Hello,
first time wasm bindgen user here. What I'm trying to do: create a rust object and then use it bi-directional in JavaScript. Now I can access and update the object properties directly (o.y), but I can't seem to change the nested struct with for example the following statement o.struct1.h = 3. I suspect I'm working on a copy, because Struct1 requires Copy and Clone. Why does it need Copy and Clone?
these lines work:
console.log(o.getH()+"|"+o.struct1.getH()); //answer: 10 | 10 ok!
o.setH(3);
console.log(o.getH()+"|"+o.struct1.getH()) //answer: 3 | 3 ok!
this is also "ok" (but why are these integers now?):
console.log(o.y); //answer: 0 ok!
o.y = 3.0;
console.log(o.y); //answer: 3 ok!
these don't:
o.struct1.h=3;
o.struct1.setH(3);
console.log(o.getH()+"|"+o.struct1.getH()) //answer: 10 | 10 (not OK!)
same:
o.getStruct1().h=3;
o.getStruct1().setH(3);
console.log(o.getH()+"|"+o.struct1.getH()) //answer: 10 | 10 (not OK!)
Cargo.toml
[package]
name = "t"
version = "0.0.1"
edition = "2018"
[lib]
crate-type = ["cdylib"]
[dependencies]
wasm-bindgen = "*"
[dependencies.web-sys]
version = "*"
[profile.release]
lto = true
index.html
<!DOCTYPE html>
<html>
<head>
<script type="module">
import {default as init, MyThing} from '/t/pkg/t.js';
async function run() {
await init('/t/pkg/t_bg.wasm');
let o = new MyThing();
/*
console.log(o.getH()+"|"+o.struct1.getH()); //answer: 10 | 10 ok!
o.setH(3);
console.log(o.getH()+"|"+o.struct1.getH()) //answer: 3 | 3 ok!
*/
/*console.log(o.y); //answer: 0 ok!
o.y = 3.0;
console.log(o.y); //answer: 3 ok!
*/
/*o.struct1.h=3;
o.struct1.setH(3);
console.log(o.getH()+"|"+o.struct1.getH()) //answer: 10 | 10 (not OK!)
*/
o.getStruct1().h=3;
o.getStruct1().setH(3);
console.log(o.getH()+"|"+o.struct1.getH()) //answer: 10 | 10 (not OK!)
}
run();
</script>
</head>
<body>
</body>
</html>
lib.rs
use wasm_bindgen::prelude::*;
#[wasm_bindgen(start)]
pub fn main() -> Result<(), JsValue> {
Ok(())
}
#[wasm_bindgen]
#[derive(Copy, Clone)] //why does it need Copy and Clone?
pub struct Struct1 {
pub h: u32,
}
#[wasm_bindgen]
impl Struct1 {
#[wasm_bindgen(method, js_name = "setH")]
pub fn set_h(&mut self, h: u32) {
self.h = h;
}
#[wasm_bindgen(method, js_name = "getH")]
pub fn get_h(&self) -> u32 {
self.h
}
}
#[wasm_bindgen]
pub struct MyThing {
pub struct1: Struct1,
pub y: f32,
}
#[wasm_bindgen]
impl MyThing {
#[wasm_bindgen(constructor)]
pub fn new() -> MyThing {
MyThing {
y: 0.0,
struct1: Struct1 {
h: 10,
},
}
}
#[wasm_bindgen(method, js_name = "getStruct1")]
pub fn get_struct1(&mut self) -> Struct1 { //ah, here it is copied? Can't return &mut Struct1
self.struct1
}
#[wasm_bindgen(method, js_name = "setH")]
pub fn set_h(&mut self, h: u32) {
self.struct1.h = h;
}
#[wasm_bindgen(method, js_name = "getH")]
pub fn get_h(&self) -> u32 {
self.struct1.h
}
}
