Model groups and references, 6 model groups and references – Doremi ShowVault / IMB User Manual

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SHV.OM.001293.DRM

Page 109 of 146

Version 1.5

Doremi Labs

In that case, the type names of simple types are shown as well:

12.6 Model Groups and References

An element group is a named container with one or several elements. The group of elements
can be reused at multiple places in the schema. Model groups are invisible in the instance
document in contrast to types. Model groups have been used sparingly since they do not map to
a feature in object-oriented programming languages, unless they support multiple inheritance.

It is important to note that when reading the diagrams for model groups, the model group
symbol is drawn with simple lines, not dashed. It does not imply that the elements in the model
group are required. The optionality of the group depends on the optionality of elements
contained in the model group. Model groups can be made optional, e.g., to make a model group
with required elements optional in some cases, but this has not been used.

The any group is a special kind of model group. It is a placeholder for elements not defined in
the schema. The any element defines points where the schema can be extended. After the any
keyword, the namespace from which the elements may come is defined. For example, "##other"
specifies that the extension elements may come from any namespace, except from the current
schema namespace.

Element references are indicated through a link arrow in the lower left corner. They are similar
to references to model groups within a schema, but instead of refining the model group, they
directly refer to a single global element. The global element can then be reused in multiple
places.

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