The composition of a Meta Entity, Meta Entity Type, or
Meta Data Aggregate must be specified in the Composition tab.
This tab is common to the Meta Entity, Meta Entity Type, and Meta
Data Aggregate editors. For the Meta Entities, the information that
is entered in this tab defines the structure of the User Entities.
In this tab, you define the composition of the Meta Data Aggregates
that are used in Meta Entities. You also specify the composition of
a Meta Entity Type that is used to extend a standard entity.
About this task
A Meta Entity, Meta Entity Type, or Meta Data Aggregate sometimes
has several description levels. A description can call a child description,
which can in turn call a child description. All Meta Entity descriptions
must contain a root element that can be a data aggregate description
or a data description. The root element is unique. You cannot change
its cardinality. A data aggregate description root can contain data
aggregate descriptions, data descriptions, Data Elements (in the
Pacbase facet), Data (in
the COBOL facet), or Meta Data Aggregates.
Procedure
- Open the Composition tab of the
instance.
- If the Composition pane is empty
in a Meta Entity or Meta Entity Type, it means that no description
has been added. To create a description root, click Add and
select Add data aggregate description. Enter
a name and a label in the Data aggregate description section
opens. For a Meta Data Aggregate, the root is created automatically.
It takes the name of the Meta Data Aggregate and cannot be modified
or deleted.
- Click Add again and select Add
data aggregate description to create the first data aggregate
description. This description can contain data descriptions, Data
Elements (in the Pacbase facet),
Data (in the COBOL facet), and Meta Data Aggregates.
- Then, click Add and select Add
data description to insert data description at this level
of the tree structure. You must enter a type, a definition, the allowed
values, and the intervals in the Data Description section
that automatically opens.
- To insert a Data Element or Data call in the description
tree, click Add and select Add
Data Element (in the Pacbase facet) or Add
Data (in the COBOL facet). In the selection wizard that
opens, click an instance or create an instance. The new instance must
be defined in its dedicated editor. You can also add Meta Data Aggregates
by following the same procedure.
- To create another description level in the tree, click
the data aggregate description root and click Add.
Select Add data aggregate description. Give
the description a name and a label. The number of descriptions in
a Meta Entity or Meta Data Aggregate is not limited.
What to do next
CAUTION:
You are strongly advised against modifying
a Meta Entity when it contains User Entities. It might cause errors.
Do not forget to complete the fields in the definition
panes that open when you insert or select a composition line in the
tree.
When the composition of Meta Entity Type is modified
and saved, the description of the entity that is associated with the
Meta Entity Type is automatically updated. For example, if you modify
the composition of a "Program 3" Meta Entity Type that extends
a Program entity, the "Program 3" tab is updated in the Program
entity.