def hydrate(self, data):
""" Hydrate a dictionary of data to produce a :class:`.Node`,
:class:`.Relationship` or other graph object instance. The
data structure and values expected are those produced by the
`REST API <http://neo4j.com/docs/stable/rest-api.html>`__.
:arg data: dictionary of data to hydrate
"""
if isinstance(data, dict):
if "self" in data:
if "type" in data:
return Relationship.hydrate(data)
else:
return Node._find_hydrator(data)
elif "nodes" in data and "relationships" in data:
if "directions" not in data:
from py2neo.batch import Job, Target
node_uris = data["nodes"]
relationship_uris = data["relationships"]
jobs = [Job("GET", Target(uri)) for uri in relationship_uris]
directions = []
for i, result in enumerate(self.batch.submit(jobs)):
rel_data = result.content
start = rel_data["start"]
end = rel_data["end"]
if start == node_uris[i] and end == node_uris[i + 1]:
directions.append("->")
else:
directions.append("<-")
data["directions"] = directions
return Path.hydrate(data)
elif "columns" in data and "data" in data:
from py2neo.cypher import RecordList
return RecordList.hydrate(data, self)
elif "neo4j_version" in data:
return self
elif "exception" in data and ("stacktrace" in data or "stackTrace" in data):
message = data.pop("message", "The server returned an error")
raise GraphError(message, **data)
else:
warn("Map literals returned over the Neo4j REST interface are ambiguous "
"and may be hydrated as graph objects")
return data
elif is_collection(data):
return type(data)(map(self.hydrate, data))
else:
return data
