Data Container

The data container is a container holding data for the application. The data consists of objects (rows in the data container) and each object has a series of attributes (columns in the data container).

The data container provides data that can be represented in one or more graphics.

The data to be displayed and its layout generally differ from one application to another. Therefore it is often appropriate to implement an application-specific data container. For this purpose a program called a data container wizard can be used to implement a data container for a given DDIC structure (for more information, see Data Container Wizard). However, there is a standard implementation of the data container for each graphics type that you can use to save time.

You can set values for objects in the data container using Set methods. These methods do not send return values. You can access values from the data container using Get methods. In this case the return value indicates any ambiguity involved. If an object is not identified uniquely by the field identifier (name of the attribute of a specific data object) the data container returns an error - depending on the method concerned. For more information, see Reading and Changing Values.

The data contained in the data container at any one time is known as the dataset. For every dataset there is a flag Reversible (Y/N) and an indication as to whether there are changes (locked/released and if applicable the number of changes). You can reverse changes made by reverting to previous datasets. For more information, see Undo and Named Datasets.

The local data in the data container contains a list of the graphics proxies subscribed to the data container and a status for the current dataset. The status could indicate, for example, that an event/change from a graphics proxy has been made in the data container (and which proxies) and that the changes have not yet been released/validated.

A possible structure of a data container is described in detail in Data Containers for Business Graphics.

The application generates the data container that serves as the central pool of data for all the graphics proxies subscribed to it. It is defined by its interface IF_DC_MANAGEMENT so any development team can implement it.

The data container has the following global interfaces:

• IF_DC_MANAGEMENT - the interface for the application

• IF_DC_SUBSCRIPTION - the interface for the graphics proxy

• IF_DC_ACCESS - the interface for accessing data

This final interface is contained in both of the other interfaces - it is a nested interface.

The graphic shows the data container, its data storage and local data and its interfaces to other objects within the Graphical Framework. It has interfaces both to the application and to its graphics proxies.