dioxus/packages/core/examples/borrowed.rs

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//! Demonstrate that borrowed data is possible as a property type
//! Borrowing (rather than cloning) is very important for speed and ergonomics.
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//!
//! 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() {}
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use dioxus_core::prelude::*;
struct Props {
items: Vec<ListItem>,
}
#[derive(PartialEq)]
struct ListItem {
name: String,
age: u32,
}
fn app(ctx: Context, props: &Props) -> DomTree {
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let (_f, setter) = use_state(&ctx, || 0);
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ctx.render(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,
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ChildItem,
// create the props with nothing but the fc<T>
fc_to_builder(ChildItem)
.item(child)
.item_handler(setter)
.build(),
));
}
root.finish()
})
}
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type StateSetter<T> = dyn Fn(T);
// struct StateSetter<T>(dyn Fn(T));
// impl<T> PartialEq for StateSetter<T> {
// fn eq(&self, other: &Self) -> bool {
// self as *const _ == other as *const _
// }
// }
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// props should derive a partialeq implementation automatically, but implement ptr compare for & fields
#[derive(Props)]
struct ChildProps<'a> {
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// Pass down complex structs
item: &'a ListItem,
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// Even pass down handlers!
item_handler: &'a StateSetter<i32>,
}
impl PartialEq for ChildProps<'_> {
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fn eq(&self, _other: &Self) -> bool {
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// assume the dyn fn is never stable -
// wrap with use_callback if it's an issue for you
false
}
}
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fn ChildItem(_ctx: Context, _props: &ChildProps) -> DomTree {
todo!()
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// ctx.render(rsx! {
// div {
// item: child,
// handler: setter,
// abc: 123,
// onclick: props.item_handler,
// h1 { "abcd123" }
// h2 { "abcd123" }
// div {
// "abcd123"
// h2 { }
// p { }
// },
// }
// })
}
/*
rsx! {
ChildItem {
// props
item: child, handler: setter,
// children
div { class:"abcd", abc: 123 },
div { class:"abcd", abc: 123 },
// Auto-text coercion
"eyo matie {abc}",
// Anything that accepts Into<VChild>
{},
}
}
// dreaming of this syntax
#[derive(Properties)]
struct ChildProps<'a> {
username: &'a str,
item_handler: &'a dyn Fn(i32),
}
fn child_item(ctx: Context, props: &ChildProps) -> DomTree {
ctx.render(rsx! {
div {
class: "abc123",
abc: 123,
onclick: props.item_handler,
h1 { "Hello, {props.username}!" },
h2 { "Welcome the RSX syntax" },
div {
h3 { "This is a subheader" }
button {
onclick: props.handler,
"This is a button"
}
"This is child text"
},
}
})
}
// This is also nice
#[dioxus::component]
static CHILD: FC = |ctx, username: &str, handler: &dyn Fn(i32)| {
ctx.render(rsx! {
div {
class: "abc123",
abc: 123,
onclick: handler,
h1 { "Hello, {username}!" },
h2 { "Welcome the RSX syntax" },
div {
h3 { "This is a subheader" }
button {
onclick: props.handler,
"This is a button"
}
"This is child text"
},
}
})
}
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Menlo, Monaco, 'Courier New', monospace
struct Item {
name: String,
content: String,
}
#[dioxus::live_component]
static CHILD: FC = |ctx, username: &str, handler: &dyn Fn(i32)| {
// return lazy nodes or
let ssr = ctx.suspend(async {
let data = fetch("https://google.com")
.await?
.json::<Item>()
.await?;
rsx! {
div {
h1 { "Welcome: {data.name}" }
p { "Content: \n {data.content}" }
}
}
});
ctx.render(rsx! {
div {
class: "abc123",
abc: 123,
onclick: handler,
h1 { "Hello, {username}!" },
h2 { "Welcome the RSX syntax" },
div {
h3 { "This is a subheader" }
button {
onclick: props.handler,
"This is a button"
}
{ssr}
},
}
})
}
*/