Business Collection (SAP Library - Mobile Application Studio)

Business Collection

Definition

A business collection acts as a container for a set of business object records.

Use

A collection is used when business objects are linked in a one-to-many relation. The first object gets an attribute, which is a collection of objects of the second class.

It is also the result of a business query to retrieve business object records according to specific criteria.

Structure

Objects can be added, retrieved, deleted or enumerated from the collection. However, business objects in general are not instantiated. It is only possible to instantiate them out of the data contained within the business collection.

It has a BDoc (Business Document) record-set, which contains data that is read by the Business Collection. Each item in the Business Collection corresponds to a row of data in the record-set. The record-set is built via a Read BDoc, which is stored in the BDoc Repository and specifies the potential range of business objects that can be loaded. The Read BDoc of the collection retrieves attribute values of the business objects (without creating the objects) and displays them in a user interface grid object via Data Binding. The BDoc can also fetch data that does not directly belong to a business object.

Depending on the parameters passed in the BDoc, data is loaded from the User Database into the record-set. If the Business Object is created, the Business Collection will directly expose data from Business Object instead of the data held by the Business Collection.

Note

For optimization reasons the Business Objects are not created when the collection is created; they are created only on demand. The Business Collection has methods that allow you to manipulate the Business Objects it holds. You can:

navigate through the collection.
add, retrieve or remove business objects from the collection.
set/retrieve values and properties of the business objects in the collection.

Integration

Getting a filled Business Collection

You can get a filled Business Collection by:

Directly using the Business Factory. Such a master collection contains all Business Objects of the defined type that are stored in the User Database. In most cases, this results in a query which requires a lot of resources because a very large number of Business Objects are involved. So it is practical only in selected cases.
Using the Business Query, which allows retrieving a number of selected business objects, which fulfill certain criteria.
a one-to-many (1:n) relationship between Business Objects. In such relationships, one Business Object has a Business Collection of related objects as an attribute.