Some additions to schema

1. Support UNDEFINED datasets in template mode
2. gridUnitSI may now be a vector

Author: franzpoeschel

share/openPMD/json_schema/dataset_defs.toml

@@ -68,6 +68,19 @@ allOf = [
     { "$ref" = "#/$defs/any_type_dataset_properties", title = "Property definitions" },
 ]
 
+#####################################################
+# ...or `datatype` is UNDEFINED, no extent required #
+#####################################################
+
+[["$defs".any_type_dataset.anyOf]]
+title = "An undefined template dataset"
+allOf = [
+    { required = [
+        "datatype",
+    ], title = "Required properties" },
+    { datatype.value = "UNDEFINED", extent = { type = "array", items.type = "integer" } },
+]
+
 ######################################
 # n-dimensional datasets of int type #
 ######################################

share/openPMD/json_schema/mesh.toml

@@ -32,7 +32,9 @@ required = [
 
 [allOf.properties.attributes.allOf.properties]
 
-gridUnitSI."$ref" = "attribute_defs.json#/$defs/float_attribute"
+# in openPMD 1.0: float_attribute, openPMD 2.0: vec_float_attribute
+# TODO: decide how to better deal with the 1.0/2.0 dichotomy
+gridUnitSI."$ref" = "attribute_defs.json#/$defs/vec_float_attribute"
 gridSpacing."$ref" = "attribute_defs.json#/$defs/vec_float_attribute"
 gridGlobalOffset."$ref" = "attribute_defs.json#/$defs/vec_float_attribute"
 timeOffset."$ref" = "attribute_defs.json#/$defs/float_attribute"