一个使使用wasm-bindgen更容易的crate。

该crate包含一个wasm_bindgen_struct宏，可以用来声明wasm-bindgen类型，并像使用普通Rust结构体一样实现getter/setter。它还可以用于实现类型的方法，包括内联映射来克服wasm-bindgen-futures的限制。

示例

// Or you can use this instead to avoid needing to import
// the macro throughout your crate
// #[macro_use]
// extern crate wasm_bindgen_struct;
use wasm_bindgen_struct::wasm_bindgen_struct;



#[wasm_bindgen_struct]
// `module` here means this type comes from the JS "my-module" module
// with the class name `aAnotherType`
#[opts(module = "my-module", js_name = "AnotherType")]
struct MyJsType {
  // field names are automatically converted to `camelCase`
  field_a: String,
  // ...but can be manually specified if needed
  #[opts(js_name = "field_b")]
  field_b: String,
}

#[wasm_bindgen_struct]
#[opts(module = "my-module")]
impl MyJsType {
  // Automatically gets the `static_method_of = MyJsType` applied,
  // as well as `catch` due to the `Result`
  fn apple() -> Result<String, JsValue>;

  // `async` functions in `wasm-bindgen` can only currently return
  // `()`, `JsValue`, or Result<_, JsValue>`, where `_` is one of
  // the two previously mentioned types. We use `MapValue<T, U>`
  // to tell the macro that the binding method should return `T`,
  // but we'll map the value to `U`
  async fn oranges(&self) -> MapValue<JsValue, String> {
    self
      .oranges_js()
      .await
      .unchecked_into::<js_sys::JsString>()
      .into()
  }
}

上面的代码展开为

// For getters/setters
#[wasm_bindgen(module = "my-module")]
extern "C" {
  #[wasm_bindgen(js_name = "AnotherType")]
  type MyJsType;

  #[wasm_bindgen(
    method,
    getter,
    js_class = "AnotherType",
    js_name = "fieldA"
  )]
  fn field_a(this: &MyJsType) -> String;

  #[wasm_bindgen(
    method,
    setter,
    js_class = "AnotherType",
    js_name = "fieldA"
  )]
  fn set_field_a(this: &MyJsType, value: String);

  #[wasm_bindgen(
    method,
    getter,
    js_class = "AnotherType",
    js_name = "field_b"
  )]
  fn field_b(this: &MyJsType) -> String;
  #[wasm_bindgen(
    method,
    setter,
    js_class = "AnotherType",
    js_name = "field_b"
  )]
  fn set_field_b(this: &MyJsType, value: String);
}

// And for methods
impl MyJsType {
  fn apple() -> Result<String, JsValue> {
    #[wasm_bindgen(module = "my-module")]
    extern "C" {
      #[wasm_bindgen(static_method_of = MyJsType, js_name = "apple")]
      #[wasm_bindgen(catch)]
      fn apple_js() -> Result<String, JsValue>;
    }
    Self::apple_js()
  }
  async fn oranges(&self) -> String {
    #[wasm_bindgen(module = "my-module")]
    extern "C" {
      #[wasm_bindgen(method, js_name = "oranges")]
      async fn oranges_js(this: &MyJsType) -> JsValue;
    }
    self
      .oranges_js()
      .await
      .unchecked_into::<js_sys::JsString>()
      .into()
  }
}

#[opts(...)]在结构体上

• dbg: bool

  在Type上显示宏的格式化输出作为警告

• on: Type

  允许使用结构体语法使用现有类型。

  示例

  
  
  
  #[wasm_bindgen]
  extern "C" {
    type JsType;
  }
  
  #[wasm_bindgen_struct]
  #[opts(on = JsType)]
  // Struct can be named anything, it doesn't matter
  struct JsType {
    field_1: bool,
  }
  

• extends: Type

• getter: bool

• setter: bool

• final_: bool

• js_name: Lit

• js_namespacejsnamespace: Vec: [Lit1, Lit2, Lit3, ...]

• module: Lit

• raw_module: Lit

• <unknown>

  未知属性，如文档注释，将被转发到type MyType声明，或者在on的情况下被忽略。