Independent and Dependent Nodes 

Contexts do not only contain nodes that are independent of each other on one level, but also those that are hierarchically related to each other. A node (called a parent node) can contain other nodes (child nodes). Context nodes directly below the root node are known as independent nodes; all the other nodes are called dependent nodes. Whereas the content of the independent nodes is determined directly by the application, in contrast to this, the content of the child nodes (node elements in the node collection of a child node) depends on which node element they refer to in the parent node. The mechanism that automatically obtains node elements for a dependent node is based on what are called supply functions.

Example

The example context shown contains a top level attribute called Company of type String directly below the root node. An independent node called Customer with cardinality 0..n is also defined. A node element of type Customers is defined by a single context attribute Name as well as an inner, dependent node called Orders. The dependent node itself contains the two context attributes Product and Amount. The property singleton was set to true for the dependent node. As a result, only one single object instance exists for this node at runtime.