percy_router/
provided.rs

1use crate::router::Router;
2use std::any::TypeId;
3use std::ops::Deref;
4use std::rc::Rc;
5
6/// Data that was provided by the developer.
7///
8/// ```ignore
9/// struct State {
10///     count: u8
11/// }
12///
13/// #[route(path = "/")]
14/// fn route_provided_data(state: Provided<State>) -> VirtualNode {
15///     VirtualNode::Text(format!("Count: {}", state.count).into())
16/// }
17///
18/// fn main () {
19///     let mut router = Router::new(vec![]);
20///     router.provide(State {count: 50});
21/// }
22/// ```
23pub struct Provided<T> {
24    /// The application data to provide to a route.
25    pub data: Rc<T>,
26}
27
28impl<T> Deref for Provided<T> {
29    type Target = T;
30
31    fn deref(&self) -> &Self::Target {
32        &self.data
33    }
34}
35
36impl<T> Clone for Provided<T> {
37    fn clone(&self) -> Self {
38        Provided {
39            data: Rc::clone(&self.data),
40        }
41    }
42}
43
44impl Router {
45    /// Provide the application state data that different routes need.
46    pub fn provide<T: 'static>(&self, provided: T) {
47        let provided = Provided {
48            data: Rc::new(provided),
49        };
50
51        let type_id = TypeId::of::<Provided<T>>();
52
53        let provided = Box::new(provided);
54
55        self.provided.borrow_mut().insert(type_id, provided);
56    }
57}
58
59#[cfg(test)]
60mod tests {
61    use super::*;
62
63    struct State {
64        count: u8,
65    }
66
67    #[test]
68    fn provide() {
69        let router = Router::new(vec![]);
70        router.provide(State { count: 50 });
71
72        let state = router.provided.borrow();
73        let state = state
74            .get(&TypeId::of::<Provided<State>>())
75            .unwrap()
76            .downcast_ref::<Provided<State>>()
77            .expect("Downcast state");
78
79        assert_eq!(state.count, 50);
80    }
81}