WebSphere Business Integration Adapters: An Adapter Development and WebSphere Business Integration Solution

70 WebSphere Business Integration Adapters

Outcome status for Delete verb processing

The Delete operation should return one of the outcome status values as shown

in Table 6-7.

Table 6-7 Possible outcome status for Delete verb processing

6.7 Business object processing and cardinality

A business object handler’s role is to deconstruct a request business object,

process the request, and perform the requested operation in the application. To

do this, a business object handler extracts verb and attribute information from the

request business object and generates an API call, SQL statement, or other type

of application interaction to perform the operation.

Basic business object processing involves extracting metadata from the

business object’s application-specific information (if it exists) and accessing the

attribute values. The actions to take on the attribute value depend on whether the

business object is

flat or hierarchical. This section provides an overview of how

a business object handler can process these types of business objects.

6.7.1 Processing flat business objects

If a business object does not contain any other business objects (called child

business objects), it is called a

flat business object. All the attributes in a flat

business object are simple attributes (that is, each attribute contains an actual

value, not a reference to another business object).

After the verb operation has accessed the information that it needs within the

business object definition, it often needs to access information about attributes.

Attribute properties include the cardinality, key or foreign key designation, and

maximum length. For example, the Create method might need to obtain the

attribute’s application-specific information. A connector business object handler

Delete condition Outcome status

InterChange Server only: In most cases, the

connector returns a “Value Changed” outcome status

to enable the system to clean up the relationship

tables after a delete operation.

VALCHANGE

All integration brokers: If the Delete operation is

unsuccessful, it:

 Fills a return-status descriptor with additional

information about the cause of the delete error.

 Returns a “Fail” outcome status.

FAIL

Chapter 6. Business object handlers 71

typically uses the attribute properties to decide how to process the attribute

value.

For a

database-oriented application, the business object handler that handles a

flat business object, deconstructing a business object includes the following

steps:

1. Extracts the table and column names from the application-specific information

in the business object definition.

2. Extracts the values of the attributes from the business object instance.

As Figure 6-4 shows, the Customer business object definition is designed for a

metadata-driven connector. Its business object definition includes

application-specific information that the verb operation uses to locate the

application entity upon which operates.

Figure 6-4 Business object definition and business object instance

Important: Application-specific information is also used to store information

about foreign keys and other types of relationships between entities in the

application database. A metadata-driven connector can use this information to

build an SQL statement or an API call.

Business Object Definition

Customer

Business Object Instance

CustomerId

IsKey = True

Type = Integer

AppSpecificInfo = cust_key

CustomerName

Type = String

AppSpecificInfo = cust_name

CustomerStatus

Type = String

AppSpecificInfo = cust_status

CustomerRegion

Type = String

AppSpecificInfo = cust_region

ObjectEventId

Customer

Verb = Create

CustomerId = 1150

CustomerName = Jones

CustomerStatus = Active

CustomerRegion = North

ObjectEventId

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6.7.2 Processing hierarchical business objects

Business objects are hierarchical when parent business objects can contain child

business objects, which can, in turn, contain child business objects, and so on. A

hierarchical business object is composed of a

top-level business object, which is

the business object at the very top of the hierarchy, and

child business objects,

which are all business objects under the top-level business object. A child

business object is contained in a parent object as an attribute.

There are two types of containment relationships between parent and child

business objects:

 Cardinality 1 containment: The attribute contains a single child business

object.

 Cardinality n containment: The attribute contains several child business

objects in a structure called a business object array.

Figure 6-5 shows a typical hierarchical business object. The top-level business

object has both cardinality 1 and cardinality n relationships with child business

objects.

Figure 6-5 Hierarchical business object

Cardinality 1

Containment

Cardinality n

Containment

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