Expand description
The goal of this crate is to provide Rust bindings to the Web APIs and to allowa high degree of interoperability between Rust and JavaScript.
§Examples
You can directly embed JavaScript code into Rust:
letmessage ="Hello, 世界!";letresult =js! { alert( @{message} );return2+2*2;};println!("2 + 2 * 2 = {:?}", result );Closures are also supported:
letprint_hello = |name: String| {println!("Hello, {}!", name );};js! { var print_hello = @{print_hello}; print_hello("Bob"); print_hello.drop();// Necessary to clean up the closure on Rust's side.}You can also pass arbitrary structures thanks toserde:
#[derive(Serialize)]structPerson { name: String, age: i32}js_serializable!( Person );js! { var person = @{person}; console.log( person.name +" is "+ person.age +" years old.");};This crate also exposes a number of Web APIs, for example:
letbutton = document().query_selector("#hide-button").unwrap().unwrap();button.add_event_listener(move|_: ClickEvent| {foranchorindocument().query_selector_all("#main a") {js!( @{anchor}.style ="display: none;"; ); }});Exposing Rust functions to JavaScript is supported too:
#[js_export]fnhash( string: String ) -> String {letmuthasher = Sha1::new(); hasher.update( string.as_bytes() ); hasher.digest().to_string()}Then you can do this from Node.js:
var hasher = require( "hasher.js" ); // Where `hasher.js` is generated from Rust code.console.log( hasher.hash( "Hello world!" ) );Or you can take the same.js file and use it in a web browser:
<script src="hasher.js"></script><script> Rust.hasher.then( function( hasher ) { console.log( hasher.hash( "Hello world!" ) ); });</script>If you’re usingParcel you can also use ourexperimental Parcel plugin;first do this in your existing Parcel project:
$ npm install --save parcel-plugin-cargo-webAnd then simply:
import hasher from "./hasher/Cargo.toml";console.log( hasher.hash( "Hello world!" ) );Modules§
- serde
- A module with serde-related APIs.
- traits
- A module containing reexports of all of our interface traits.
- unstable
- A module containing stable counterparts to currentlyunstable Rust features.
- web
- A module with bindings to the Web APIs.
Macros§
- console
- Calls methods on the JavaScript
consoleobject. - js
- Embeds JavaScript code into your Rust program.
- js_
deserializable - A macro which makes it possible to convert an instance of a given typeimplementing Serde’s
Deserializeinto aValue usingTryInto. - js_
serializable - A macro which makes it possible to pass an instance of a given typeimplementing Serde’s
Serializeinto thejs! macro.
Structs§
- Array
- A type representing a JavaScript array.
- Discard
OnDrop - If you have a value which implements
Discard, you can useDiscardOnDrop::new(value)which will wrap the value.When the wrapper is dropped it will automatically callvalue.discard(). - Mut
- A wrapper for passing
FnMutcallbacks into thejs!macro. - Null
- A unit type representing JavaScript’s
null. - Number
- A type representing a JavaScript number.
- Object
- A type representing a JavaScript object.
- Once
- A wrapper for passing
FnOncecallbacks into thejs!macro. - Reference
- A type representing a reference to a JavaScript value.
- Symbol
- A type representing a JavaScript
Symbol. - Undefined
- A unit type representing JavaScript’s
undefined. - Unsafe
Typed Array - A wrapper type for exposing raw Rust slices as
TypedArraysat zero cost without copying.
Enums§
- Value
- A type representing a JavaScript value.
Traits§
- Instance
Of - A trait to check whenever a givenReference is of a certain type.
- JsSerialize
- A trait for types which can be serialized through the
js!macro. - Reference
Type - A trait for types which wrap a reference to a JavaScript object.
Functions§
- event_
loop - Runs Emscripten’s event loop.
- initialize
- Initializes the library.