Routing

Routes may carry a stable name, metadata, a redirect, or an asynchronous data
loader.

Names and URLs

router.RegisterRoute(router.Route{
    Path: "/teams/:team",
    Children: []router.Route{{
        Path:      "users/:user",
        Name:      "team-user",
        Component: NewUserPage,
        Meta:      map[string]any{"section": "users"},
    }},
})

path := router.MustURL("team-user", map[string]string{
    "team": "core",
    "user": "ada",
}, url.Values{"tab": {"activity"}})

URL returns an error for an unknown route name or a missing path parameter.
Values are path escaped and query values use url.Values.Encode.

Redirect routes do not need a component:

router.RegisterRoute(router.Route{
    Path:     "/people/:id",
    Redirect: "/users/:id",
})

Data loaders

A loader completes before the new component is created and the previous page
is unmounted:

router.RegisterRoute(router.Route{
    Path:      "/users/:id",
    Component: NewUserPage,
    Loader: func(ctx context.Context, load router.LoadContext) (any, error) {
        return api.User(ctx, load.Params["id"])
    },
})

The component may receive the result by implementing:

func (page *UserPage) SetRouteData(data any) {
    page.user = data.(User)
}

Starting another navigation cancels the current loader. A failed or cancelled
loader leaves the mounted page in place. router.NavigateContext waits for
the result and returns its error, which is useful in tests and controlled
workflows.

The following signals expose transition state:

router.Status() // idle, loading, ready, error
router.Error()
router.Data()
router.Meta()
router.ActivePath()

Browser history navigation restores saved scroll positions. New and replaced
entries start at the top. Set Meta["preserveScroll"] to true for a route
that owns its scroll behavior, or call router.SetScrollRestoration(false) to
disable router management.

Built-in component wrappers

• core.NewPortal(selector, child) mounts a child below another DOM target.
  
• core.NewKeepAlive(child) detaches and caches a child’s DOM on route exit.
  Call Dispose when the cache should be released permanently.
  
• core.NewTransition(child, config) applies CSS enter and leave classes.
  Leave content is moved outside the router outlet until the configured
  duration ends.
  

A KeepAlive instance should be registered directly as the route component
so the router treats it as a singleton:

router.Page("/editor", core.NewKeepAlive(NewEditor()))