Graphene - sgml/signature GitHub Wiki

WebDav Comparison

Dimension	WebDAV	GraphQL
Era & Philosophy	Late 1990s; extend HTTP for remote file manipulation	2015+; client-driven data querying and shaping
Primary Use Case	File system abstraction over HTTP	Structured data querying and mutation
Transport Protocol	HTTP (with verbs like PROPFIND, MKCOL, LOCK)	HTTP (usually POST for queries/mutations)
Statefulness	Stateful; uses locks and persistent resources	Stateless; relies on client context and schema
Auditability	Medium; relies on HTTP logs and lock tracking	High; query logs and resolver traces are inspectable
Ambiguity Zones	Locking semantics, partial updates, depth headers	Over-fetching/under-fetching, resolver side effects
Extensibility	Limited; fixed verbs and XML-based payloads	High; schema evolves with types, fields, resolvers
Error Handling	Verbose; uses HTTP status codes and XML bodies	Structured; errors returned in query response
Security Surface	Broad; includes file access, locking, and overwrite	Narrower; focused on query validation and auth
Caching Semantics	Poor; hard to cache due to stateful operations	Good; query results can be cached per shape
Developer Ergonomics	Complex; XML payloads, custom verbs, lock handling	High; introspection, tooling, and type safety
Tooling Ecosystem	Sparse; mostly legacy clients and OS integrations	Rich; IDE plugins, schema explorers, mock servers
Legacy Risk	Low; strong native OS support across Windows/macOS/Linux	Medium; requires custom server and tooling layers
Operational Model	File-centric; maps to folders, files, and metadata	Data-centric; maps to entities, fields, and queries
Coupling to DB Query Language	Low; operates independently of SQL or query layers	High; resolvers often wrap SQL/ORM or NoSQL queries
DokuWiki Integration Complexity	Low; aligns with flat-file access and page structure	High; requires custom resolvers for file-based parsing
Leaky Abstraction Risk	Medium; exposes HTTP quirks, lock state, depth headers	High; resolver logic often leaks DB schema, joins, and pagination quirks

Middleware

import graphene

# Define a logging middleware
class LoggingMiddleware:
    def resolve(self, next_, root, info, **args):
        field = info.field_name
        print(f"[⏳] Resolving field: {field}")
        result = next_(root, info, **args)
        print(f"[✅] Resolved field: {field}")
        return result

# Sample schema
class Query(graphene.ObjectType):
    hello = graphene.String()

    def resolve_hello(self, info):
        return "Hello from Graphene"

schema = graphene.Schema(query=Query, middleware=[LoggingMiddleware()])

Explanation

Absolutely! In Graphene, you can wrap a resolver using custom middleware to add cross-cutting behavior—like logging, authorization checks, or even performance monitoring—around your field resolution.

Here’s a minimal but practical example of **wrapping a resolver** with middleware:

---

### 🧩 Example: Logging Resolver Middleware

```python
import graphene

# Define a logging middleware
class LoggingMiddleware:
    def resolve(self, next_, root, info, **args):
        field = info.field_name
        print(f"[⏳] Resolving field: {field}")
        result = next_(root, info, **args)
        print(f"[✅] Resolved field: {field}")
        return result

# Sample schema
class Query(graphene.ObjectType):
    hello = graphene.String()

    def resolve_hello(self, info):
        return "Hello from Graphene"

schema = graphene.Schema(query=Query, middleware=[LoggingMiddleware()])

resolve() wraps every resolver call.
You can inspect the field name, arguments, context (info.context), etc.
It allows injection of behavior before and after resolver execution.

Graphene supports composing them via MiddlewareManager.


## Query Validators
Standard query validators can be used to test enforcement of security best practices such as the enforcement of a maximum depth for any operation in a GraphQL document or verifying that your schema cannot be introspected.

* Create a function:

def resolve_bar(


* Create a field:

bar = graphene.Field(schema.foo)

Translates to

foo{ bar{} }

* Create variables

baz=graphene.String(required=True)


Translates to

baz:String!


```term=graphene.String(required=False)```

Translates to 

```baz:String```

## SQLAlchemy => Flask => Pytest Process Map

steps:

name: "Set Up Your Environment" description: "Install necessary packages: graphene, graphene-sqlalchemy, and SQLAlchemy." commands:
- "pip install graphene graphene-sqlalchemy sqlalchemy"
name: "Define SQLAlchemy Model for Foo" description: "Create an SQLAlchemy model corresponding to the table 'foo'." code: |

models.py

from sqlalchemy import Column, Integer, String from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class FooModel(Base): tablename = 'foo' id = Column(Integer, primary_key=True) name = Column(String) value = Column(Integer)
name: "Create Graphene SQLAlchemy Object Type" description: "Define a Graphene type for Foo using SQLAlchemyObjectType based on FooModel." code: |

schema.py (part 1)

import graphene from graphene_sqlalchemy import SQLAlchemyObjectType from models import FooModel

class Foo(SQLAlchemyObjectType): class Meta: model = FooModel
name: "Extend GraphQL Schema with 'paginate_foo'" description: > Add a query field 'paginate_foo' to the Query type that accepts 'limit' and 'offset' as required arguments, and implement its resolver to execute the SQLAlchemy query with LIMIT and OFFSET. code: |

schema.py (continued)

class Query(graphene.ObjectType): paginate_foo = graphene.List( Foo, limit=graphene.Int(required=True), offset=graphene.Int(required=True) )
```
  def resolve_paginate_foo(self, info, limit, offset):
      # Retrieve the SQLAlchemy session from the context
      session = info.context.get("session")
      # Execute the SQL query with pagination
      results = session.query(FooModel).limit(limit).offset(offset).all()
      return results
```
Create the Graphene schema

schema = graphene.Schema(query=Query)
name: "Integrate with GraphQL Server using Flask" description: > Set up a Flask-based GraphQL server that wires in the Graphene schema and passes the SQLAlchemy session into the GraphQL context. This ensures that your resolver can access the database. code: |

app.py

from flask import Flask, request from flask_graphql import GraphQLView from sqlalchemy import create_engine from sqlalchemy.orm import sessionmaker from schema import schema # the schema defined above

app = Flask(name)

Configure the database engine and session factory

engine = create_engine('sqlite:///mydatabase.db') # Replace with your actual DB URI SessionLocal = sessionmaker(bind=engine)

@app.before_request def create_session(): request.session = SessionLocal()

@app.teardown_request def remove_session(exception=None): session = getattr(request, 'session', None) if session: session.close()

app.add_url_rule( '/graphql', view_func=GraphQLView.as_view( 'graphql', schema=schema, graphiql=True, get_context=lambda: {"session": request.session} ) )

if name == 'main': app.run(debug=True)
name: "Test GraphQL Query using GraphiQL" description: > Verify your GraphQL endpoint by running a query in GraphiQL (or another GraphQL client) to ensure that pagination is working as expected. example_query: | query { paginate_foo(limit: 10, offset: 0) { id name value } }
name: "Pytest Mocking of Resolver" description: > Create a pytest unit test that mocks the SQLAlchemy session to test the 'paginate_foo' resolver. This step verifies that the resolver correctly processes the 'limit' and 'offset' parameters and returns an expected list of Foo objects. code: |

test_resolvers.py

import pytest from schema import Query from models import FooModel

class DummySession: def init(self, results): self.results = results
```
  def query(self, model):
      assert model == FooModel
      return self

  def limit(self, limit):
      self._limit = limit
      return self

  def offset(self, offset):
      self._offset = offset
      return self

  def all(self):
      return self.results
```
@pytest.fixture def dummy_session(): # Create dummy FooModel objects simulating database rows foo1 = FooModel(id=1, name="Foo 1", value=100) foo2 = FooModel(id=2, name="Foo 2", value=200) return DummySession(results=[foo1, foo2])

def test_paginate_foo(dummy_session): context = {"session": dummy_session} # Dummy info object with a context attribute class DummyInfo: context = context
```
  query = Query()
  result = query.resolve_paginate_foo(info=DummyInfo(), limit=10, offset=0)
  # Assert the correct number of Foo objects and their values
  assert len(result) == 2
  assert result[0].id == 1
  assert result[0].name == "Foo 1"
  assert result[1].id == 2
  assert result[1].name == "Foo 2"
```


## Graphene vs Apollo

graphene: contributors: 180 releases: 60 open_issues: 200 pull_requests: 1500 commits: 3000 tests: 42 number_of_licenses: 1 number_of_repositories_tagged_with_this_topic: 31 known_bugs: 200 forks: 823 readme_size_bytes: 5120 number_of_original_authors: 1 number_of_unimplemented_specification_items: 3 number_of_files_in_repo: 320

apollo: contributors: 400 releases: 100 open_issues: 1000 pull_requests: 5000 commits: 10000 tests: 210 number_of_licenses: 2 number_of_repositories_tagged_with_this_topic: 460 known_bugs: 1000 forks: 2500 readme_size_bytes: 8192 number_of_original_authors: 4 number_of_unimplemented_specification_items: 1 number_of_files_in_repo: 980

## Tools

| Tool | Description | Link |
|------|-------------|------|
| **GraphQL Inspector** | A dedicated GraphQL validation tool for schema changes, breaking changes detection, and security analysis. | [GraphQL Inspector](https://www.scrumlaunch.com/blog/best-graphql-tools-for-2025/) |
| **GraphQL Editor** | A visual GraphQL schema builder and testing tool, designed for API visualization and debugging. | [GraphQL Editor](https://dev.to/requestly/best-tools-for-graphql-development-in-2025-dba) |
| **GraphQL Faker** | A tool for generating mock GraphQL data, useful for testing and prototyping GraphQL APIs. | [GraphQL Faker](https://apidog.com/blog/best-graphql-tools/) |


## References

https://github.com/graphql/graphql-spec

https://docs.graphene-python.org/en/latest/types/interfaces/

https://medium.com/@ryk.kiel/graphql-and-fastapi-the-ultimate-combination-for-building-apis-with-python-f4391bf5505c

https://docs.graphene-python.org/en/latest/_modules/graphene/types/scalars/#Boolean

https://github.com/graphql-python/swapi-graphene/blob/master/starwars/schema.py

https://github.com/graphql-python/graphene/issues/268

https://buildmedia.readthedocs.org/media/pdf/graphene-python/stable/graphene-python.pdf

https://readthedocs.org/projects/graphene-python/downloads/pdf/stable/

https://docs.graphene-python.org/en/latest/types/mutations/

https://github.com/graphql-python/graphene

https://vincenttechblog.com/building-web-api-with-python-flask-graphql-sqlalchemy-and-postgresql/

https://stackoverflow.com/questions/57313080/perform-nested-query-in-python-graphene-with-distinct-types-in-schema

https://matthewgladney.com/blog/data/graphql/adding-to-a-graphene-schema-to-execute-a-graphql-query/

https://github.com/graphql-python/graphene-django/issues/142

https://pypi.org/project/graphene/

https://docs.graphene-python.org/projects/sqlalchemy/en/latest/

https://shopify.dev/docs/api/usage/pagination-graphql

https://shopify.dev/docs/apps/build/graphql

https://shopify.dev/docs/api/admin-graphql
https://serverless.com/blog/running-scalable-reliable-graphql-endpoint-with-serverless/

https://jeffersonheard.github.io/python/graphql/2018/12/08/graphene-python.html

https://docs.graphene-python.org/en/latest/quickstart/

https://github.com/graphql-python/graphene/issues/110

https://itnext.io/python-graphql-tips-tricks-and-performance-improvements-beede1f4adb6

https://github.com/graphql-python/graphene-sqlalchemy/blob/master/docs/tutorial.rst

https://medium.com/free-code-camp/how-to-develop-a-flask-graphql-graphene-mysql-and-docker-starter-kit-4d475f24ee76

https://stackoverflow.com/questions/46415795/how-to-place-a-multi-line-single-string-json-in-postman/60083076#60083076

https://stackoverflow.com/questions/60115681/python-multiline-graphql-mutation-with-variables-keyerror

https://stackoverflow.com/questions/62384215/best-way-to-construct-a-graphql-query-string-in-python

https://stackoverflow.com/search?q=graphql+python+%22multiline%22

https://www.couchbase.com/blog/using-graphql-with-golang-and-a-nosql-database/

https://neo4j.com/blog/developer/spring-graphql-neo4j/

https://developer.ibm.com/tutorials/awb-accessing-mongodb-using-graphql-interface/

https://developer.ibm.com/articles/awb-how-to-write-graphql-queries/

https://news.ycombinator.com/item?id=40981850

https://news.ycombinator.com/item?id=32368616

https://news.ycombinator.com/item?id=31284846

https://news.ycombinator.com/item?id=37078606

https://news.ycombinator.com/item?id=26226001

https://www.youtube.com/watch?v=iDqgMbPSUYs

Graphene - sgml/signature GitHub Wiki

WebDav Comparison

Middleware

Explanation

models.py

schema.py (part 1)

schema.py (continued)

Create the Graphene schema

app.py

Configure the database engine and session factory

test_resolvers.py