dioxus/packages/core/examples/borrowed.rs
2021-05-15 12:03:08 -04:00

77 lines
2.1 KiB
Rust

//! Demonstrate that borrowed data is possible as a property type
//! Borrowing (rather than cloning) is very important for speed and ergonomics.
//!
//! It's slightly more advanced than just cloning, but well worth the investment.
//!
//! If you use the FC macro, we handle the lifetimes automatically, making it easy to write efficient & performant components.
fn main() {}
use std::{borrow::Borrow, rc::Rc};
use dioxus_core::prelude::*;
struct Props {
items: Vec<ListItem>,
}
#[derive(PartialEq)]
struct ListItem {
name: String,
age: u32,
}
fn app<'a>(ctx: Context<'a>, props: &Props) -> DomTree {
let (val, set_val) = use_state(&ctx, || 0);
ctx.render(dioxus::prelude::LazyNodes::new(move |c| {
let mut root = builder::ElementBuilder::new(c, "div");
for child in &props.items {
// notice that the child directly borrows from our vec
// this makes lists very fast (simply views reusing lifetimes)
// <ChildItem item=child hanldler=setter />
root = root.child(builder::virtual_child(
c,
ChildItem,
// create the props with nothing but the fc<T>
fc_to_builder(ChildItem)
.item(child)
.item_handler(set_val.clone())
.build(),
None,
));
}
root.finish()
}))
}
// props should derive a partialeq implementation automatically, but implement ptr compare for & fields
#[derive(Props)]
struct ChildProps<'a> {
// Pass down complex structs
item: &'a ListItem,
// Even pass down handlers!
item_handler: Rc<dyn Fn(i32)>,
}
impl PartialEq for ChildProps<'_> {
fn eq(&self, _other: &Self) -> bool {
false
}
}
fn ChildItem<'a>(ctx: Context<'a>, props: &ChildProps) -> DomTree {
ctx.render(rsx! {
div {
onclick: move |evt| (props.item_handler)(10)
h1 { "abcd123" }
h2 { "abcd123" }
div {
"abcd123"
h2 { }
p { }
}
}
})
}