allowing null values for some fields

metadata_tools/resources/elu-core.json

@@ -57,6 +57,7 @@
             "format": "email"
           },
           "affiliations": {
+            "description": "Names of the affiliated institutions.",
             "type": "array",
             "items": {
               "type": "string"

metadata_tools/resources/elu-dataset.json

@@ -10,7 +10,8 @@
   ],
   "properties": {
     "project": {
-      "type": "string"
+      "description": "Name of the project the dataset belongs to.",
+      "type": ["string", "null"]
     },
     "data_declarations": {
       "type": "array",
@@ -49,9 +50,9 @@
       "type": "object",
       "properties": {
         "partner": {"type": "string"},
-        "transfer_details": {"type": "string"},
+        "transfer_details": {"type": ["string", "null"]},
         "transfer_date": {
-          "type": "string",
+          "type": ["string", "null"],
           "pattern": "^[0-9]{4}-[0-9]{2}-[0-9]{2}$"
         }
       }

metadata_tools/resources/elu-institution.json

@@ -36,11 +36,11 @@
           ]
         },
         "address": {
-          "type": "string"
+          "type": ["string", "null"]
         },
         "country_code":{
           "title": "ISO 3166-1 Alpha-2 Country code",
-          "type": "string",
+          "type": ["string", "null"],
           "pattern": "^[A-Z]{2}$"
         }
       }

metadata_tools/resources/elu-project.json

@@ -19,20 +19,20 @@
           "type": "boolean"
         },
         "institutional_ethics_approval_notes": {
-          "type": "string"
+          "type": ["string", "null"]
         },
         "has_national_ethics_approval": {
           "type": "boolean"
         },
         "national_ethics_approval_notes": {
-          "type": "string"
+          "type": ["string", "null"]
         },
         "start_date": {
-          "type": "string",
+          "type": ["string", "null"],
           "pattern": "^[0-9]{4}-[0-9]{2}-[0-9]{2}$"
         },
         "end_date": {
-          "type": "string",
+          "type": ["string", "null"],
           "pattern": "^[0-9]{4}-[0-9]{2}-[0-9]{2}$"
         }
       }