# aiohttp-extracts
This library allows you to extract variable number of request parameters to a handler's arguments.
It uses type hints to determine where each value must be extracted from.
## For example
With aiohttp-extracts:
```python3
from aiohttp import web
from aiohttp_extracts import with_extraction
from aiohttp_extracts import RequestAttr, MatchInfo, QueryAttr
routes = web.RouteTableDef()
@routes.get(r'/chats/{chat_id:(\d+)}/')
@with_extraction
async def handler(
user: RequestAttr[int], # by default it uses argument name
chat: MatchInfo['chat_id', int], # but you can specify name what you want
offset: QueryAttr[int] = 0, # and you can simply set a default value
count: QueryAttr[int] = 100
) -> web.Response:
...
```
Without aiohttp-extracts:
```python3
from aiohttp import web
from aiohttp_extracts import with_extraction
routes = web.RouteTableDef()
@routes.get(r'/chats/{chat_id:(\d+)}/')
async def handler(request: web.Request):
user = request.get('user')
chat = request.match_info.get('chat_id')
offset = request.query.get('offset', 0)
count = request.query.get('count', 100)
) -> web.Response:
...
```
## Installation
Installation process as simple as:
$ pip install aiohttp-extracts
## Usage
First we need to set a middleware to app.
```python3
from aiohttp import web
from aioservertiming import server_timing_mware
app = web.Applicalion(
middlewares = [
server_timing_mware
]
)
```
### Usual handler
```python3
from aiohttp import web
from aiohttp_extracts import with_extraction
from aiohttp_extracts import RequestAttr, MatchInfo, QueryAttr
@with_extraction
async def handler(
user: RequestAttr[int],
chat: MatchInfo['chat_id', int],
offset: QueryAttr[int] = 0,
count: QueryAttr[int] = 100
) -> web.Response:
...
```
### Classview
#### With decorator
```python3
from aiohttp import web
from aiohttp_extracts import with_extraction
from aiohttp_extracts import RequestAttr, MatchInfo, QueryAttr
@extract_classview
class ChatView(web.View):
async def get(
user: RequestAttr[int],
chat: MatchInfo['chat_id', int],
offset: QueryAttr[int] = 0,
count: QueryAttr[int] = 100
) -> web.Response:
...
```
#### With metaclass
```python3
from aiohttp import web
from aiohttp_extracts import ExtractionMeta
from aiohttp_extracts import RequestAttr, MatchInfo, QueryAttr
class ChatView(web.View, metaclass=ExtractionMeta):
async def get(
user: RequestAttr[int],
chat: MatchInfo['chat_id', int],
offset: QueryAttr[int] = 0,
count: QueryAttr[int] = 100
) -> web.Response:
...
```
## Types that can be used in handlers args
| Type name | What it replaces | Additional info |
|:----------|:-----------------|:---------------:|
| aiohttp.web.Request | request | Usually request object |
| aiohttp_extracts.RequestAttr | request.get(...) | Any request attribute |
| aiohttp_extracts.MatchInfo | request.match_info.get(...) | |
| aiohttp_extracts.QueryAttr | request.query.get(...) | |
| aiohttp_extracts.Header | request.headers.get(...) | |
| aiohttp_extracts.Cookie | request.cookies.get(...) | |
| aiohttp_extracts.JSONBody | await request.json() | |
## Links
This library on [PyPI](https://pypi.org/project/aioservertiming/)
