From 66fc7b6055093884e70d7eec00d11b9aa99296c9 Mon Sep 17 00:00:00 2001
From: Jan Speckamp <j.speckamp@52North.org>
Date: Mon, 16 Dec 2024 11:30:30 +0100
Subject: [PATCH] Allow null for auto-generated DataStream properties (fixes
 #65) (#93)

---
 .../openapi/schemas/json/dataStream.json      | 107 +++++++++++++-----
 ...ause_8_requirements_class_datastreams.adoc |   3 +
 2 files changed, 82 insertions(+), 28 deletions(-)

diff --git a/api/part2/openapi/schemas/json/dataStream.json b/api/part2/openapi/schemas/json/dataStream.json
index d7cf5ed1..e716273f 100644
--- a/api/part2/openapi/schemas/json/dataStream.json
+++ b/api/part2/openapi/schemas/json/dataStream.json
@@ -1,7 +1,9 @@
 {
   "$schema": "http://json-schema.org/draft-07/schema",
   "allOf": [
-    { "$ref": "baseStream.json" },
+    {
+      "$ref": "baseStream.json"
+    },
     {
       "properties": {
         "system@link": {
@@ -30,29 +32,43 @@
           "$ref": "../common/commonDefs.json#/definitions/Link"
         },
         "observedProperties": {
-          "description": "List of observed properties included in this datastream",
-          "type": "array",
-          "minItems": 1,
-          "items": {
-            "type": "object",
-            "properties": {
-              "definition": {
-                "type": "string",
-                "format": "uri"
-              },
-              "label": {
-                "type": "string"
-              },
-              "description": {
-                "type": "string"
+          "oneOf": [
+            {
+              "type": "null"
+            },
+            {
+              "description": "List of observed properties included in this datastream",
+              "type": "array",
+              "minItems": 1,
+              "items": {
+                "type": "object",
+                "properties": {
+                  "definition": {
+                    "type": "string",
+                    "format": "uri"
+                  },
+                  "label": {
+                    "type": "string"
+                  },
+                  "description": {
+                    "type": "string"
+                  }
+                }
               }
             }
-          },
+          ],
           "readOnly": true
         },
         "phenomenonTime": {
-          "description": "Time extent spanning all phenomenon times of observations in this datastream",
-          "$ref": "../common/commonDefs.json#/definitions/TimePeriod",
+          "oneOf": [
+            {
+              "type": "null"
+            },
+            {
+              "description": "Time extent spanning all phenomenon times of observations in this datastream",
+              "$ref": "../common/commonDefs.json#/definitions/TimePeriod"
+            }
+          ],
           "readOnly": true
         },
         "phenomenonTimeInterval": {
@@ -61,8 +77,15 @@
           "format": "duration"
         },
         "resultTime": {
-          "description": "Time extent spanning all result times of observations in this datastream",
-          "$ref": "../common/commonDefs.json#/definitions/TimePeriod",
+          "oneOf": [
+            {
+              "type": "null"
+            },
+            {
+              "description": "Time extent spanning all result times of observations in this datastream",
+              "$ref": "../common/commonDefs.json#/definitions/TimePeriod"
+            }
+          ],
           "readOnly": true
         },
         "resultTimeInterval": {
@@ -72,17 +95,39 @@
         },
         "type": {
           "type": "string",
-          "enum": ["status", "observation"]
+          "enum": [
+            "status",
+            "observation"
+          ]
         },
         "resultType": {
-          "type": "string",
-          "enum": ["measure", "vector", "record", "coverage", "complex"],
+          "oneOf": [
+            {
+              "type": "null"
+            },
+            {
+              "type": "string",
+              "enum": [
+                "measure",
+                "vector",
+                "record",
+                "coverage",
+                "complex"
+              ]
+            }
+          ],
           "readOnly": true
         },
         "live": {
-          "description": "Flag indicating if the datastream is currently streaming data",
-          "type": "boolean",
-          "readOnly": true
+          "oneOf": [
+            {
+              "type": "null"
+            },
+            {
+              "description": "Flag indicating if the datastream is currently streaming data",
+              "type": "boolean"
+            }
+          ]
         },
         "schema": {
           "description": "Schema describing the content of observations in this datastream. The exact syntax of the schema depends on the encoding format.",
@@ -97,6 +142,12 @@
     }
   ],
   "required": [
-    "name", "system@link", "observedProperties", "phenomenonTime", "resultTime", "resultType", "live"
+    "name",
+    "system@link",
+    "observedProperties",
+    "phenomenonTime",
+    "resultTime",
+    "resultType",
+    "live"
   ]
 }
\ No newline at end of file
diff --git a/api/part2/standard/sections/clause_8_requirements_class_datastreams.adoc b/api/part2/standard/sections/clause_8_requirements_class_datastreams.adoc
index d13140e8..1b3c0718 100644
--- a/api/part2/standard/sections/clause_8_requirements_class_datastreams.adoc
+++ b/api/part2/standard/sections/clause_8_requirements_class_datastreams.adoc
@@ -54,6 +54,9 @@ The following tables describe the attributes and associations of a `DataStream`
 | `formats`            | - | The list of formats that the observations in the datastream can be encoded to. | List<String> | Required
 |====
 
+The values for the properties `observedProperties`, `phenomenonTime`, `resultTime`, `resultType` SHALL be automatically generated by the server based the `Observations` that are linked to the `Datastream`. If there are no linked Observations the properties SHALL be set to `null`.
+The property `live` MAY be generated by the server. In this case the server MAY ignore updates to the property.
+
 [#datastream-types,reftext='{table-caption} {counter:table-num}']
 .DataStream Types
 [width="100%",options="header"]