Lenient PATCH to match Fedora behavior expected by Hyrax (partial solution).

doc/notes/fcrepo4_deltas.md

@@ -134,7 +134,7 @@ Clients are encouraged to omit LDP types in PUT, POST and PATCH requests.
 ### Lenient handling
 
 FCREPO4 requires server-managed triples to be expressly indicated in a PUT
-request, unless the `Prefer` heeader is set to
+request, unless the `Prefer` header is set to
 `handling=lenient; received="minimal"`, in which case the RDF payload must not
 have any server-managed triples.
 

lakesuperior/model/ldp_rs.py

@@ -49,8 +49,9 @@ class LdpRs(Ldpr):
 
         @param update_str (string) SPARQL-Update staements.
         '''
-        self.handling = 'strict'
+        self.handling = 'lenient' # FCREPO does that and Hyrax requires it.
         local_update_str = g.tbox.localize_ext_str(update_str, self.urn)
+        self._logger.debug('Local update string: {}'.format(local_update_str))
 
         return self._sparql_update(local_update_str)
 
@@ -88,6 +89,10 @@ class LdpRs(Ldpr):
         if notify and current_app.config.get('messaging'):
             self._send_msg(self.RES_UPDATED, check_del_gr, check_ins_gr)
 
+        # @FIXME Ugly workaround until we find how to recompose a SPARQL query
+        # string from a parsed query object.
+        self.rdfly.clear_smt(self.uid)
+
         return self.RES_UPDATED
 
 

lakesuperior/model/ldpr.py

@@ -107,18 +107,27 @@ class Ldpr(metaclass=ABCMeta):
     RES_DELETED = '_delete_'
     RES_UPDATED = '_update_'
 
+    # RDF Types that populate a new resource.
     base_types = {
         nsc['fcrepo'].Resource,
         nsc['ldp'].Resource,
         nsc['ldp'].RDFSource,
     }
 
+    # Predicates that do not get removed when a resource is replaced.
     protected_pred = (
         nsc['fcrepo'].created,
         nsc['fcrepo'].createdBy,
         nsc['ldp'].contains,
     )
 
+    # Server-managed RDF types ignored in the RDF payload if the resource is
+    # being created. N.B. These still raise an error if the resource exists.
+    smt_allow_on_create = {
+        nsc['ldp'].DirectContainer,
+        nsc['ldp'].IndirectContainer,
+    }
+
     _logger = logging.getLogger(__name__)
 
 
@@ -787,6 +796,8 @@ class Ldpr(metaclass=ABCMeta):
     def _check_mgd_terms(self, gr):
         '''
         Check whether server-managed terms are in a RDF payload.
+
+        @param gr (rdflib.Graph) The graph to validate.
         '''
         offending_subjects = set(gr.subjects()) & srv_mgd_subjects
         if offending_subjects:
@@ -798,6 +809,7 @@ class Ldpr(metaclass=ABCMeta):
                     gr.remove((s, None, None))
 
         offending_predicates = set(gr.predicates()) & srv_mgd_predicates
+        # Allow some predicates if the resource is being created.
         if offending_predicates:
             if self.handling=='strict':
                 raise ServerManagedTermError(offending_predicates, 'p')
@@ -807,6 +819,8 @@ class Ldpr(metaclass=ABCMeta):
                     gr.remove((None, p, None))
 
         offending_types = set(gr.objects(predicate=RDF.type)) & srv_mgd_types
+        if not self.is_stored:
+            offending_types -= self.smt_allow_on_create
         if offending_types:
             if self.handling=='strict':
                 raise ServerManagedTermError(offending_types, 't')

lakesuperior/store_layouts/ldp_rs/rsrc_centric_layout.py

@@ -11,6 +11,8 @@ from rdflib.term import Literal
 
 from lakesuperior.dictionaries.namespaces import ns_collection as nsc
 from lakesuperior.dictionaries.namespaces import ns_mgr as nsm
+from lakesuperior.dictionaries.srv_mgd_terms import  srv_mgd_subjects, \
+        srv_mgd_predicates, srv_mgd_types
 from lakesuperior.exceptions import (InvalidResourceError,
         ResourceNotExistsError, TombstoneError, PathSegmentError)
 
@@ -473,6 +475,21 @@ class RsrcCentricLayout:
         self.ds.graph(PTREE_GR_URI).delete((nsc['fcres'][uid], None, None))
 
 
+    def clear_smt(self, uid):
+        '''
+        This is an ugly way to deal with lenient SPARQL update statements
+        that may insert server-managed triples into a user graph.
+
+        @TODO Deprecate when a solution to provide a sanitized SPARQL update
+        sring is found.
+        '''
+        gr = self.ds.graph(nsc['fcmain'][uid])
+        for p in srv_mgd_predicates:
+            gr.remove((None, p, None))
+        for t in srv_mgd_types:
+            gr.remove((None, RDF.type, t))
+
+
     ## PROTECTED MEMBERS ##
 
     def _check_rsrc_status(self, rsrc):