Groups (XSM)

A group of elements is a set of elements arranged by a group particle (all, choice or sequence), which is then referenced in the model by various elements.

A group - is created independently, without a parent element, and can be reused multiple times by elements, complex types or other global groups, through references. In a schema, it is directly linked to the <schema> tag (root element). See Creating a group.
A reference to a group - is created within an element, complex type or global group, and makes the referenced group available to its parent. See Creating a reference to a group.

For example:

The descriptionLines group is reused in the definition of the product element by clicking the sequence group particle (S) with the Toolbox Group tool. The Reference property of the referencing group property sheet is then set to descriptionLines.

In the generated XSD file, the group is first declared with the <group> tag and then reused through a reference (ref) set to descriptionLines:

In the generated DTD file, the group is expanded directly within its parent element:
In the generated XDR file, the group is declared through a <group> tag, within an <ElementType> tag with its order attribute set to seq:

Note: In a model targeted with DTD or XDR language, there are no global or referencing groups, although they appear on the diagram. Groups are expanded within their parent element and their child elements are declared individually as global elements. (See generated DTD and XDR files in Groups (XSM))

Creating a Group
You can create a group from the Toolbox, Browser, or Model menu. Groups are created at the model root to be referenced by other elements.
Creating a Reference to a Group
A reference to a group is created as a child of an element, group or complex type, and makes the referenced group available to its parent.
Group Properties
To view or edit a group's properties, double-click its diagram symbol or Browser or list entry. The property sheet tabs and fields listed here are those available by default, before any customization of the interface by you or an administrator.

Parent topic: XML Diagrams