A project for running Graphene on top of Tornado for Python 3. The codebase was originally a port of graphene-django.
Create a Tornado application and add the GraphQL handlers:
import tornado.web
from tornado.ioloop import IOLoop
from graphene_tornado.schema import schema
from graphene_tornado.tornado_graphql_handler import TornadoGraphQLHandler
class ExampleApplication(tornado.web.Application):
def __init__(self):
handlers = [
(r'/graphql', TornadoGraphQLHandler, dict(graphiql=True, schema=schema)),
(r'/graphql/batch', TornadoGraphQLHandler, dict(graphiql=True, schema=schema, batch=True)),
(r'/graphql/graphiql', TornadoGraphQLHandler, dict(graphiql=True, schema=schema))
]
tornado.web.Application.__init__(self, handlers)
if __name__ == '__main__':
app = ExampleApplication()
app.listen(5000)
IOLoop.instance().start()
When writing your resolvers, decorate them with either Tornado's @coroutine
decorator for Python 2.7:
@gen.coroutine
def resolve_foo(self, info):
foo = yield db.get_foo()
raise Return(foo)
Or use the async
/ await
pattern in Python 3:
async def resolve_foo(self, info):
foo = await db.get_foo()
return foo
graphene-tornado
supports server-side extensions like Apollo Server. The extensions go a step further than Graphene middleware to allow for finer grained interception of request processing. The canonical use case is for tracing; see graphene_tornado/apollo_engine_reporting/engine_agent.py
for an example.
Extensions are experimental and most likely will change in future releases as they should be extensions provided by
graphql-server-core
.
You can integrate with Apollo Engine Reporting by enabling the extension.
$ pip install graphene-tornado[apollo-engine-reporting]
engine_options = EngineReportingOptions()
agent = EngineReportingAgent(engine_options, generate_schema_hash(schema))
class ExampleEngineReportingApplication(tornado.web.Application):
def __init__(self):
engine_extension = lambda: EngineReportingExtension(engine_options, agent.add_trace)
handlers = [
(r'/graphql', TornadoGraphQLHandler, dict(graphiql=True, schema=schema, extensions=[engine_extension])),
(r'/graphql/batch', TornadoGraphQLHandler, dict(graphiql=True, schema=schema, batch=True,
extensions=[engine_extension])),
(r'/graphql/graphiql', TornadoGraphQLHandler, dict(graphiql=True, schema=schema,
extensions=[engine_extension]))
]
tornado.web.Application.__init__(self, handlers)
ENGINE_API_KEY=<your engine API key here> python -m examples.apollo_engine_reporting_example
Then visit https://localhost:5000/graphql/graphiql
, make some queries, and view the results in Apollo Engine.
You can also use OpenCensus for tracing:
$ pip install graphene-tornado[opencensus]
class ExampleOpenCensusApplication(tornado.web.Application):
def __init__(self):
extension = lambda: OpenCensusExtension()
handlers = [
(r'/graphql', TornadoGraphQLHandler, dict(graphiql=True, schema=schema, extensions=[extension])),
(r'/graphql/batch', TornadoGraphQLHandler, dict(graphiql=True, schema=schema, batch=True)),
]
tornado.web.Application.__init__(self, handlers)