Source code for ferrosoft.apps.ferrobase.middleware.appmeta

from asgiref.sync import iscoroutinefunction, markcoroutinefunction
from django.conf import settings

from ferrosoft.apps.ferrobase.apps import PLATFORM_APPS, AppMeta




class AppMetaMiddleware:
    """
    Set APP_META dict in request object.

    This dict includes information about the application: NAME and ICON_PATH.
    The app is determined by HTTP Host header, allowing different branding per app.
    """

    async_capable = True
    sync_capable = False

    # See https://www.rfc-editor.org/rfc/rfc3986.html#section-3.2.2
    #
    # "URI producers should use names that conform to the DNS syntax,
    # even when use of DNS is not immediately apparent, and should
    # limit these names to no more than 255 characters in length."
    HOST_NAME_MAX_LENGTH = 255

    SETTINGS_KEY = "FERROBASE_APP_HOSTS"

    def __init__(self, get_response):
        self.get_response = get_response
        if iscoroutinefunction(self.get_response):
            markcoroutinefunction(self)

    async def __call__(self, request):
        self._patch_request(request)
        return await self.get_response(request)

    def _patch_request(self, request):
        app_hosts = getattr(settings, self.SETTINGS_KEY, {})
        http_host = request.headers.get("host", "")
        http_host = http_host[: min(len(http_host), self.HOST_NAME_MAX_LENGTH)]
        meta = PLATFORM_APPS.get(app_hosts.get(http_host, "ferrobase"), None)
        if isinstance(meta, AppMeta):
            request.APP_META = meta