Added accept header handling for dcat API format parameter.

nomad/app/dcat/api.py

@@ -16,7 +16,7 @@
 # limitations under the License.
 #
 
-from flask import Blueprint, Response
+from flask import Blueprint, Response, request
 from flask_restplus import Api, reqparse
 import urllib.parse
 from rdflib import Graph
@@ -62,13 +62,52 @@ arg_parser.add_argument('format', type=str, choices=[
     'pretty-xml',
     'trig'])
 
+all_repsonse_types = {
+    'application/xml': 'xml',
+    'application/rdf+prettyxml': 'pretty-xml',
+    'application/rdf': 'xml',
+    'application/rdf+xml': 'xml',
+    'text/plain': 'n3',
+    'text/turtle': 'turtle',
+    'text/nt': 'nt',
+    'text/n3': 'n3',
+    'text/rdf+n3': 'n3',
+    'text/rdf+nt': 'nt',
+    'text/rdf+turtle': 'turtle',
+    'application/x-trig': 'trig'
+}
+
+response_types = [
+    'application/xml',
+    'application/rdf+xml',
+    'application/rdf+pretty-xml',
+    'text/plain',
+    'text/turtle',
+    'text/rdf+n3',
+    'text/rdf+nt',
+    'application/x-trig']
+
 
 def rdf_respose(g: Graph) -> Response:
     args = arg_parser.parse_args()
     format_ = args.get('format')
+    accept_header = None
     if format_ is None:
-        format_ = 'pretty-xml'
-    content_type = 'application/xml' if format in ['xml', 'pretty-xml'] else 'text/%s' % format_
+        accept_header = request.headers.get('Accept', None)
+        if accept_header is not None:
+            format_ = all_repsonse_types.get(accept_header, 'pretty-xml')
+        else:
+            accept_header = None
+            format_ = 'pretty-xml'
+
+    if accept_header is not None:
+        content_type = accept_header
+    else:
+        try:
+            content_type = next(key for key, value in all_repsonse_types.items() if value == format_)
+        except StopIteration:
+            content_type = 'application/xml' if format in ['xml', 'pretty-xml'] else 'text/%s' % format_
+
     return Response(
         g.serialize(format=format_).decode('utf-8'), 200,
         {'Content-Type': content_type})

nomad/app/dcat/catalog.py

@@ -21,7 +21,7 @@ from elasticsearch_dsl import Q
 
 from nomad import search
 
-from .api import api, arg_parser, rdf_respose
+from .api import api, arg_parser, rdf_respose, response_types
 from .mapping import Mapping
 
 ns = api.namespace('catalog', description='The API for DCAT catalog.')
@@ -39,13 +39,13 @@ arg_parser.add_argument(
 class Catalog(Resource):
     @api.doc('get_dcat_datasets')
     @api.expect(arg_parser)
-    @api.produces(['application/xml'])
+    @api.representation('application/xml')
+    @api.produces(response_types)
     @api.response(404, 'There is no entry with the given id.')
     @api.response(401, 'This entry is not publically accessible.')
     @api.response(200, 'Data send', headers={'Content-Type': 'application/xml'})
     def get(self):
         ''' Returns a page of DCAT datasets. '''
-
         args = arg_parser.parse_args()
         modified_since = args.get('modified_since', None)
         after = args.get('after', '')

nomad/app/dcat/datasets.py

@@ -20,7 +20,7 @@ from elasticsearch.exceptions import NotFoundError
 
 from nomad import search
 
-from .api import api, arg_parser, rdf_respose
+from .api import api, arg_parser, rdf_respose, response_types
 from .mapping import Mapping
 
 ns = api.namespace('datasets', description='The API for DCAT datasets.')
@@ -30,7 +30,8 @@ ns = api.namespace('datasets', description='The API for DCAT datasets.')
 class Dataset(Resource):
     @api.doc('get_dcat_dataset')
     @api.expect(arg_parser)
-    @api.produces(['application/xml'])
+    @api.representation('application/xml')
+    @api.produces(response_types)
     @api.response(404, 'There is no entry with the given id.')
     @api.response(401, 'This entry is not publically accessible.')
     @api.response(200, 'Data send', headers={'Content-Type': 'application/xml'})