Reading and Changing Values

Use

You can read data from the data container, read changes to values of data and maintain data in the following ways:

Reading/Changing data

Fields/Rows/Tables

Comments

Reading data

Field by field

Using method GET_VALUE

Reading data

Row by row

For specific data containers

Reading changes to values

Field by field

Using method GET_CHANGES

Maintaining data

Field by field

Using method SET_VALUE

Maintaining data

Row by row

Only for some data containers (1)

Maintaining data

Complete tables

Tables must have a fixed layout

(1) The method is not available in the interface; it is in the implementing class.

Features

To set a value the data container checks the data type and if possible converts it according to the usual ABAP conversion rules.

The data container manages several datasets which means that the Undo function can be used (see also Undo and Named Datasets). The current dataset is distributed to the graphics proxies that are subscribed to the data container on request - for example after a change has been made.

Activities

To be able to inform all subscribed graphics proxies if data is changed it is necessary to recognize such changes. Any changes the application makes to data are marked automatically as released changed by the data container or the dataset is marked as initial if no graphics proxy is subscribed to the data container. Data changed by a graphics proxy is set to changed.

If data is changed and the dataset has not been distributed the data container overwrites its current data and sets the change status of the fields accordingly. If the dataset has already been distributed the changes to the data are entered initially in a copy of the current state. A copy is created automatically after the first change message for a dataset that has been distributed. All further changes are written in the copy and marked as locked (that is, released changed or changed) until they are released (by the application that has been informed of changes by the graphics proxy).

Deleting an object from the data container (method DEL_OBJECT) is a special case of changing a value. This means that a difference-update of the graphics proxies is also possible where objects are deleted.

A sequence of changes must be completed with a distribution order to the data container (see method DISTRIBUTE_CHANGES in Communication Data Container <-> Graphics Proxy). This is so the data container tells the graphics proxies that are subscribed to it about the changes and sets the change flag to initial or deletes the objects.