly in the Enhancement Builder.
BAdIs are the basis for object plug-ins that serve to enhance the functions in ABAP programs
without having to make modifications. BAdIs enable the creation of enhancement options in the
form of interfaces that can be appropriately implemented later on in the same system or an
external system.
As with all enhancements, BAdIs make a distinction between the definition and individual
implementations. The definition of a BAdI is usually created by SAP and, together with its
calling points in ABAP programs, it forms explicit enhancement options in such programs.
The definition of a BAdI contains a BAdI interface, a set of selection filters, and some settings
that affect runtime behaviour later on. A BAdI interface forms the entire interface or part of the
interface of an object plug-in.
A BAdI implementation is the term used in the Enhancement Framework for an enhancement
implementation element. A BAdI implementation consists of a BAdI implementation class that
implements the BAdI interface, and of a condition imposed on the filters specified in the BAdI
definition. These can be used to select the BAdI implementation.
The calling points of a BAdI are defined through the ABAP statements GET BADIand CALL
BADI, which – in the definition world of the Enhancement Framework – form the enhancement
spot element calls of the explicit enhancement option.
For more information about BAdI definitions, see Definition of BAdIs.
Object Types Involved
In keeping with design patterns, the command GET BADI corresponds to the call for an
abstract factory. It returns – depending on the filter values and a context – an instance of a proxy
object. The static constellation of the interfaces and classes involved is displayed in the
following UML diagram.

 
The BAdI has the name badi_name. The class shown here with the same name is a BAdI class,
which is created during the definition of a BAdI in the Enhancement Builder as the final
subclass of the abstract global class cl_badi_base. The BAdI class is the template for the BAdI
object, and does not play any visible role (with the exception of the namespace).
The name of the BAdI interface for which badi_name is defined is if_intf and contains the
predefined tag interface if_badi_interface. The BAdI interface must not contain any variable
attributes. If the BAdI can be used on a multiple basis, it must not contain any methods
with exporting or returning parameters. The methods of a BAdI interface are called BAdI
methods.
The BAdI implementation classes cl_imp1, ... , cl_impn also implement the BAdI
interface if_intf. The abstract class cl_abstract_imp displayed here is only for demonstration
purposes since, in contrast to the classical BAdIs, there are no limitations with regard to the
classes to be implemented provided they implement the BAdI interface only. A BAdI
implementation class can even implement two different BAdI interfaces. This makes it possible
when defining BAdIs, for example, to create partial implementations in the form of (abstract)
BAdI implementation classes from which the actual BAdI implementation classes inherit.

The BAdI class is not a BAdI implementation class and does not really implement the
BAdI interface, but merely contains references to the actual object plug-ins (objects
of BAdI implementation classes).

The architecture of BAdIs can be viewed also in relation to another design pattern,
known as the parameterized event handler. Here, the BAdI implementation classes
play the role ofobservers that automatically register at GET BADI for the
appropriate BAdI object. The BAdI object takes on the role of subject, and method
calls with CALL BADI correspond to a N

Definition of BAdIs 
Use
When you define a BAdI, you must specify a name, a BAdI interface as the interface for the
enhancement option, and the required filters.
The name of a BAdI is in the same namespace as data types from the ABAP Dictionary, global
classes, or interfaces. It is recommended that you use suitable prefixes, such as “BADI_”.
A filter consists of a filter name and a data type (integer, string, and so on).
In addition, you also define BAdI properties that are relevant at the runtime of a program with
the appropriate statements GET BADI and CALL BADI. For more information, see Instance
Generation Mode and Multiple Use.
Other properties that can be assigned to a BAdI include:
●      An optional fallback BAdI implementation class. This option is used if no BAdI
implementation with suitable filter conditions and no standard implementation is found.
●      Whether the BAdI is internal or not.

An internal BAdI must only be implemented by SAP and is not visible outside of
SAP.
●      Whether the BAdI is a function code or screen enhancement.
A BAdI that is defined as a function code enhancement must not have any filters, must not be
defined for multiple use, or assigned to any switch. It may contain methods that are independent
of the actual function code enhancement.
A BAdI that is defined as a screen enhancement must be defined in the instance generation
mode for the reused instantiation and must not be defined for multiple use. It may contain BAdI
methods that can be used to fill or evaluate the screen fields of the respective subscreens.

Instance Generation Mode 

Definition
This property controls the instantiation of the object plug-ins during execution of the
statement GET BADI. The following are possible specifications:
●      Newly created instantiation
●      Reused instantiation
●      Context-dependent instantiation
Use
The first two specifications define context-free BAdIs. In the case of the newly created
instantiation, new object plug-ins are created at each execution of the statement GET BADI. In
the case of the reused instantiation, an object plug-in that was used once in the current internal
mode is reused – if it is required more than once.
In the case of context-dependent instantiation, you need to specify a context for GET BADI.
This context controls the instantiation. Only one object plug-in is created for each context and
implementing class. Each time there is another GET BADI with the same context, it is reused. A
context is an instance of a class that implements the tag interface if_badi_context. The
specification takes place in the form of a reference to such an instance.

If object plug-ins are to get reusable data, only specifications 1 and 2 are allowed.
Example
The figures below show the situation for context-free BAdIs, after two statements following
each other:
GET BADI bd1.
GET BADI bd2.
The upper rectangles represent the BAdI objects. The broken-line arrows show which object
plug-ins are referenced by the BAdI objects, whereby the case of two suitable BAdI
implementation classes cl_imp1 and cl_imp2 is demonstrated.
Figure 1 shows the newly created instantiation. Each time a BAdI object is created, new object
plug-ins are created – first imp1 and imp2, then imp3 and imp4.
Figure 1
Figure 2 shows the reused instantiation. For each BAdI implementation class, only one instance
is created. All BAdI objects reference the same instance, irrespective of where (in internal
mode) and how the BAdI object is called.
Figure 2

The Multiple Use Property 

Definition
This property defines whether, during the initialization of a BAdI object using GET BADI, just
one implementation needs to be selected through the specified filter values, or whether an
arbitrary number of implementations (or no implementation at all) can be selected.
If more than one implementation is selected at GET BADI for a BAdI provided for single use,
the exception cx_badi_multiply_implemented is triggered. If no implementation is found, the
exception cx_badi_not_implemented is triggered.
Use
You can define whether a BAdI is to be provided for single or multiple use. In the standard
version, a BAdI is provided for single use, but a multiple use can also be selected.
In the case of a multiple use, there is a general restriction – in addition to the general restriction
regarding variable attributes – that the BAdI methods must not have
any EXPORTING or RETURNING parameters. The reason for this is that if you have a call
with CALL BADI, the methods of all the object plug-ins referenced by the BAdI object are
called and that there is no definition regarding from which of the implementations a returned
value will actually come. CHANGING parameters, on the other hand, are allowed since these
are changed by all the calling methods, one after the other, so that a method can also access the
parameter changed in a previous method.

Function Code and Screen Enhancements 

Use
The main use of BAdIs is to enhance ABAP programs using object plug-ins. For reasons of
compatibility, and to be able to use the classic means for designing a user interface in an ABAP-
based SAP system (GUI status and screens,) menu enhancements and screen enhancements were
adopted almost unchanged from the  classic BAdIs into the BAdIs of the new enhancement
concept. These enhancements represent a concept that is independent of enhancements through
object plug-ins and they are not supported using special ABAP statements.
Features
Function Code Enhancements
Menu enhancements have been adopted under the new name “Function Code Enhancements“,
whereby the classic concept has been kept in its entirety. The use of the ABAP statements GET
BADI und CALL BADI is not necessary. The runtime environment inserts the implementation
of a function code enhancement automatically during program regeneration.
Screen Enhancements
In the case of screen enhancements, the class concept has been adopted – with the following
exceptions:
●      The previous call to the
method CL_EXITHANDLER=>GET_PROG_AND_DYNP_FOR_SUBSCR, has been
replaced by the
call CL_ENH_BADI_RUNTIME_FUNCTIONS=>GET_PROG_AND_DYNP_FOR_SU
BSCRwith the same interface.
●      The methods PUT_DATA_TO_SCREEN and GET_DATA_FROM_SCREEN will no
longer be generated. You can create your own BAdI methods for data transport and call
them using CALL BADI.
●      You no longer need to call
the CL_EXITHANDLER=>SET_INSTANCE_FOR_SUBSCREENS andCL_EXITHAN
DLER=>GET_INSTANCE_FOR_SUBSCREENS methods. These methods are now
unnecessary as they only place the BAdI reference in a temporary storage.
SET_INSTANCE_FOR_SUBSCREENS is no longer necessary.
GET_INSTANCE_FOR_SUBSCREENS can, if necessary, be replaced by GET BADI.

BAdIs Embedded in the Enhancement Framework 

Use
The following figure shows the basic idea behind the implementation of a BAdI. You have one
BAdI definition and many implementations that may implement the same BAdI:
The definition of BAdIs is managed by enhancement spots. A simple enhancement spot for
BAdIs can contain several BAdI definitions as enhancement spot element definitions. BAdIs
that would otherwise be spread out in the system can be grouped together semantically.
This structuring is mirrored on the implementation side through the enhancement
implementations. A BAdI can be implemented by several BAdI implementations that are
managed by enhancement implementations. A simple enhancement implementation for object
plug-ins can contain several BAdI implementations of an enhancement spot as enhancement
implementation elements and can implement a BAdI multiple times. Therefore, several
enhancement implementations can be assigned to one enhancement spot.

A BAdI is always assigned to the same package, like the enhancement spot, to which it
belongs.
Example
The structuring features of BAdIs in enhancement spots can be of a technical or a subject nature.
If, in the definition of several BAdIs, you have the provision that they are to be used in the
same context (this is a feature known only by the person who defines the BAdIs), they must be
used by the same simple enhancement spot.
From a subject point of view, all BAdIs must then be grouped together by affiliation to
functional units – for example, payroll – in combined enhancement spots.

The Problem with Large BAdI Interfaces 

The Problem
Suppose you are faced with a large BAdI that has 50 methods (see the figure below). Of course,
this does not look like a BAdI that was designed adhering to the principles of good object-
oriented design, but you may still ask what is bad about such a BAdI:

Assume that in many solutions only the first three methods are needed, the others are known as
optional methods, which are only used by some customers in their system. Nevertheless, an
implementation of this BAdI has to implement all methods. A common result will be that the
first three methods get a real implementation while the rest get an empty implementation.
Now you are faced with a problem. When the BAdI definition is modified for some reason or
when there is an upgrade, in the SPAU_ENH you have to touch also the 47 methods that are
empty. So you spend your time on some work that is not necessary in any way.
The Solution
The solution to this problem is not to put the methods you need and optional methods in one
BAdI, but to tailor small BAdIs containing only the methods that are needed by a group of
customers. Of course, this does not mean you should put all methods you need in one large
BAdI if you need them for one IS. When designing a BAdI, you should adhere to the principles
of good object-oriented design. Do not define gigantic BAdIs, but small ones tailored for
definite problems or even parts of a problem. In any case, keep your BAdIs small, not as a
means in itself, but to have manageable BAdIs that do not force those who implement the BAdI
to write empty implementations. The figure below shows how you separate the methods:

When implementing a BAdI, you have to implement all its methods. This is a
consequence of the fact that a BAdI defines an interface, and interfaces have to be
implemented completely. Syntactically, there is no such thing as partially
implementing an interface.
How to Group the Small BAdIs
When designing small BAdIs, you can face a problem caused by the fact that the BAdIs are
small. Of course, you will get a higher number of BAdIs and a huge mass of BAdIs in the same
namespace, and this could soon lead to a disorganized mess.
To prevent this, you need containers in which you put the BAdIs. And this is, where the (simple)
enhancement spot is used. As for all the other enhancement types, this spot can be used as a
container for BAdI definitions. Of course, the BAdIs are still in the same namespace, but they
are structured in larger units, that is, the enhancement spots. Therefore they are easier to handle.
The following figure shows how you use containers:
Enhancement Spots and Enhancement Implementation 
●      The use of implementations that serve as containers.
On the right side of the figure below you have (simple) enhancement implementations
which serve as containers for the BAdI implementations.

        The use of packages.

It is the (simple) enhancement implementation to which a BAdI implementation belongs
that determines the package assignment of this BAdI.
The figure below presents a scenario in which BAdI implementations in the same (simple)
enhancement implementation belong to the same package, while BAdI implementations in
the different (simple) enhancement implementations may belong to different packages.
        The use of containers.
The switches with which you can switch the BAdI implementations are assigned to
packages. This means that you have to put BAdI implementations which must be switched
differently in different (simple) enhancement implementations. So, one reason why you
have containers on the implementation side is the fact that you need a unit that comprises
implementations which should be switched together.
Of course, this is not the only principle by which the (simple) enhancement
implementations can be designed. Other principles are: build manageable (simple)
enhancement implementations, and take project or other organizational issues into account.

        The figure below presents a resulting picture again, which now is no longer simplified.
The two yellow lines show something which might not happen often. Of course, you can
have many implementations of one BAdI in one (simple) enhancement implementation.
You need this if you need different classes as implementations that can be switched
together and, of course, your BAdI can be so defined that it can have multiple instances.
In case you want to cover different filter values with different implementations using the
same class, it is better to take only one implementation and to use a disjunction of filter
values for this implementation.
 In most cases, you have only one BAdI implementation in one (simple) enhancement
implementation, if you want to switch the implementation separately. Just think of the
cases in which you have a BAdI which must have exactly one implementation (a single use
BAdI).

        The figure below illustrates the fact that a (simple) enhancement implementation belongs
uniquely to a (simple) enhancement spot. One (simple) enhancement implementation
cannot contain BAdI implementations that are assigned to different (simple) enhancement
spots.

        The real-life example.

In real life programming you may have the units on the definition side tailored according to
the parts of a solution. The implementation side contains units, which are designed
according to one IS: IS_OIL. The smaller units mirror the organization on the definition
side.
The idea behind all these containers is to support organization and later search for
enhancement possibilities with a convincing nested structure. But you can only take full
 advantage of this structure if one prerequisite is fulfilled, the different containers must have
meaningful names and must be thoroughly documented.
If this is the case, you can use the Enhancement Browser (transaction SPAU_ENH) in
SE80 for the business part you want to enhance and search for a BAdI which you can
enhance for your purposes.

BAdIs – a Typical Use Case 

This example explains the enhancement technique through BAdIs.
Task
Country-specific validity tests are to be executed upon completion of an order in ERP. The
interface of this validity test is to be specified using the interface if_check_validity. The current
country is available in a field called cntry.
A suitable BAdI enhancement option consists of two parts:
1. 1.      Depending on the current country, an object (or even several objects) must be supplied
       

that implements the if_check_validity interface.

2.        2.      The appropriate methods of this object (or several objects) are called, and the result of
this validity test is used again in the ERP coding.
It is very important to ensure that the order processing itself predefines the specification of
the if_check_validity interface and its contract. The contract contains rules for the interface of
the BAdI. That is, which values may be passed to the methods, which values are expected back,
and what the return values mean.
In other systems that are based on ERP, a country-specific implementation can/must be provided
in accordance with the contract.
Execution
The two parts of an enhancement option described above are implemented using the following
ABAP statements:
●      GET BADI – for getting the BADI handle
●      CALL BADI – for calling interface methods
You might have a BAdI definition created in ERP with the name badi_check_validity. This
definition can have a method check_validity with an input parameter data that verifies the
validity of the order day and the country filter of the BAdIs which has the name country. In this
case, the enhancement option can look as follows:
DATA bd TYPE REF TO badi_check_validity.
GET BADI bd FILTERS country = cntry.
CALL BADI bd->check_validity EXPORTING data = ...
Explanation
The code fragment shows that the BAdI is addressed in an ABAP program through a reference
variable of the type REF TO badi_check_validity. An object that points to such a reference
variable is called a BAdI handle. BAdI names belong to the same namespace as all global
objects and data types.
The statement GET BADI searches in the repository for all currently activated implementations
of the BAdIs and chooses those that are defined for the filter value in cntry. These are
instantiated and are referenced by the BAdI handle created in the statement. In the following
statement, CALL BADI, the method call is automatically passed to the actual BAdI
implementation instances referenced by the BAdI handle.
 

Single-Use BAdI 
Use Case 1: Single Customer Enhancement
The normal customer enhancement is a BAdI without a filter which is called once. No state has
to be kept, so you can use static methods. Such a BAdI is defined in the core or an industry
solution and is implemented by a customer.
If the BAdI is a single-use BAdI, that is, it requires exactly one implementation, a default class
must be provided by SAP. Otherwise, the GET BADI will raise an exception if this statement is
executed before the customer has inserted his or her implementation.

An example of such a BAdI is a BAdI used for calculation.

Use Case 2: Multiple Customer Enhancements
This case is almost the same as use case 1, but with one important difference: different countries
have different implementations.

A calculation rule that depends on the country. It has default implementations

for Europe, Asiaand America and a default class for the rest of the world.
The example gives a good illustration of what default implementations are good for: Whenever a
specific implementation for a country is added, it is chosen with the respective filter value, the
default implementation is selected if the country is in Europe, Asia, or America. Otherwise the
default class handles things.
 Only default implementations can be overridden by more specific implementations.
Use Case 3: Use Existing Coding As Default
Sometimes you might have a piece of code which cannot be easily re-written in object-oriented
style. You can use this code in combination with a BAdI. One prerequisite is to use a single-use
BAdI with exactly one implementation. If there is none, you get the exception CX_BADI_
NOT_IMPLEMENTED. If you put the procedural code you want to reuse in the
respective CATCH clause, this code is only executed if the BAdI has no active implementation
selected. This code works like a default implementation.
If there are many implementations when you need exactly one, this is a more severe mistake and
the handling of this exception must return in the call hierarchy to a point where the current
process is continued with the next step that can do without the result of the calculation.

You have an existing report with procedural coding. You want to use some parts of
this report that cannot easily be transformed into a class.
Let the already existing code cover the default in case no BAdI implementation fits.
You accomplish this by using a TRY-ENDTRY construct and putting the procedural
code you want to reuse in the CATCH construct:
TRY
   GET BADI
   CALL BADI
   CATCH cx_badi_multiply_implemented.
      *Go somewhere up in the call hierarchy
   CATCH CX_BADI_NOT_IMPLEMENTED.     
      *Your code that must be reused
ENDTRY
 

Multiple-Use BAdI 
Use Case 1: Multiple-Use BAdI
You use a multiple-use BAdI with static methods if no data is kept and many implementations
make sense. For example, you can write defined results specified in the interface to different
destinations.

badi_additional_export
Export the book entry to additional destination(s) at the end of a book entry.
*Some_Code
*End of program
 CALL BADI badi_additional->export
The result of this example is:
 ●        Implementation1: Export to XML file
 ●        Implementation2: Export to sequential file
 ●        Implementation3: Export to external file
Use Case 2: BAdI With Optional Functionality
In the example figure below, the methods method_a and method_b have to be put into one
BAdI. All the optional methods are put in another BAdI:

Never put
mandatory and optional methods for a given solution or customer in one BAdI.

A large number of empty implementations indicates that your BAdI is too large.
        If there are many empty methods that are often not implemented, divide the BAdI.
        A design which leads to empty implementations of methods is a poor design: You will
have unnecessary work with empty methods if there are any changes to the BAdI.
        Instead of leaving optional methods empty, define them in different BAdIs.
        Adding new smaller BAdIs instead of modifying large BAdIs to reduce the effort for
implementation during import or upgrade.
Use Case 2: Encapsulating Data for Two BAdIs Within One Class
Sometimes you have two BAdIs that have to work on the same encapsulated data. An example
can be a BAdI that manages some data and writes it to the database and a BAdI that reads this
data.
If you have a class that implements the interfaces of both BAdIs, this class is selected as the
implementation for both selections. If you pass the same context object in both cases, you get
the same implementation because the class mentioned implements both interfaces. Because of
the same context object you get also the same the same instance.

GET BADI bd1 CONTEXT me

CALL METHOD bd1->meth
and
GET BADI bd2 CONTEXT me
CALL METHOD bd2->meth
If the BAdIs are instantiated from within the same context-object (which implements
the interface if_badi_context), you work with the same implementation and the same
instance. This implementation implements the interfaces of both BAdIs.
Use Case 3: Encapsulating Data for Two BAdIs Within Several Compilation Units
If you want to encapsulate data for two BAdIs that are called in different compilation units, you
need an additional context object, which is accessible from both compilation units.

GET BADI bd1 CONTEXT mycontext  "(some context given by a global

factory class)
CALL METHOD bd1->meth
and
GET BADI bd2 CONTEXT mycontext  "(some context given by a global
factory class)
CALL METHOD bd2->meth
In this case you need a separate context object. Both positions where the GET
BADI occurs must be able to reach the same factory class. Both BAdI calls will yield
calls to the same instance of class X. In addition, it is possible to share data between
BAdIs.
This technique allows small and simple BAdI definitions.
Use Case 4: Inherit From a Default Class
When you define a default class also as an example class, the one who implements the BAdI can
easily inherit from this class. This is a very comfortable way of redefining just the methods that
must be different from the example or the default class in your implementation.
 
 

How to Use Filters 

Recalling from the previous step (How to Implement a BAdI), you need a way to select between
different BAdI implementations. This is where you need the BAdI filter.
What you need is to change the BAdI definition. You can define one or many filters for a BAdI.
For the purpose of this example, you create only one filter. Therefore, in this step you define the
filter in the BAdI definition, determine filter values for the respective BAdI implementation, and
use the filter in the instantiation of the BAdI handle.

When modifying your example you do not take into account the differentiation
between the BAdI provider and the implementer. In real life it is the BAdI provider
who defines a BAdI with a filter or adds a filter to an existing BAdI. It is also part of
this role to use the filter condition to select the respective BAdI implementation in the
ABAP code. It is the implementer who determines the filter value(s) or an interval for
one or many BAdI implementations. For more information about the different roles,
see BAdIs Concept.
       1.      Navigate to your enhancement spot and open the Enh. Spot Element Definition tab that
shows a list of all the enhancement elements of the spot.
       2.      Switch to a change mode, select your BAdI in the list, and choose the Filter icon from the

toolbar above.
The following dialog appears, where you fill in the corresponding fields:

        3.      Confirm the entries.

The filter is now visible as a property below the BAdI.
4.      Activate the enhancement spot, double-click on the implementation and navigate to the
       

respective BAdI implementation by double-clicking the respective row in the table of BAdI
implementations.
5.      Switch to change mode, double -click the triangle in front of the BAdI implementation in the tree and then
double-click on the filter icon below.
6.      On the next screen, select the Combination icon.
7.      Select Country as the filter and confirm
8.      Double-click on the row below Combination 1.

A new dialog opens:

 
       9.      Activate
the (simple) enhancement implementation and navigate back to the spot.
The other implementation, that is the one for USA, also needs the respective filter value. So you go to the respective
(simple) enhancement implementation and change the BAdI implementation in the same way as you just did above.
The respective filter value for this country is 'US'.
   10.      Return to your program and adapt it to the modified BAdI. Running the syntax check shows you that you need

to have a filter parameter in the GET BADI command if the BAdI you try to instantiate is defined with a filter. The
required addition to the GET BADI command is FILTERS. It is after this keyword that you insert the name of the
BAdI filter and a value the filter is compared to. You also have to take care that an appropriate value can be passed to
the GET BADI routine:

REPORT  Z_DEMO_ENH.
parameters: ctry(2) type c.
DATA: handle TYPE REF TO z_badi_calc_vat,
sum TYPE p,
 vat TYPE p,
percent TYPE p.
sum = 50.
GET BADI handle FILTERS Country = ctry.
CALL BADI handle->get_vat
  EXPORTING im_amount = sum
  IMPORTING ex_amount_vat = vat
         ex_percent_vat = percent.
WRITE: 'percentage:', percent, 'VAT:' ,vat.
If you pass GB to the parameter ctry, you get a VAT rate of 16.5 percent. If the value of
the parameter ctry is US, the VAT rate is 4 percent. When the parameter ctry has any other
value, you still get a calculated value for the data field percent. This is because you have
defined a fallback class for your BAdI. The fallback class is not only selected if no BAdI
implementation is available, but also if none of the existing BAdI implementations meets
the filter conditions in the GET BADI command. Accordingly, you get a VAT rate of 20
percent, which is the VAT rate you have implemented in the method get_vat in the fallback
class.
 

Step-By-Step Examples with BAdIs  

This section presents several step-by-step examples that aim to help you easily navigate and
work with BAdIs in the Enhancement Builder:
3.        1.      Building Your First BAdI
4.        2.      How to Implement a BAdI

5.        3.      How to Use Filters

Building Your First BAdI 

Use Case
A developer needs to calculate the VAT of different ledger entries. The entries have to be passed
to a method that calculates and returns the VAT. Since the developer does not know what the
VAT in a specific country is, he or she defines a BAdI badi_vat with the method get_vat. This
method must return the VAT for a particular value that is passed to the method get_vat.
Building an Enhancement Spot
The first thing you need when creating a BAdI is a container for the BAdI. For that you need to
create a (simple) enhancement spot. This is the container in which you develop your BAdI.
       1.      Go to the ABAP Workbench (SE80) and navigate to your local objects.
       2.      In the context menu of the local objects folder,

choose Create → Enhancement → Enhancement Spot.
 A dialog appears.
        3.      Enter a name and a short text description for the enhancement spot.
Creating a BAdI
1.      To create a BAdI within the new enhancement spot, choose
       

the Create BAdI pushbutton on the left, as shown in the figure below:

2.      In the dialog window that appears, enter the BAdI name z_badi_calc_vat and a short
       

description.
You now have a BAdI in your enhancement spot.
3.      Deselect the Multiple Use option because for the current calculation you need a single-
       

use BAdI:

The BAdI Interface

Up to now, you still do not have a BAdI. You need an interface where you can define the
methods which determine what you can do with your BAdI.
       1.      Choose the arrow in front of the BAdI name.
       2.      Double-click on the Interface icon.
 Enter a name for the interface. You can choose an existing name or create a new one.

        3.      Choose the Change pushbutton.

This leads you to the Class Builder where you can create the methods you need for your
BAdI. You simply need to type in the name of the method get_vat and enter the parameters
you need.

A BAdI interface has to implement the interface if_badi_interface. But if you create a

BAdI interface in the way shown above, this marker interface is already integrated in
the BAdI interface.

        4.      Determine the parameters of the method:

        5.      Save and activate the interface and the spot.

By completing the steps above, you have created an enhancement spot and a BAdI with an
interface. The interface has one method so far.
However, just building a BAdI is not enough as it does not do anything. You need a BAdI
instance and this instance must be called somewhere in the code. Since the BAdI only defines an
interface, you need a class that implements this interface.
 A BAdI definition is the place to insert an object plug-in that does something at
runtime. You still need an object that is plugged in to get something done.
Writing the Source Code
Now you need to write some ABAP code to use the BAdI. You need a variable that can refer to
the BAdI and some variables that are given as actual parameters to the BAdI method.
Next, you need to create a handle for that BAdI and call the BAdI method get_vat. The
respective commands are GET BADI and CALL BADI.
DATA: handle TYPE REF TO z_badi_calc_vat,
sum TYPE p,
vat TYPE p,
percent TYPE p.
sum = 50.
GET BADI handle.
CALL BADI handle->get_vat
EXPORTING im_amount = sum
IMPORTING ex_amount_vat = vat
         ex_percent_vat = percent.
WRITE: 'percentage:', percent, 'VAT:', vat.
A Fallback Class
If you run the program at this stage, it dumps. This is because it is mandatory to have exactly
one active implementation for a single-use BAdI. You can handle this error by catching the
respective exception cx_badi_not_implemented.
The better solution is to use a fallback class. This class is used if there is no active BAdI
implementation.
The GET BADI command returns a handle to an instance of the fallback class and the
respective CALL BADIcalls the methods of the fallback class instance. As soon as there is an
active BAdI implementation, the fallback class is no longer used at runtime.
Using a fallback class serves two functions at once:
●      The program runs with a single-use BAdI without throwing an exception.
●      It is guaranteed that the fallback class is not used any more as soon as a BAdI
implementation is supplied. The fallback class is selected conditionally. This is important
because in most cases the BAdI provider does not know the details of some process. This
is why a BAdI is used.
To add a fallback class, proceed as follows:
1.      Select the Call fallback class if no implementation is executed option and enter a name for
       

the class:
         2.      Choose Change to go back to the Class Builder.
The respective method of the BAdI interface is already automatically defined. You only have
to implement it:
DATA: percent TYPE p VALUE 20.
ex_amount_vat = im_amount * percent / 100.
ex_percent_vat = percent.
       3.      Save and activate the class.
       4.      Navigate back to the enhancement spot and activate it.

       5.      Run the program.

The result should be:

percentage: 20 VAT: 10.
Next step is: How to Implement a BAdI and Use a Filter

How to Implement a BAdI 

In the previous example (Building Your First BAdI) you defined a BAdI, provided a fallback class, instantiated the BAdI and
called a BAdI method. You also provided an enhancement spot to serve as a container for the BAdI.

As you already know, the fallback class is chosen in case no BAdI implementation is available. As you have not created a BAdI
implementation so far, the method implementation of the fallback class is used in your example code.

In this section you will learn how to create a BAdI implementation. As soon as there is a suitable BAdI implementation, the
methods of the fallback class are not used any longer.

The entries you have so far are:

●      Enhancement spot z_es_calc_tax, in which the BAdI z_badi_calc_vat lives.

●      Interface z_if_calc_vat with one method get_vat().

The BAdI interface defines an important part of the BAdI identity. It defines the BAdI methods that can be used.

Create a Container for the Implementation

The definition and the implementation of BAdIs have one similarity – just as you need an enhancement spot to act as a container
for the BAdI, you cannot build a BAdI implementation unless you have the relevant container first.
The relevant container type for BAdI implementations is called a (simple) enhancement implementation. A simple enhancement
implementation can keep many different BAdI implementations, but with one restriction: a simple enhancement implementation is
uniquely assigned to an enhancement spot. That is, a (simple) enhancement implementation can keep only BAdI implementations
of BAdIs that belong to the spot the simple enhancement implementation is assigned to. Therefore, a (simple) enhancement
implementation cannot keep BAdI implementations that implement BAdIs belonging to different spots.

That is why you have to create a container that is uniquely assigned to the enhancement spot to which your BAdI belongs. The
respective tool in the SE80 has paved a smooth way to do this:

1.      In the Object Navigator (transaction SE80), open the enhancement spot you have already created and choose the Create
Enhancement Implementation pushbutton.

       2.      In the new dialog that appears, create a (simple) enhancement implementation:

       3.      

The following new window opens:

What are you asked to enter here?

You have created so far a container for BAdI implementations- an enhancement implementation. This container is uniquely
assigned to your enhancement spot. Once this connection is established, you can create a BAdI implementation for the
BAdI within the enhancement spot. Since you have defined only one BAdI within the enhancement spot, you have no
choice. If you had more BAdIs in your enhancement spot, this will be the point where you would select which BAdI you
want to implement.
       4.      Enter z_bdi_calc_vat_us as the name of the BAdI implementation, confirm and save the enhancement spot in the next
figure, which shows a (simple) enhancement implementation that contains the BAdI implementation z_bdi_calc_vat_us:

The appearance of a (simple) enhancement implementation in the tool is pretty much like the one of an enhancement spot.
Under the Enh. Implementation Elements tab there is a tree with the BAdI implementation(s) contained on the right-hand
side. On the left, you see the properties of the marked BAdI implementation.

Select the property Implementation is active in the Runtime Behavior pane in the figure above. If you do this, the
text below changes to Implementation is called. This is intended to help you understand what the selection you
have just made is for. Further below, there is a list that shows the properties of the BAdI definition your BAdI
implementation is assigned to.

The Implementing Class

Now that you have a BAdI implementation, you need an implementing class.

       1.      Choose the triangle in front of the name of the BAdI implementation in the tree.
       2.      In the Implementing Class field, enter z_cl_calc_vat_us and choose the Change pushbutton.

The Class Builder opens. The relevant interface methods are already defined there. In your case it is only the
method get_vat().

       3.      Implement the method using the following source snippet:

DATA: percent type p value 4 .

ex_amount_vat = im_amount * percent / 100 .

ex_percent_vat = percent .

       4.      Save and activate the class.

       5.      Return to the program and enter the following code:
 DATA: handle TYPE REF TO z_badi_calc_vat,

sum TYPE p,

vat TYPE p,

percent TYPE p.

sum = 50.

GET BADI handle.

CALL BADI handle->get_vat

EXPORTING im_amount = sum

IMPORTING ex_amount_vat = vat

         ex_percent_vat = percent.

WRITE: 'percentage:', percent, 'VAT:', vat.

       6.      Run the program.

The result is a percentage of four percent. This is because the fallback class is not selected when there is an active BAdI
implementation.

Creating a Second BAdI Implementation

       1.      Create another BAdI implementation, this time with the VAT rate of Great Britain.

To make your example more like real world programming, you create another enhancement implementation, that is, another
container. This is because implementing the taxes for different countries most probably belongs to different projects and
because the structure of the (simple) enhancement implementations must mirror the project structure.

       2.      Navigate to your enhancement spot and use the same button as you have done above. Name the simple enhancement
implementation z_ei_bad_calc_gb, the BAdI implementation z_bdi_calc_vat_gb, and the implementing
class Z_BDI_CALC_VAT_GB. The implementation of the method get_vat is the same as for USA except for the VAT rate,
which you assume to be 16.5%.
       3.      After saving and activating the enhancement implementation and the class, return to the program and run it again.

This time you get a short dump with the exception cx_badi_multiply_implemented.

You have defined a single-use BAdI by deselecting the Multiple Use option. When instantiating a single-use BAdI,
you have to make sure that there is only one active non-default implementation. Otherwise, you get the respective
exceptions at runtime.

What you need now is a way to select among different BAdI implementations. That can be easily done with filters. For more
information, see How to Use Filters.

How to Use Filters 

Recalling from the previous step (How to Implement a BAdI), you need a way to select between
different BAdI implementations. This is where you need the BAdI filter.
What you need is to change the BAdI definition. You can define one or many filters for a BAdI.
For the purpose of this example, you create only one filter. Therefore, in this step you define the
filter in the BAdI definition, determine filter values for the respective BAdI implementation, and
use the filter in the instantiation of the BAdI handle.

When modifying your example you do not take into account the differentiation
between the BAdI provider and the implementer. In real life it is the BAdI provider
who defines a BAdI with a filter or adds a filter to an existing BAdI. It is also part of
this role to use the filter condition to select the respective BAdI implementation in the
ABAP code. It is the implementer who determines the filter value(s) or an interval for
one or many BAdI implementations. For more information about the different roles,
see BAdIs Concept.
       1.      Navigate to your enhancement spot and open the Enh. Spot Element Definition tab that
shows a list of all the enhancement elements of the spot.
       2.      Switch to a change mode, select your BAdI in the list, and choose the Filter icon from

the toolbar above.

The following dialog appears, where you fill in the corresponding fields:

        3.      Confirm the entries.

The filter is now visible as a property below the BAdI.
4.      Activate the enhancement spot, double-click on the implementation and navigate to the
       

respective BAdI implementation by double-clicking the respective row in the table of BAdI
implementations.
       5.      Switch to change mode, double -click the triangle in front of the BAdI implementation in
the tree and then double-click on the filter icon below.
       6.      On the next screen, select the Combination icon.

       7.      Select Country as the filter and confirm

       8.      Double-click on the row below Combination 1.

A new dialog opens:

 
        9.      Activate the (simple) enhancement implementation and navigate back to the spot.
The other implementation, that is the one for USA, also needs the respective filter value.
So you go to the respective (simple) enhancement implementation and change the BAdI
implementation in the same way as you just did above. The respective filter value for this
country is 'US'.
10.      Return to your program and adapt it to the modified BAdI. Running the syntax check
   

shows you that you need to have a filter parameter in the GET BADI command if the BAdI you
try to instantiate is defined with a filter. The required addition to the GET BADI command
is FILTERS. It is after this keyword that you insert the name of the BAdI filter and a value the
filter is compared to. You also have to take care that an appropriate value can be passed to
the GET BADI routine:
REPORT  Z_DEMO_ENH.
 parameters: ctry(2) type c.
DATA: handle TYPE REF TO z_badi_calc_vat,
sum TYPE p,
vat TYPE p,
percent TYPE p.
sum = 50.
GET BADI handle FILTERS Country = ctry.
CALL BADI handle->get_vat
  EXPORTING im_amount = sum
  IMPORTING ex_amount_vat = vat
         ex_percent_vat = percent.
WRITE: 'percentage:', percent, 'VAT:' ,vat.
If you pass GB to the parameter ctry, you get a VAT rate of 16.5 percent. If the value of
the parameter ctry is US, the VAT rate is 4 percent. When the parameter ctry has any other
value, you still get a calculated value for the data field percent. This is because you have
defined a fallback class for your BAdI. The fallback class is not only selected if no BAdI
implementation is available, but also if none of the existing BAdI implementations meets
the filter conditions in the GET BADI command. Accordingly, you get a VAT rate of 20
percent, which is the VAT rate you have implemented in the method get_vat in the fallback
class.

Migrating Classic BAdIs 

Due to that fact that calling new BAdIs is significantly faster, we recommend that
you define only new BAdIs and migrate all classic BAdIs and their calls to new
BAdIs. Make sure that you migrateonly your own BAdIs. Customers should never
migrate the BAdIs that are provided by SAP.
A completely automated migration of all existing classic BAdIs is impossible because of the
existing differences between classic and new BAdIs. For that reason, we recommend that you
use the procedure for semi-automatic migration.

Differences Between Classic and New BAdIs 

Classic and new BAdIs differ in a number of features important for migration:
●      BAdI object
                            a.      In the case of classic BAdIs, you create a BAdI object by calling a factory
method and reference it by means of a reference variable of the type of the BAdI interface.
                            b.      In the case of new BadIs, you create a BAdI object with the ABAP

statement GET BADIas a handle for the calls of BAdI methods and you reference it with a
reference variable of the type of the BAdI. A BAdI object is an instance of an internal BAdI
class which is invisible to the outside world.
 ●      Passing comparison values for the filter
                            a.      In the case of classic BAdIs, the filter values are stored in a structure and passed
with the call of the BAdI methods.
                            b.      In the case of new BAdIs, the comparison values for the filters used to search

for implementations are passed when the BAdI object is created with the GET
BADIstatement.

Migrating BAdIs 
       1.      Call the classical BAdI Builder (transaction SE18).
       2.      Enter the name of the BAdI you want to migrate.

       3.      Choose Utilities → Migrate.

                            a.      Specify an enhancement spot. For more information, see Creating, Editing, and

Deleting Enhancement Spots.
                            b.      Specify an enhancement implementation. For more information, see Creating,

Editing, and Deleting Enhancement Implementations.

        4.      Transport the change into a follow-up system:
a.      Call transaction SPAU if a BAdI implementation exists for a migrated BAdI.
                            

In this case, a message with identifier 6 will appear in the input log of the
transport request.
                            b.      Choose the traffic light in front of the BAdI implementation.
                            c.      Enter an enhancement implementation.

Tips and Tricks 

Organization of BAdIs
Large BAdI interfaces were often needed for classic BAdIs to combine related functions. In the
case of new BAdIs, you can divide related functions between several small BAdIs, which are
then administered together in a common enhancement spot. In that way you can avoid the
disadvantages of large BAdIs like terminating the program if any additionally included methods
are not implemented or blurring the structure of the enhancement.
Contexts for BAdIs
The instance generation mode of a BAdI can be context-dependent. If you have context-
dependent BAdIs, you must specify an object reference variable to a BAdI context object (an
object whose class implements the tag interface IF_BADI_CONTEXT) in the GET
BADI statement. As a result, within an internal session for the same BAdI context object, the
same object plug-ins are always used. Such object plug-ins are singletons as far as their BAdI
implementation class and a BAdI context object are concerned. Using a context-dependent BAdI
is linked to a program is illustrated in the example below.
Example
By using the predefined global class cl_badi_report_contextyou can easily couple BAdI
implementations to an (executable) program (or more generally, to a compilation unit). This
class implements the interface if_badi_context, has a public attribute repid, and a public static
method get_instance, which creates an object and sets the attribute.
By calling the method cl_badi_report_context=>get_instance, you can create unique instances as
far as the attribute, which can serve as BAdI context object is concerned.
Suppose the BAdI badi_ctx_badi is context-dependent and has no filters. The code fragment
below shows how to use the cl_badi_report_context:
DATA: bd  TYPE REF TO badi_ctx_badi,
      ctx TYPE REF TO cl_badi_report_context.
 
ctx = cl_badi_report=>get_instance( repid = sy-repid ).
GET BADI bd CONTEXT ctx.
The reference variable ctx references an instance that is unique for the current program name. In
this context a BAdI object is requested. If the same code fragment is executed in other programs
in the same internal session, different instances of the BAdI implementation classes are always
associated with the BAdI object.
The class cl_badi_report_context allows you to bind object plug-ins to compilation units. The
methods of these object plug-ins can be called anywhere in the internal session by using the
combinations of GET BADI and CALL BADI shown above. The state is kept in this
connection, which means that the same instances are always called for the same compilation
units.
 

Working with Enhancements 

This section describes how to manage your enhancements:
●      Enhancement Information System (also known as Enhancement Browser)
This tool helps you to obtain a list of all enhancements available in your ABAP-based SAP
system. You can search for enhancements, enhancement upgrades, (composite)
enhancement implementations, and (composite) enhancement spots.
●      Adjusting Enhanced Objects 
Whenever an enhanced repository object has been changed in a previous system and its
enhancement implementation has been affected or may be affected by a semantic change,
use one of the available tools to adjust your enhancements.
 

Enhancement Builder 
The Enhancement Builder is a tool for creating and managing enhancements which is fully
integrated into the ABAP Workbench. You cannot use a transaction code to call it directly.
Besides defining enhancement options for repository objects which can be enhanced within the
enhancement concept and the related actual enhancements, you can edit enhancement
spots and enhancement implementations in the Enhancement Builder.
For more information, see Creating, Editing, and Deleting Enhancement Spots and Creating,
Editing, and Deleting Enhancement Implementations.