Function leptos_core::Transition

pub fn Transition<F, E, G>(
    cx: Scope,
    props: TransitionProps<F, E, G>
) -> impl Fn() -> Childwhere
    F: IntoChild + Clone,
    E: IntoChild,
    G: Fn() -> E + 'static,

If any Resources are read in the children of this component, it will show the fallback while they are loading. Once all are resolved, it will render the children. Unlike Suspense, this will not fall back to the fallback state if there are further changes after the initial load.

Note that the children will be rendered initially (in order to capture the fact that those resources are read under the suspense), so you cannot assume that resources have Some value in children.

async fn fetch_cats(how_many: u32) -> Result<Vec<String>, ()> { Ok(vec![]) }

let (cat_count, set_cat_count) = create_signal::<u32>(cx, 1);
let (pending, set_pending) = create_signal(cx, false);

let cats = create_resource(cx, cat_count, |count| fetch_cats(count));

view! { cx,
  <div>
    <Transition
      fallback={"Loading...".to_string()}
      set_pending=set_pending
    >
      {move || {
          cats.read().map(|data| match data {
            Err(_) => view! { cx,  <pre>"Error"</pre> },
            Ok(cats) => view! { cx,
              <div>{
                cats.iter()
                  .map(|src| {
                    view! { cx,
                      <img src={src}/>
                    }
                  })
                  .collect::<Vec<_>>()
              }</div>
            },
          })
        }
      }
    </Transition>
  </div>
};