Data structures and meaning
Document and embedded-object schema
A document model: nested objects, arrays and embedded structures with their containment rules.
ddn@1New DDN source
Why use it?
Tree-shaped data needs its own contract — tables of one row type do not describe nesting.
When it helps
Designing JSON documents, message payloads, or any hierarchical record.
How to read it
- Containment reads top-down: each level owns the fields below it.
- Arrays are plural by contract, not by current length.
What you need
- The nesting levels
- Which fields are arrays
- Required-versus-optional per node
Things to check
- Do not flatten a tree into parallel tables just because it feels relational.
- An optional node with required children is usually a modeling mistake.
Scope of this diagram
Structural contract only; no validation engine runs against live documents.
Work with the converted example
- Open the viewer and select
diagram. Inspect the rendered view and its source. - Open the designer. Keep the selected profile and inspect its legal palette and property controls.
- Change one displayed title or an appropriate data value. Apply the edit and check the resulting diagram.
- Run the verifier and review its diagnostics before moving complete content into review.
- Download your edited DDN source to retain the change.
The example uses the indentation-based ddn-next-1 dialect. The language guide explains reusable definitions, dotted data rows and explicit property blocks.