Need the equivalent to on_navigation from anvil_extras

yahiakala commented 2 days ago

Is your feature request related to a problem? Please describe. I want to migrate from anvil_extras and one of the last pieces is the on_navigation method in the main router form, documented here:

https://anvil-extras.readthedocs.io/en/latest/guides/modules/routing.html#on-navigation-example

Describe the solution you'd like I'm fine with any solution, including a method defined in a route class. Kind of like how we have a before_load method in the route class.

Describe alternatives you've considered I have put the code in the nav_click method in the template form, but this is not ideal as I want the on_navigation code to be executed any time a route is loaded. before_load doesn't really work since I need to access components in the form.

I am considering making a PR for this issue Yes

s-cork commented 2 days ago

I'd strongly recommend repacing your navigation links with the NavLink components from routing

This eliminates a bunch of code:

selected role is automatically applied for you
click navigates to the path as you expect
users can ctrl/cmd click to open in a new tab
hovering over the link shows the destination url

But to keep existing code as is it's possible to add on_navigation handling using the tools available in the router

here's a demo:

https://anvil.works/build#clone:YJO4ZDVBJRIY4BQZ=7CTS4MGWCF3MQYM4PTXQLFBC

from ._anvil_designer import MainTemplate
from routing import router

class Main(MainTemplate):
    def __init__(self, **properties):
        self.links = {"/": self.home_nav, "/about": self.about_nav}
        self.init_components(**properties)

    def on_navigate(self, **event_args):
        context = router.get_routing_context()
        for path, link in self.links.items():
            if path == context.path:
                link.role = "selected"
            else:
                link.role = None

    def home_nav_click(self, **event_args):
        router.navigate("/")

    def about_nav_click(self, **event_args):
        router.navigate("/about")

    def form_show(self, **event_args):
        router.add_event_handler("navigate", self.on_navigate)
        self.on_navigate()

    def form_hide(self, **event_args):
        router.remove_event_handler("navigate", self.on_navigate)

Looks like I haven't documented this yet so i'll add this to the docs and also add this in the migration guide for hash routing

yahiakala commented 1 day ago

Thanks, all good now. Switched to nav links

anvil-works / routing

Need the equivalent to on_navigation from anvil_extras #42