Struct JsMetadataValue 

pub struct JsMetadataValue { /* private fields */ }

JavaScript-friendly metadata value representation.

This type bridges Rust’s MetadataValue enum to JavaScript objects. Use the static factory methods (fromString, fromInteger, etc.) to create values from JavaScript.

Example (JavaScript)

const strValue = JsMetadataValue.fromString('hello');
const intValue = JsMetadataValue.fromInteger(42);
const floatValue = JsMetadataValue.fromFloat(3.14);
const boolValue = JsMetadataValue.fromBoolean(true);
const arrValue = JsMetadataValue.fromStringArray(['a', 'b', 'c']);

console.log(strValue.getType()); // 'string'
console.log(intValue.toJS());    // 42

Implementations

impl JsMetadataValue

pub fn from_string(value: String) -> Self

Creates a string metadata value.

@param value - The string value @returns A new JsMetadataValue containing a string

pub fn from_integer(value: f64) -> Result<Self, JsError>

Creates an integer metadata value.

JavaScript numbers are always f64, so this method validates the input to ensure it’s a valid integer within JavaScript’s safe integer range.

@param value - The integer value (must be within ±(2^53 - 1)) @returns A new JsMetadataValue containing an integer @throws {Error} If value is outside safe integer range or has fractional part

Errors

Returns an error if:

• Value exceeds JavaScript’s safe integer range (±9007199254740991)
• Value has a fractional part (e.g., 3.14)
• Value is NaN or Infinity

pub fn from_float(value: f64) -> Self

Creates a float metadata value.

@param value - The float value (must not be NaN or Infinity) @returns A new JsMetadataValue containing a float

pub fn from_boolean(value: bool) -> Self

Creates a boolean metadata value.

@param value - The boolean value @returns A new JsMetadataValue containing a boolean

pub fn from_string_array(value: Array) -> Result<Self, JsError>

Creates a string array metadata value.

@param value - An array of strings @returns A new JsMetadataValue containing a string array

Errors

Returns an error if any array element is not a string.

pub fn get_type(&self) -> String

Returns the type of this value.

@returns One of: ‘string’, ‘integer’, ‘float’, ‘boolean’, ‘string_array’

pub fn is_string(&self) -> bool

Checks if this value is a string.

pub fn is_integer(&self) -> bool

Checks if this value is an integer.

pub fn is_float(&self) -> bool

Checks if this value is a float.

pub fn is_boolean(&self) -> bool

Checks if this value is a boolean.

pub fn is_string_array(&self) -> bool

Checks if this value is a string array.

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

Gets the value as a string.

@returns The string value, or undefined if not a string

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

Gets the value as an integer.

Note: Returns as f64 for JavaScript compatibility. Safe for integers up to ±2^53.

@returns The integer value as a number, or undefined if not an integer

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

Gets the value as a float.

@returns The float value, or undefined if not a float

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

Gets the value as a boolean.

@returns The boolean value, or undefined if not a boolean

pub fn as_string_array(&self) -> JsValue

Gets the value as a string array.

@returns The string array, or undefined if not a string array

pub fn to_js(&self) -> JsValue

Converts to a JavaScript-native value.

Returns:

• string for String values
• number for Integer and Float values
• boolean for Boolean values
• string[] for StringArray values

@returns The JavaScript-native value

Trait Implementations

impl From<JsMetadataValue> for JsValue

fn from(value: JsMetadataValue) -> Self

Converts to this type from the input type.

impl FromWasmAbi for JsMetadataValue

type Abi = u32

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

unsafe fn from_abi(js: u32) -> Self

Recover a Self from Self::Abi.

impl IntoWasmAbi for JsMetadataValue

type Abi = u32

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

fn into_abi(self) -> u32

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

impl LongRefFromWasmAbi for JsMetadataValue

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRef<JsMetadataValue>

Same as RefFromWasmAbi::Anchor

unsafe fn long_ref_from_abi(js: Self::Abi) -> Self::Anchor

Same as RefFromWasmAbi::ref_from_abi

impl OptionFromWasmAbi for JsMetadataValue

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 OptionIntoWasmAbi for JsMetadataValue

fn none() -> Self::Abi

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

impl RefFromWasmAbi for JsMetadataValue

type Abi = u32

The Wasm ABI type references to Self are recovered from.

type Anchor = RcRef<JsMetadataValue>

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) -> Self::Anchor

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

impl RefMutFromWasmAbi for JsMetadataValue

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRefMut<JsMetadataValue>

Same as RefFromWasmAbi::Anchor

unsafe fn ref_mut_from_abi(js: Self::Abi) -> Self::Anchor

Same as RefFromWasmAbi::ref_from_abi

impl TryFromJsValue for JsMetadataValue

fn try_from_js_value(value: JsValue) -> Result<Self, JsValue>

Performs the conversion.

fn try_from_js_value_ref(value: &JsValue) -> Option<Self>

Performs the conversion.

impl VectorFromWasmAbi for JsMetadataValue

type Abi = <Box<[JsValue]> as FromWasmAbi>::Abi

unsafe fn vector_from_abi(js: Self::Abi) -> Box<[JsMetadataValue]>

impl VectorIntoWasmAbi for JsMetadataValue

type Abi = <Box<[JsValue]> as IntoWasmAbi>::Abi

fn vector_into_abi(vector: Box<[JsMetadataValue]>) -> Self::Abi

impl WasmDescribe for JsMetadataValue

fn describe()

impl WasmDescribeVector for JsMetadataValue

fn describe_vector()

impl SupportsConstructor for JsMetadataValue

impl SupportsInstanceProperty for JsMetadataValue

impl SupportsStaticProperty for JsMetadataValue