Tentative fix for SPARQL query.

lakesuperior/endpoints/query.py

@@ -1,3 +1,5 @@
+import logging
+
 from flask import Blueprint, current_app, request, render_template
 from rdflib.plugin import PluginException
 
@@ -10,6 +12,7 @@ from lakesuperior.store_layouts.ldp_rs.lmdb_store import LmdbStore, TxnManager
 # binary comparisons should be added. Binary lookups—maybe?
 # N.B All data sources are read-only for this endpoint.
 
+logger = logging.getLogger(__name__)
 
 query = Blueprint('query', __name__)
 
@@ -48,6 +51,7 @@ def sparql():
     if request.method == 'GET':
         return render_template('sparql_query.html', nsm=nsm)
     else:
+        logger.debug('Query: {}'.format(request.form['query']))
         store = current_app.rdfly.store
         with TxnManager(store) as txn:
             qres = QueryEngine().sparql_query(request.form['query'])

lakesuperior/store_layouts/ldp_rs/lmdb_store.py

@@ -302,10 +302,13 @@ class LmdbStore(Store):
         '''
         Return length of the dataset.
         '''
+        import pdb; pdb.set_trace()
         if context == self:
             context = None
+        if isinstance(context, Graph):
+            context = context.identifier
 
-        if context.identifier is not None:
+        if context is not None:
             #dataset = self.triples((None, None, None), context)
             with self.cur('c:spo') as cur:
                 if cur.set_key(self._to_key(context)):
@@ -542,6 +545,7 @@ class LmdbStore(Store):
         Where the contexts generator lists all context that the triple appears
         in.
         '''
+        #import pdb; pdb.set_trace()
         #logger.debug('Getting triples for pattern: {} and context: {}'.format(
         #    triple_pattern, context))
         # This sounds strange, RDFLib should be passing None at this point,
@@ -552,7 +556,6 @@ class LmdbStore(Store):
         if isinstance(context, Graph):
             context = context.identifier
             logger.debug('Converted graph into URI: {}'.format(context))
-        import pdb; pdb.set_trace()
         with self.cur('spo:c') as cur:
             for spok in self._triple_keys(triple_pattern, context):
                 if context is not None:
@@ -621,17 +624,25 @@ class LmdbStore(Store):
         '''
         Get a list of all contexts.
 
-        @return generator:URIRef
+        @return generator(Graph)
         '''
-        if triple:
+        import pdb; pdb.set_trace()
+        if triple and any(triple):
             with self.cur('spo:c') as cur:
                 cur.set_key(self._to_key(triple))
-                for ctx in cur.iternext_dup():
-                    yield Graph(identifier=self._from_key(ctx)[0])
+                i = cur.iternext_dup()
         else:
             with self.cur('c:') as cur:
-                for ctx in cur.iternext(values=False):
-                    yield Graph(identifier=self._from_key(ctx)[0])
+                i = cur.iternext(values=False)
+
+        for ck in i:
+            gr_uri = self._from_key(ck)[0]
+            gr = Graph(identifier=graph_uri)
+            for trp in self.triples((None, None, None), gr_uri):
+                gr.add(trp)
+
+            yield gr
+
 
 
     def add_graph(self, graph):
@@ -649,6 +660,7 @@ class LmdbStore(Store):
 
         @param graph (URIRef) URI of the named graph to add.
         '''
+        #import pdb; pdb.set_trace()
         if isinstance(graph, Graph):
             graph = graph.identifier
         pk_c = self._pickle(graph)