tartiflette-aiohttp 0.6.2

Runs a Tartiflette GraphQL Engine through aiohttp


**tartiflette-aiohttp** is a wrapper of `aiohttp` which includes the Tartiflette GraphQL Engine. You can take a look at the [Tartiflette API documentation](https://tartiflette.io/docs/welcome/what-is-tartiflette).

## Usage

```python
# main.py
from aiohttp import web
from tartiflette import Resolver
from tartiflette_aiohttp import register_graphql_handlers

@Resolver("Query.hello")
async def resolver_hello(parent, args, ctx, info):
return "hello " + args["name"]

sdl = """
type Query {
hello(name: String): String
}
"""

web.run_app(
register_graphql_handlers(
web.Application(),
engine_sdl=sdl
)
)
```

Save the file and start the server.

```bash
$ python main.py
======== Running on http://0.0.0.0:8080 ========
(Press CTRL+C to quit)
```

> Note: The server will be listening on the `/graphql` path by default.

Send a request to your server
```
curl -v -d '{"query": "query { hello(name: "Chuck") }"}' -H "Content-Type: application/json" http://localhost:8080/graphql
```

## Installation

`tartiflette-aiohttp` is available on [pypi.org](https://pypi.org/project/tartiflette-aiohttp/).

**WARNING**: Do not forget to install the [tartiflette dependencies beforehand as explained in the tutorial](https://tartiflette.io/docs/tutorial/install-tartiflette/).

```bash
pip install tartiflette-aiohttp
```

## How to use

### Use with built-in Tartiflette Engine

The basic and common way to use Tartiflette with `aiohttp`, is to create an `aiohttp` `web.Application` and use the `register_graphql_handlers` helper to bind Tartiflette and `aiohttp` together. `engine_*` parameters will be forwarded to the built-in [tartiflette](https://github.com/dailymotion/tartiflette) engine instance.

```python
from aiohttp import web
from tartiflette_aiohttp import register_graphql_handlers

sdl = """
type Query {
hello(name: String): String
}
"""

ctx = {
'user_service': user_service
}

web.run_app(
register_graphql_handlers(
app=web.Application(),
engine_sdl=sdl,
engine_schema_name="default",
executor_context=ctx,
executor_http_endpoint='/graphql',
executor_http_methods=['POST', 'GET']
)
)
```

**Parameters**:

* **engine_sdl**: Contains the [Schema Definition Language](https://graphql.org/learn/schema/)
- Can be a string which contains the SDL
- Can be an array of strings, which contain the SDLs
- Can be a path to an SDL
- Can be an array of paths which contain the SDLs
* **engine_schema_name**: Name of the schema used by the built-in engine. Useful for advanced use-cases, see [Schema Registry API](https://tartiflette.io/docs/api/schema-registry).
* **executor_context**: Context which will be passed to each resolver (as a dict). Very useful for passing handlers to services, functions or data that you want to use in your resolvers. The context reference is **unique** per request, a shallow copy is created based on the context passed.
- **req**: Request object from `aiohttp`
- **app**: Application object from `aiohttp`
* **executor_http_endpoint**: Endpoint where the GraphQL Engine will be attached, by default on `/graphql`
* **executor_http_methods**: HTTP Methods where the GraphQL Engine will be attached, by default on **POST** and **GET**.

### Use with custom Tartiflette engine

In the case you already have a Tartiflette Engine instance, or, you do not want to use the built-in instance. You can pass an existing instance to the `register_graphql_handlers` helper.

```python
# main.py
from aiohttp import web
from tartiflette import Resolver, Engine
from tartiflette_aiohttp import register_graphql_handlers

@Resolver("Query.hello")
async def resolver_hello(parent, args, ctx, info):
return "hello " + args["name"]

sdl = """
type Query {
hello(name: String): String
}
"""

engine = Engine(sdl)

ctx = {
'user_service': user_service
}

web.run_app(
register_graphql_handlers(
app=web.Application(),
engine=engine,
executor_context=ctx,
executor_http_endpoint='/graphql',
executor_http_methods=['POST', 'GET']
)
)
```

**Parameters**:

* **engine**: an instance of the Tartiflette Engine
* **executor_context**: Context which will be passed to each resolver (as a dict). Very useful for passing handlers to services, functions or data that you want to use in your resolvers.
- **req**: Request object from `aiohttp`
- **app**: Application object from `aiohttp`
* **executor_http_endpoint**: Endpoint where the GraphQL Engine will be attached, by default on `/graphql`
* **executor_http_methods**: HTTP Methods where the GraphQL Engine will be attached, by default on **POST** and **GET**

### Tartiflette with subscriptions

Tartiflette embeds an easy way to deal with subscriptions. The only thing to do is
to fill in the `subscription_ws_endpoint` parameter and everything will work out
of the box with `aiohttp` WebSockets. You can see a full example
[here](examples/aiohttp/dogs).

### Enable GraphiQL handler

Tartiflette allows you to set up an instance of GraphiQL easily to quickly test
your queries. The easiest way to do that is to set the `graphiql_enabled`
parameter to `True`. Then, you can customize your GraphiQL instance by filling
the `graphiql_options` parameter as bellow:

```python
from aiohttp import web

from tartiflette_aiohttp import register_graphql_handlers


_SDL = """
type Query {
hello(name: String): String
}
"""

web.run_app(
register_graphql_handlers(
app=web.Application(),
engine_sdl=_SDL,
graphiql_enabled=True,
graphiql_options={ # This is optional
"endpoint": "/explorer", # Default: `/graphiql`,
"default_query": """
query Hello($name: String) {
hello(name: $name)
}
""",
"default_variables": {
"name": "Bob",
},
"default_headers": {
"Authorization": "Bearer <default_token>",
},
},
)
)
```

**Parameters**:

* **engine_sdl**: Contains the [Schema Definition Language](https://graphql.org/learn/schema/)
- Can be a string which contains the SDL
- Can be an array of strings, which contain the SDLs
- Can be a path to an SDL
- Can be an array of paths which contain the SDLs
* **graphiql_enabled** *(Optional[bool] = False)*: Determines whether or not we should include a GraphiQL interface
* **graphiql_options** *(Optional[dict] = None)*: Customization options for the GraphiQL instance:
- **endpoint** *(Optional[str] = "/graphiql")*: allows to customize the GraphiQL interface endpoint path
- **default_query** *(Optional[str] = None)*: allows you to pre-fill the GraphiQL interface with a default query
- **default_variables** *(Optional[dict] = None)*: allows you to pre-fill the GraphiQL interface with default variables
- **default_headers** *(Optional[dict] = None)*: allows you to add default headers to each request sent through the GraphiQL instance