Struct js_sys::Proxy

#[repr(transparent)]
pub struct Proxy { /* fields omitted */ }

Methods

impl Proxy

pub fn new(target: &JsValue, handler: &Object) -> Proxy

The [Proxy] object is used to define custom behavior for fundamental operations (e.g. property lookup, assignment, enumeration, function invocation, etc).

MDN documentation

impl Proxy

pub fn revocable(target: &JsValue, handler: &Object) -> Object

The Proxy.revocable() method is used to create a revocable [Proxy] object.

MDN documentation

Methods from Deref<Target = JsValue>

pub const NULL: JsValue

pub const UNDEFINED: JsValue

pub const TRUE: JsValue

pub const FALSE: JsValue

pub fn as_f64(&self) -> Option<f64>

Returns the f64 value of this JS value if it's an instance of a number.

If this JS value is not an instance of a number then this returns None.

pub fn is_string(&self) -> bool

Tests whether this JS value is a JS string.

pub fn as_string(&self) -> Option<String>

If this JS value is a string value, this function copies the JS string value into wasm linear memory, encoded as UTF-8, and returns it as a Rust String.

To avoid the copying and re-encoding, consider the JsString::try_from() function from js-sys instead.

If this JS value is not an instance of a string or if it's not valid utf-8 then this returns None.

UTF-16 vs UTF-8

JavaScript strings in general are encoded as UTF-16, but Rust strings are encoded as UTF-8. This can cause the Rust string to look a bit different than the JS string sometimes. For more details see the documentation about the str type which contains a few caveats about the encodings.

pub fn as_bool(&self) -> Option<bool>

Returns the bool value of this JS value if it's an instance of a boolean.

If this JS value is not an instance of a boolean then this returns None.

pub fn is_null(&self) -> bool

Tests whether this JS value is null

pub fn is_undefined(&self) -> bool

Tests whether this JS value is undefined

pub fn is_symbol(&self) -> bool

Tests whether the type of this JS value is symbol

pub fn is_object(&self) -> bool

Tests whether typeof self == "object" && self !== null.

pub fn is_function(&self) -> bool

Tests whether the type of this JS value is function.

Trait Implementations

impl From<JsValue> for Proxy

fn from(obj: JsValue) -> Proxy

Performs the conversion.

impl From<Proxy> for JsValue

fn from(obj: Proxy) -> JsValue

Performs the conversion.

impl AsRef<JsValue> for Proxy

fn as_ref(&self) -> &JsValue

Performs the conversion.

impl Clone for Proxy

fn clone(&self) -> Proxy

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Proxy

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Deref for Proxy

type Target = JsValue

The resulting type after dereferencing.

fn deref(&self) -> &JsValue

Dereferences the value.

impl WasmDescribe for Proxy

fn describe()

impl IntoWasmAbi for Proxy

type Abi = <JsValue as IntoWasmAbi>::Abi

The wasm ABI type that this converts into when crossing the ABI boundary.

fn into_abi(self, extra: &mut dyn Stack) -> Self::Abi

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl<'a> IntoWasmAbi for &'a Proxy

type Abi = <&'a JsValue as IntoWasmAbi>::Abi

The wasm ABI type that this converts into when crossing the ABI boundary.

fn into_abi(self, extra: &mut dyn Stack) -> Self::Abi

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl FromWasmAbi for Proxy

type Abi = <JsValue as FromWasmAbi>::Abi

The wasm ABI type that this converts from when coming back out from the ABI boundary.

unsafe fn from_abi(js: Self::Abi, extra: &mut dyn Stack) -> Self

Recover a Self from Self::Abi.

impl RefFromWasmAbi for Proxy

type Abi = <JsValue as RefFromWasmAbi>::Abi

The wasm ABI type references to Self are recovered from.

type Anchor = ManuallyDrop<Proxy>

The type that holds the reference to Self for the duration of the invocation of the function that has an &Self parameter. This is required to ensure that the lifetimes don't persist beyond one function call, and so that they remain anonymous.

unsafe fn ref_from_abi(js: Self::Abi, extra: &mut dyn Stack) -> Self::Anchor

Recover a Self::Anchor from Self::Abi.

impl OptionIntoWasmAbi for Proxy

fn none() -> Self::Abi

Returns an ABI instance indicating "none", which JS will interpret as the None branch of this option.

impl<'a> OptionIntoWasmAbi for &'a Proxy

fn none() -> Self::Abi

Returns an ABI instance indicating "none", which JS will interpret as the None branch of this option.

impl OptionFromWasmAbi for Proxy

fn is_none(abi: &Self::Abi) -> bool

Tests whether the argument is a "none" instance. If so it will be deserialized as None, and otherwise it will be passed to FromWasmAbi.

impl JsCast for Proxy

fn instanceof(val: &JsValue) -> bool

Performs a dynamic instanceof check to see whether the JsValue provided is an instance of this type.

fn unchecked_from_js(val: JsValue) -> Self

Performs a zero-cost unchecked conversion from a JsValue into an instance of Self

fn unchecked_from_js_ref(val: &JsValue) -> &Self

Performs a zero-cost unchecked conversion from a &JsValue into an instance of &Self.

fn has_type<T>(&self) -> bool where
    T: JsCast, 

Test whether this JS value has a type T.

fn dyn_into<T>(self) -> Result<T, Self> where
    T: JsCast, 

Performs a dynamic cast (checked at runtime) of this value into the target type T.

fn dyn_ref<T>(&self) -> Option<&T> where
    T: JsCast, 

Performs a dynamic cast (checked at runtime) of this value into the target type T.

fn unchecked_into<T>(self) -> T where
    T: JsCast, 

Performs a zero-cost unchecked cast into the specified type.

fn unchecked_ref<T>(&self) -> &T where
    T: JsCast, 

Performs a zero-cost unchecked cast into a reference to the specified type.

fn is_instance_of<T>(&self) -> bool where
    T: JsCast, 

Test whether this JS value is an instance of the type T.

fn is_type_of(val: &JsValue) -> bool

Performs a dynamic check to see whether the JsValue provided is a value of this type.