4 releases
0.2.2 | Aug 28, 2023 |
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0.2.1 | Aug 26, 2023 |
0.2.0 | Aug 25, 2023 |
0.1.0 | Aug 25, 2023 |
#1015 in WebAssembly
7KB
65 lines
Let's pretend that life-before-main exists for Rust targeting WebAssembly.
Installation
Add a dependency on wasm-init
. This crate intentionally provides a no-op implementation for non-wasm platforms, so cfg
handling isn't necessary and we don't pull in unused extra deps.
[dependencies]
wasm-init = "0.2"
User Code
Add as many calls to wasm_init!
as required on the Rust side, e.g. for decentralised plugin registration or collecting data from all types that use a particular derive macro.
wasm_init::wasm_init! {
// literally any code you want to run at startup goes here
}
Initialisation
To ensure your wasm_init!
calls are executed on startup, you have three options. Note that all of these options are idempotent - multiple invocations are perfectly safe (if unnecessary), even in a threaded context.
Auto-init feature
If you'd like to skip manually initialising wasm-init
, you can enable the auto-init
feature as part of the dependency:
[dependencies]
wasm-init = { version = "0.2", features = [ "auto-init" ] }
But please bear in mind that this will prevent you from using a wasm bindgen start function elsewhere in your project.
From Rust
Call the wasm_init::wasm_init
function inside your Rust entrypoint.
From JavaScript/TypeScript
Call the wasm_init
export from your built module.
<script type="module">
import init, { wasm_init } from "./pkg/my_wasm_crate.js";
init().then(() => {
wasm_init();
// now do things as normal!
});
</script>
Why?
inventory et al are cool, but can't yet be used when targeting wasm32-unknown-unknown
or similar.
Dependencies
~0–315KB