The links object is an array of trace links to other Eiffel events. These trace links by definition always reference backwards in time – it is only possible to reference an event that has already occurred. Each trace link is an object consisting of
- a type,
- a UUID corresponding to the meta.id of the target event, on string format, and
- optionally the id of the domain where the target event was published (i.e. its meta.source.domainId member). The absence of a domain id means that the target event was sent in, or can at least be retrieved from, the same domain as the current event.
Some link types allow multiple trace links, whereas others only allow one.
Example syntax of a simple links object:
"links": [
{
"type": "CAUSE",
"target": "8f3e0f94-5d11-46e7-ae02-91efa15d2329"
},
{
"type": "COMPOSITION",
"target": "43ee71d2-6d91-496a-b9cf-d121ff1d1bcf"
}
]
Example syntax of a links object that references an event in another domain:
"links": [
{
"type": "CAUSE",
"target": "a3bf3f06-a0e0-4595-a117-3393c178eb81",
"domainId": "com.example"
}
]
The full list of optional and required links is described in the documentation of each respective event type.