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import inspect
import json
import re
import six
from django.http import HttpResponse, HttpResponseNotAllowed
from django.http.response import HttpResponseBadRequest
from django.shortcuts import render
from django.utils.decorators import method_decorator
from django.views.generic import View
from django.views.decorators.csrf import ensure_csrf_cookie
from graphql import get_default_backend
from graphql.error import format_error as format_graphql_error
from graphql.error import GraphQLError
from graphql.execution import ExecutionResult
from graphql.type.schema import GraphQLSchema
from .settings import graphene_settings
class HttpError(Exception):
def __init__(self, response, message=None, *args, **kwargs):
self.response = response
self.message = message = message or response.content.decode()
super(HttpError, self).__init__(message, *args, **kwargs)
def get_accepted_content_types(request):
def qualify(x):
parts = x.split(";", 1)
if len(parts) == 2:
match = re.match(r"(^|;)q=(0(\.\d{,3})?|1(\.0{,3})?)(;|$)", parts[1])
if match:
return parts[0].strip(), float(match.group(2))
return parts[0].strip(), 1
raw_content_types = request.META.get("HTTP_ACCEPT", "*/*").split(",")
qualified_content_types = map(qualify, raw_content_types)
return list(
x[0] for x in sorted(qualified_content_types, key=lambda x: x[1], reverse=True)
)
def instantiate_middleware(middlewares):
for middleware in middlewares:
if inspect.isclass(middleware):
yield middleware()
continue
yield middleware
class GraphQLView(View):
graphiql_version = "0.11.10"
graphiql_template = "graphene/graphiql.html"
schema = None
graphiql = False
executor = None
backend = None
middleware = None
root_value = None
pretty = False
batch = False
def __init__(
self,
schema=None,
executor=None,
middleware=None,
root_value=None,
graphiql=False,
pretty=False,
batch=False,
backend=None,
):
if not schema:
schema = graphene_settings.SCHEMA
if backend is None:
backend = get_default_backend()
if middleware is None:
middleware = graphene_settings.MIDDLEWARE
self.schema = self.schema or schema
if middleware is not None:
self.middleware = list(instantiate_middleware(middleware))
self.executor = executor
self.root_value = root_value
self.pretty = self.pretty or pretty
self.graphiql = self.graphiql or graphiql
self.batch = self.batch or batch
self.backend = backend
assert isinstance(
self.schema, GraphQLSchema
), "A Schema is required to be provided to GraphQLView."
assert not all((graphiql, batch)), "Use either graphiql or batch processing"
# noinspection PyUnusedLocal
def get_root_value(self, request):
return self.root_value
def get_middleware(self, request):
return self.middleware
def get_context(self, request):
return request
def get_backend(self, request):
return self.backend
@method_decorator(ensure_csrf_cookie)
def dispatch(self, request, *args, **kwargs):
try:
if request.method.lower() not in ("get", "post"):
raise HttpError(
HttpResponseNotAllowed(
["GET", "POST"], "GraphQL only supports GET and POST requests."
)
)
data = self.parse_body(request)
show_graphiql = self.graphiql and self.can_display_graphiql(request, data)
if show_graphiql:
return self.render_graphiql(
request, graphiql_version=self.graphiql_version
)
if self.batch:
responses = [self.get_response(request, entry) for entry in data]
result = "[{}]".format(
",".join([response[0] for response in responses])
)
status_code = (
responses
and max(responses, key=lambda response: response[1])[1]
or 200
)
else:
result, status_code = self.get_response(request, data, show_graphiql)
return HttpResponse(
status=status_code, content=result, content_type="application/json"
)
except HttpError as e:
response = e.response
response["Content-Type"] = "application/json"
response.content = self.json_encode(
request, {"errors": [self.format_error(e)]}
)
return response
def get_response(self, request, data, show_graphiql=False):
query, variables, operation_name, id = self.get_graphql_params(request, data)
execution_result = self.execute_graphql_request(
request, data, query, variables, operation_name, show_graphiql
)
status_code = 200
if execution_result:
response = {}
if execution_result.errors:
response["errors"] = [
self.format_error(e) for e in execution_result.errors
]
if execution_result.invalid:
status_code = 400
else:
response["data"] = execution_result.data
if self.batch:
response["id"] = id
response["status"] = status_code
result = self.json_encode(request, response, pretty=show_graphiql)
else:
result = None
return result, status_code
def render_graphiql(self, request, **data):
return render(request, self.graphiql_template, data)
def json_encode(self, request, d, pretty=False):
if not (self.pretty or pretty) and not request.GET.get("pretty"):
return json.dumps(d, separators=(",", ":"))
return json.dumps(d, sort_keys=True, indent=2, separators=(",", ": "))
def parse_body(self, request):
content_type = self.get_content_type(request)
if content_type == "application/graphql":
return {"query": request.body.decode()}
elif content_type == "application/json":
# noinspection PyBroadException
try:
body = request.body.decode("utf-8")
except Exception as e:
raise HttpError(HttpResponseBadRequest(str(e)))
try:
request_json = json.loads(body)
if self.batch:
assert isinstance(request_json, list), (
"Batch requests should receive a list, but received {}."
).format(repr(request_json))
assert (
len(request_json) > 0
), "Received an empty list in the batch request."
else:
assert isinstance(
request_json, dict
), "The received data is not a valid JSON query."
return request_json
except AssertionError as e:
raise HttpError(HttpResponseBadRequest(str(e)))
except (TypeError, ValueError):
raise HttpError(HttpResponseBadRequest("POST body sent invalid JSON."))
elif content_type in [
"application/x-www-form-urlencoded",
"multipart/form-data",
]:
return request.POST
return {}
def execute_graphql_request(
self, request, data, query, variables, operation_name, show_graphiql=False
):
if not query:
if show_graphiql:
return None
raise HttpError(HttpResponseBadRequest("Must provide query string."))
try:
backend = self.get_backend(request)
document = backend.document_from_string(self.schema, query)
except Exception as e:
return ExecutionResult(errors=[e], invalid=True)
if request.method.lower() == "get":
operation_type = document.get_operation_type(operation_name)
if operation_type and operation_type != "query":
if show_graphiql:
return None
raise HttpError(
HttpResponseNotAllowed(
["POST"],
"Can only perform a {} operation from a POST request.".format(
operation_type
),
)
)
try:
extra_options = {}
if self.executor:
# We only include it optionally since
# executor is not a valid argument in all backends
extra_options["executor"] = self.executor
return document.execute(
root=self.get_root_value(request),
variables=variables,
operation_name=operation_name,
context=self.get_context(request),
middleware=self.get_middleware(request),
**extra_options
)
except Exception as e:
return ExecutionResult(errors=[e], invalid=True)
@classmethod
def can_display_graphiql(cls, request, data):
raw = "raw" in request.GET or "raw" in data
return not raw and cls.request_wants_html(request)
@classmethod
def request_wants_html(cls, request):
accepted = get_accepted_content_types(request)
accepted_length = len(accepted)
# the list will be ordered in preferred first - so we have to make
# sure the most preferred gets the highest number
html_priority = (
accepted_length - accepted.index("text/html")
if "text/html" in accepted
else 0
)
json_priority = (
accepted_length - accepted.index("application/json")
if "application/json" in accepted
else 0
)
return html_priority > json_priority
@staticmethod
def get_graphql_params(request, data):
query = request.GET.get("query") or data.get("query")
variables = request.GET.get("variables") or data.get("variables")
id = request.GET.get("id") or data.get("id")
if variables and isinstance(variables, six.text_type):
try:
variables = json.loads(variables)
except Exception:
raise HttpError(HttpResponseBadRequest("Variables are invalid JSON."))
operation_name = request.GET.get("operationName") or data.get("operationName")
if operation_name == "null":
operation_name = None
return query, variables, operation_name, id
@staticmethod
def format_error(error):
if isinstance(error, GraphQLError):
return format_graphql_error(error)
return {"message": six.text_type(error)}
@staticmethod
def get_content_type(request):
meta = request.META
content_type = meta.get("CONTENT_TYPE", meta.get("HTTP_CONTENT_TYPE", ""))
return content_type.split(";", 1)[0].lower()