add relations to metadata element

Author: pvgenuchten

docs/content/reference/mcf.md

@@ -130,6 +130,7 @@ language|Mandatory|primary language used for documenting metadata, the metadata
 language_alternate|Optional|alternate language used for documenting metadata|en|ISO 19115:2003 Annex J
 charset|Mandatory|full name of the character coding standard used for the metadata set|utf8|ISO 19115:2003 Section B.2.1
 parentidentifier|Optional|file identifier of the metadata to which this metadata is a subset|11800c2c-e6b9-11df-b9ae-0014c2c33ebe|ISO 19115:2003 Section B.2.1
+relations|Optional|relations between this record and other records, identified by identifier and type|11800c2c-e6b9-11df-b9ae-0014c2c33ebe|ISO 19115:2003 Section B.2.2.7
 hierarchylevel|Mandatory|level to which the metadata applies (must be one of 'series', 'software', 'featureType', 'model', 'collectionHardware', 'collectionSession', 'nonGeographicDataset', 'propertyType', 'fieldSession', 'dataset', 'service', 'attribute', 'attributeType', 'tile', 'feature', 'dimensionGroup'|dataset|ISO 19115:2003 Section B.2.1
 datestamp|Mandatory|date that the metadata was created, pygeometa supports specifying the $date$ or $datetime$ variable to update the date value at run time|2000-11-11 or 2000-01-12T11:11:11Z|ISO 19115:2003 Section B.2.1
 dataseturi|Optional|Uniformed Resource Identifier (URI) of the dataset to which the metadata applies|`urn:x-wmo:md:int.wmo.wis::http://geo.woudc.org/def/data/uv-radiation/uv-irradiance`|ISO 19115:2003 Section B.2.1

pygeometa/schemas/mcf/core.yaml

@@ -39,6 +39,17 @@ properties:
             parentidentifier:
                 type: string
                 description: file identifier of the metadata to which this metadata is a subset
+            relations:
+                type: array
+                description: relations to other records
+                items:
+                    type: object
+                    allOf:
+                        - $ref: '#/definitions/identifier_scheme'
+                    properties:
+                        type:
+                            type: string
+                            description: a relation type (source, partof, version, reference, ...)
             hierarchylevel:
                 type: string
                 description: level to which the metadata applies

sample.yml

@@ -10,6 +10,10 @@ metadata:
     language_alternate: fr
     charset: utf8
     parentidentifier: someparentid
+    relations:
+        - identifier: 10.278/45e22-11223-2
+          scheme: http://doi.org
+          type: source 
     hierarchylevel: dataset
     datestamp: 2014-11-11
     dataseturi: http://some/minted/uri