Deep Inside the Essbase Java API - Developing Essbase Applications - page 280

Figure 8.2 Essbase data classes. (From Oracle Essbase Administration Services. With permission.)
sense that an Essbase operation applies to an Essbase database. The standard Essbase
operations also are represented as objects in the Java API. For example, the IEssCubeView
interface contains a createIEssOpRetrieve method that returns, naturally, an instance of
the IEssOpRetrieve object. he IEssOpRetrieve instance is then passed as an argument to
the IEssCubeView.performOperation.
When you first consider the idea that Essbase operations are represented as objects,
it may seem counterintuitive. once you start looking at the interface definitions for
the Essbase operations, the reason that Essbase operations are considered objects starts
to make sense. many Essbase operations require a number of optional parameters for
execution, and wrapping these parameters into an object is an elegant solution for pass-
ing those parameters. For example, the Essbase zoom In operation requires one or more
member cells to be selected for the zoom operation to work properly. If you think about
how the zoom In operation works in the classic Essbase Excel add-in, it makes sense
that you cannot zoom In if you have not selected a member.
In addition to containing the operation objects, the IEssCubeView object is also the con-
tainer object for Essbase query options. The IEssCubeView includes methods for controlling
options including the zoom level, the alias table, whether member names or alias names
are displayed, and whether zoom operations suppress missing rows. The method names
for these options are intuitive, and for the options mentioned above, the corresponding
methods are named setDrillLevel , setAliasTable , setAliasNames, and setSuppressMissing .
When most Essbase users think about Essbase operations, such as retrieve and
zoom In, they think of those operations as occurring in the context of an Excel spread-
sheet. In the Java API, there is not an Excel spreadsheet to provide the member grid
for the operation. Instead of a spreadsheet, the Java API uses the IEssGridView inter-
face to provide the member grid. An instance of an IEssGridView is obtained from the
IEssCubeView instance using the IEssCubeView.getGridView method. An IEssGridView
instance is a multidimensional array of information used both to form the member lay-
out for an operation and to return values after the operation is performed. It is easy to
visualize the data that is returned from a retrieve operation in the classic Excel add-in.
he IEssGridView object is, in many ways, a virtual representation of this data, but it