Context

The Context is a beauty of an object unique to Lilya. The context is a parameter that can be used inside the function handlers and provides additional information that you might need for any particular reason.

Very similar approach to Request in terms of implementation but not the same. In fact, a context contains also the request and information about the handler itself.

Importing is as simple as:

from lilya.context import Context

The Context class

You can see the context as the request context of a given handler. This also means, when a function handler (view) is declared all the information passed to it is automatically accessible via context.handler parameter.

from lilya.context import Context
from lilya.responses import make_response


def home(context: Context):
    """
    Accessing the context object.
    """
    return make_response(content=None, status_code=204)

The context also provides access to the request object as well as the application settings and other functions.

This means, if you want to pass a request and context you actually only need the context directly as the request is already available inside but you can still pass both anyway.

Example

from lilya.apps import Lilya
from lilya.context import Context
from lilya.routing import Path


def read_context(context: Context, id: str):
    host = context.request.client.host

    context_data = context.get_context_data()
    context.add_to_context("name", "Lilya")

    context_data = context.get_context_data()
    context_data.update({
        "host": host, "user_id": id
    })
    return context_data


app = Lilya(
    routes=[
        Path("/users/{id}", read_request)
    ]
)

The context becomes especially valuable when you need to retrieve handler information that is unavailable after the handler's instantiation. For instance, it proves useful when accessing context.settings to retrieve application settings, offering a versatile approach to accessing them.

Attributes

Handler

The function handler that is responsible for the request.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    handler = context.handler

    return Response("Ok")

Request

The request being used for the scope of the handler.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    request = context.request

    return Response("Ok")

User

The user allocated in the request.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    user = context.user

    return Response("Ok")

User

The user allocated to the request.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    user = context.user

    return Response("Ok")

Settings

The settings being used by the Lilya application.

This can be the global settings or if a settings_module was provided, returns that same settings.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    settings = context.settings

    return Response("Ok")

Scope

The scope of the application handler.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    scope = context.scope

    return Response("Ok")

Application

The Lilya application.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    app = context.app

    return Response("Ok")

Methods

The context provides also different functions to manipulate the object.

get_context_data

The context of the application. This can be particularly useful when working with templates.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    context = context.get_context_data()

    return Response("Ok")

add_to_context

Adding values into the current context.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    context.add_to_context("call", "ok")

    return Response("Ok")

path_for

Retrives the path of a specific handler.

from lilya.context import Context
from lilya.responses import Response


def home(context: Context):
    url = context.path_for("/home")

    return Response(url)