Routing Context¶

A RoutingContext instance is passed to a form when it is instantiated. It provides information about the current route and the current navigation context.

from ._anvil_designer import IndexTemplate
from routing.router import RoutingContext


class Index(IndexTemplate):
    def __init__(self, routing_context: RoutingContext, **properties):
        self.routing_context = routing_context
        super().__init__(**properties)

Autocompletion

Adding the RoutingContext type definition will allow Anvil to show autocompletion for the routing_context property.

Properties¶

path: The path for the current route.
params: The parameters for the current route.
query: The query parameters for the current route.
hash: The hash for the current route.
deps: The dependencies dict returned by the cache_deps method.
nav_context: The navigation context for the current route. This is a dict and can be set by passing a nav_context argument to the navigate method. (Or equivalently by setting the nav_context attribute on a NavLink/Anchor component).
form_properties: The form properties for the current route. This is a dict and can be set by passing a form_properties argument to the navigate method. (Or equivalently by setting the form_properties attribute on the NavLink/Anchor component). Note the form_properties are passed as keyword arguments when instantiating a form. For more details see the Navigation section.
error: The error that occurred when loading the form or loading the data. This is particularly useful when displaying error messages in your error form.
data: The data for the current route. This is the value returned from the load_data method.
revalidating: True when routing is currently refreshing cached data in the background.

Events¶

The RoutingContext instance will emit events when the route changes.

data_loading: Emitted when the data is loading. This also fires from raise_init_events() if the current context already has cached data and is revalidating it in the background.
data_loaded: Emitted when data loads successfully. raise_init_events() also emits this event with the current data and error, so check routing_context.error when handling initial state.
data_error: Emitted when the data has an error.
query_changed: Emitted when the query parameters change.
hash_changed: Emitted when the hash changes.

Methods¶

invalidate(exact=False): Invalidates any cached data or forms for this routing context. If exact is True, then the path and deps must match exactly. By default this is False. If False, matching paths and their descendants are invalidated when their dependencies contain all the entries in this context's deps.
refetch(*, silent=None): Invalidates cached forms and data for this routing context with exact=True. If this is the current routing context, starts a new data load and returns its asynchronous result. Otherwise, returns without loading data. The silent value is passed through to load_data(...) as a loader argument. For server_fn routes, silent=True uses anvil.server.call_s(...), silent=False uses anvil.server.call(...), and silent=None uses the route default. Custom load_data(...) implementations can inspect silent and choose how to handle loading indicators or silent/background fetches.
raise_init_events(): Raises data_loaded, query_changed and hash_changed for the current state. Also raises data_error if an error exists and data_loading if data is revalidating. This method is useful during instantiation of the form. First set up your event handlers, then call raise_init_events().