Parameters

Query Strings

You can add a query string parameter to your route via the query decorator:

from view import new_app, query

app = new_app()

@app.get("/hello")
@query("name", str)
async def hello(name: str):
    return p(f"Hello, {name}")

app.run()

The first argument is the name of the parameter in the query string, not the argument name, and the second argument is the type that it should take.

Body

Bodies work the exact same way as queries, but with the body decorator instead:

@app.get("/goodbye")
@body("name", str)
async def goodbye(name: str):
    return p(f"Bye, {name}")

From App

In a case where you have direct access to your App instance (i.e. in manual loading), you don't have to even use body and query, and instead use the app methods instead:

@app.get("/hello")
@app.query("name", str)
async def hello(name: str):
    return f"hello, {name}"

app.query and app.body work exactly the same as @query and @body.

Path

Path parameters are even simpler, just wrap a route part in brackets, like so:

@app.get("/hello/{name}")
async def hello(name: str):
    return p(f"Your name is: {name}")

Now in the browser, if you were to go to /hello/world, the name parameter above would be world.

Here's a more complicated example:

@app.get("/auth/{user_id}/something/{token}")
async def token(user_id: str, token: str):
    # ...
    return p("Successfully authorized!")

Type Validation

view.py will ensure that the type sent to the server is compatible with what you passed to the decorator. For example:

@app.get("/")
@app.query("number", int)
async def index(number: int):
    # number will always be an int.
    # if it isn't, an error 400 is sent back to the user automatically
    return "..."

The following types are supported:

• typing.Any
• str
• int
• bool
• float
• dict (or typing.Dict)
• None
• Pydantic Models
• Dataclasses
• typing.TypedDict
• NamedTuple

You can allow unions by just passing more parameters:

@app.get('/hello')
@app.query("name", str, None)
async def hello(name: str | None):
    if not name:
        return "hello world"

    return f"hello {name}"

You can pass type arguments to a dict, which are also validated by the server:

@app.get("/something")
@app.body("data", dict[str, int])  # typing.Dict on 3.8 and 3.9
async def something(data: dict[str, int]):
    # data will always be a dictionary of strings and integers
    return "..."

The key in a dictionary must always be str (i.e. dict[int, str] is not allowed), but the value can be any supported type (including other dictionaries!)

Objects

Here's an example of using an object type with dataclasses:

from view import new_app, query
from dataclasses import dataclass, field

app = new_app()

def now() -> str:
    ...  # Calculate current time

@dataclass
class Post:
    content: str
    created_at = field(default_factory=now)


@app.post("/create")
@app.query("data", Post)
async def create(data: Post):
    print(f"Created post {data.created_at}")
    return "Success", 201

You may also have recursive types, like so:

class MyOtherObject(NamedTuple):
    something: int

class MyObject(NamedTuple):
    something: str
    another_thing: MyOtherObject

Typed Dictionaries

You may use typing.TypedDict to type your dictionary inputs if you don't want to use a basic dict[..., ...] (or typing.Dict), like so:

from view import new_app
from typing import TypedDict

app = new_app()

class MyDict(TypedDict):
    a: str
    b: int

@app.get("/")
@app.query("data", MyDict)
async def index(data: MyDict):
    return data["a"]

app.run()

You may also use NotRequired to allow certain keys to get omitted:

class MyDict(TypedDict):
    a: str
    b: NotRequired[int]

View Body Protocol

If you would like to create your own object that gets validated by view.py, you may use the __view_body__ protocol.

A __view_body__ should contain a dictionary containing the keys and their corresponding types, like so:

from view import new_app

app = new_app()

class MyObject:
    __view_body__ = {"a": str, "b": int}

@app.get("/")
@app.query("data", MyObject)
async def index(data: MyObject):
    ...

app.run()

The above would ensure the body contains something like the following in JSON:

{
    "data": {
        "a": "...",
        "b": 0
    }
}

A default type can be annotated via view.BodyParam:

class MyObject:
    __view_body__ = {
        "hello": BodyParam(types=(str, int), default="world"),
        "world": BodyParam(types=str, default="hello"),
    }

Note that __view_body__ can also be a static function, like so:

class MyObject:
    @staticmethod
    def __view_body__():
        return {"a": str, "b": int}

Initialization

By default, an object supporting __view_body__ will have the proper keyword arguments passed to it's __init__.

If you would like to have special behavior in your __init__, you may instead add a static __view_construct__ function that returns an instance:

class MyObject:
    __view_body__ = {"a": str, "b": int}

    def __view_construct__(**kwargs):
        return MyObject()