Designing Custom Encoders

Abstract Message Structure

The runtime message structure is composed of a hierarchical system of nodes. These nodes are characterized by terms indicating their relationships with each other:

Parent, Child, and Sibling Nodes

Any subnode of a given node is called a child node, and the given node, in turn, is the child’s parent. Sibling nodes are nodes on the same hierarchical level under the same parent node. Nodes higher than a given node in the same lineage are ancestors and those below it are descendants.

Figure 1 Encoder Node Relationships

Figure described in content.

Root Nodes

The root node is the highest node in the tree structure, and has no parent. This node is a global element and represents the entire message. It may have one or more child nodes, but can never have sibling nodes or be repeating. The name of the root node can be edited.

Non-leaf Nodes

Non-leaf nodes, which can have children, provide the framework through which this data is accessed and organized. They are of complex types.

There are two major types of non-leaf nodes (aside from a root node, which is a special case):

Leaf Nodes

Leaf nodes have no children, and normally carry the actual data from the message. They are of simple types such as string.

The basic node types are fixedLength and delimited. See Encoding Properties for information about other node types.