Changes between Version 4 and Version 5 of DataFormat

Timestamp:

02.09.2011 18:05:24 (13 years ago)

Author:

jri

Comment:

Topic format explanation

DataFormat

@@ -3 +3 @@
 = Data Format =
 
+This page describes the data format of DeepaMehta's core objects (and some application objects) as retrieved via the [[RestApi|REST API]].
+
+Note: The format used in create and update operations differs slightly. See the respective notes on the REST API page.
+
 == Topic ==
+
+A topic object has always 5 properties:
+
+||= Property =||= Description =||= Format =||
+|| `id` || A system-generated ID. || A number (long), e.g. `2735` ||
+|| `uri` || A globally unique identifier.\\Typically assigned by human.\\If no URI is assigned: an empty string. || A string of format <domain>.<project>.<name> ||
+|| `type_uri` || The URI of the topic's type. || A string of format <domain>.<project>.<name>, e.g. `ffnet.geomap.access_point` ||
+|| `value` || For a simple topic^1)^: the topic's payload.\\Note: For a complex topic the value is derived from the `composite` property. || A simple value: string, int, long, or boolean. ||
+|| `composite` || For a complex topic^2)^: a nested object representation.\\(For a simple topic: an empty object.) || See examples 2 and 3 below. ||
+
+^1)^ The term ''simple topic'' refers to an instance of a simple topic type. A simple topic type is one of data type "Text", "Number", "Boolean", or "HTML". See DataFormat#TopicType.
+
+^2)^ The term ''complex topic'' refers to an instance of a complex topic type. A complex topic type is one of data type "Composite". It is composed of child topic types (arbitrary depth).
 
 Example 1: a simple topic