first attempt for dynamic datalink

daiquiri/datalink/adapter.py

@@ -7,7 +7,7 @@
 from daiquiri.core.constants import ACCESS_LEVEL_PUBLIC
 from daiquiri.core.utils import get_doi_url, import_class
 
-from .constants import DATALINK_RELATION_TYPES
+from .constants import DATALINK_RELATION_TYPES, DATALINK_FIELDS
 from .models import Datalink
 
 
@@ -30,6 +30,14 @@ class BaseDatalinkAdapter(object):
     * get_<resource_type>_links(self, resource): returns a resource into a list
       of rows of the datalink table (list of python dicts)
 
+    There are two further adapters, which do not declare resources:
+
+    * DynamicDatalinkAdapter: the latter does not declare a resource, but will inject on the fly 
+      extra datalink entries according to the method: get_dyn_datalink_links()
+
+    * QueryJobDatalinkAdapterMixin: The latter does not declare a resource either, but it injects 
+      extra context information for the datalink viewer.
+
     See the mixins below for an example.
     """
 
@@ -56,14 +64,38 @@ def get_links(self, resource_type, resource):
         return getattr(self, 'get_%s_links' % resource_type)(resource)
 
     def get_context_data(self, request, **kwargs):
+        '''Get the datalink related context data for a given request
+        '''
         context = {}
 
         if 'ID' in kwargs:
-            context['datalinks'] = Datalink.objects.filter(ID=kwargs['ID']).order_by('semantics')
+            field_names = [field['name'] for field in DATALINK_FIELDS]
+            # more precise would be to use a serializer instead of list(QuerySet.values())
+            context['datalinks'] = list(Datalink.objects.filter(ID=kwargs['ID']).order_by('semantics').values())
             context['ID'] = kwargs['ID']
 
         return context
 
+    def get_datalink_rows(self, identifiers, **kwargs):
+        '''Get the list of datalink entries for the provided identifiers
+        '''
+
+        # get the datalink entries from Datalink Table and metadata (Table and Schema)
+        field_names = [field['name'] for field in DATALINK_FIELDS]
+        rows = list(Datalink.objects.filter(ID__in=identifiers).values_list(*field_names))
+
+        # get the dynamic datalink entries
+        dyn_rows = [tuple(link.values()) for link in self.get_dyn_datalink_links(identifiers)]
+        rows = rows + dyn_rows
+
+        # check for missing IDs and return error message
+        for identifier in identifiers:
+            if not any(filter(lambda row: row[0] == identifier, rows)):
+                rows.append((identifier, None, None, 'NotFoundFault: {}'.format(identifier), None, None, None, None))        
+
+        return rows
+
+
 
 class TablesDatalinkAdapterMixin(object):
     '''
@@ -226,6 +258,29 @@ def get_table_links(self, table):
         return table_links
 
 
+class DynamicDatalinkAdapterMixin(object):
+    '''Define the interface to dynamically add datalink entries
+    '''
+
+    def get_dyn_datalink_links(self, IDs, **kwargs):
+        '''No dynamically generated entries. Can be overwriten.
+
+        this method should return a list of dict with the following keys:
+             ID, access_url, service_def, error_message, description, semantics, content_type, content_length
+        '''
+        return([])
+
+    def get_context_data(self, request, **kwargs):
+        '''Inject dynamically generated Datalink entries into the context for the daiquiri.datalinks.views.datalink View
+        '''
+        context = super().get_context_data(request, **kwargs)
+
+        if 'ID' in kwargs:
+            context['datalinks'] = context['datalinks'] + self.get_dyn_datalink_links([kwargs['ID']], **kwargs)
+
+        return context
+
+
 class QueryJobDatalinkAdapterMixin(object):
     '''
     Injects the query job into the context data for the daiquiri.datalinks.views.datalink view
@@ -244,8 +299,8 @@ def get_context_data(self, request, **kwargs):
 
         return context
 
-
-class DefaultDatalinkAdapter(MetadataDatalinkAdapterMixin,
+class DefaultDatalinkAdapter(DynamicDatalinkAdapterMixin,
+                             MetadataDatalinkAdapterMixin,
                              TablesDatalinkAdapterMixin,
                              QueryJobDatalinkAdapterMixin,
                              BaseDatalinkAdapter):

daiquiri/datalink/viewsets.py

@@ -7,11 +7,12 @@
 from daiquiri.core.generators import generate_votable
 
 from .constants import DATALINK_FIELDS, DATALINK_CONTENT_TYPE
-
+from .adapter import DatalinkAdapter
 from .models import Datalink
 
-
 class SyncDatalinkJobViewSet(viewsets.GenericViewSet):
+    '''Generate the datalink VOTable
+    ''' 
 
     def list(self, request):
         return self.perform_sync_job(request, request.GET)
@@ -20,17 +21,14 @@ def create(self, request):
         return self.perform_sync_job(request, request.POST)
 
     def perform_sync_job(self, request, data):
-        rows = []
 
         if 'ID' in data:
             identifiers = data.getlist('ID')
-            field_names = [field['name'] for field in DATALINK_FIELDS]
-            rows = list(Datalink.objects.filter(ID__in=identifiers).values_list(*field_names))
 
-            # check for missing IDs and return error message
-            for identifier in identifiers:
-                if not any(filter(lambda row: row[0] == identifier, rows)):
-                    rows.append((identifier, None, None, 'NotFoundFault: {}'.format(identifier), None, None, None, None))
+        adapter = DatalinkAdapter()
+
+        # get all datalink entries (DatalinkTable, Metadata and Dynamic)
+        rows = adapter.get_datalink_rows(identifiers)
 
         if data.get('RESPONSEFORMAT') == 'application/json':
             return JsonResponse({

daiquiri/oai/adapter.py

@@ -7,6 +7,7 @@
 from daiquiri.core.adapter import DatabaseAdapter
 from daiquiri.core.constants import ACCESS_LEVEL_PUBLIC
 from daiquiri.core.utils import get_doi, import_class
+from daiquiri.datalink.adapter import DatalinkAdapter
 
 
 def OaiAdapter():
@@ -219,21 +220,21 @@ def get_datacite_datalink_serializer_class(self):
         return import_class('daiquiri.datalink.serializers.DataciteSerializer')
 
     def get_datalink_list(self):
-        for table in self.tables:
-            schema_name, table_name = table.split('.')
-            rows = DatabaseAdapter().fetch_rows(schema_name, table_name, column_names=['ID', 'access_url'],
-                                                page_size=0, filters={'semantics': '#doi'})
 
-            for ID, access_url in rows:
+        adapter = DatalinkAdapter()
+        # get all datalink entries: DatalinkTables, Metadata and Dynamic
+        rows = adapter.get_datalink_rows([pk])
+
+        for ID, access_url, _, _, _, semantics, _, _ in rows:
+            if semantics == '#doi':
                 yield 'datalink', {'id': str(ID), 'doi': get_doi(access_url)}
+
 
     def get_datalink(self, pk):
-        rows = []
-        for table in self.tables:
-            schema_name, table_name = table.split('.')
-            rows += DatabaseAdapter().fetch_rows(schema_name, table_name, column_names=[
-                'access_url', 'description', 'semantics', 'content_type', 'content_length'
-            ], filters={'ID': str(pk)})
+
+        adapter = DatalinkAdapter()
+        # get all datalink entries: DatalinkTables, Metadata and Dynamic
+        rows = adapter.get_datalink_rows([pk])
 
         datalink = {
             'formats': [],
@@ -245,7 +246,7 @@ def get_datalink(self, pk):
             ],
             'related_identifiers': []
         }
-        for access_url, description, semantics, content_type, content_length in rows:
+        for _, access_url, _, _, description, semantics, content_type, content_length in rows:
             if semantics == '#doi':
                 datalink['doi'] = get_doi(access_url)
                 datalink['title'] = description