Pass values to/from [callback] function?

[lukeed]

I haven't been able to figure out how to pass value(s) to a Rust callback nor how to read an output value on the JS side from a Rust callback.

If you could provide a simple example for each of those that'd be very much appreciated!

[mishushakov]

The main example seems outdated, here's a working one:

use rusty_jsc::{JSContext, JSObject, JSValue};
use rusty_jsc_macros::callback;

#[callback]
fn foo(
    ctx: JSContext,
    function: JSObject,
    this: JSObject,
    args: &[JSValue],
) -> Result<JSValue, JSValue> {
    println!("Argument value: {}", args[0].to_string(&ctx).unwrap());
    Ok(JSValue::string(&ctx, "Returning a string from Rust!"))
}

fn main() {
    let mut context = JSContext::default();
    let callback = JSValue::callback(&context, Some(foo));
    let global = context.get_global_object();
    global.set_property(&context, "foo", callback).unwrap();

    match context.evaluate_script("foo('Hello from Rust')", 1) {
        Ok(value) => {
            println!("{}", value.to_string(&context).unwrap());
        }
        Err(e) => {
            println!("Uncaught: {}", e.to_string(&context).unwrap())
        }
    }
}