util library

Utility functions for Dart <> JS interoperability.

Classes

Util

Properties

globalThis → Object
no setter
objectPrototype → Object?
Returns the Object prototype. Equivalent to Object.prototype.
no setter
util → Util
no setter

Functions

add<T>(Object? first, Object? second) → T
Perform JavaScript addition (+) on two values.
allowInterop<F extends Function>(F f) → F
Returns a wrapper around function f that can be called from JavaScript using package:js JavaScript interop.
allowInteropCaptureThis(Function f) → Function
Returns a wrapper around function f that can be called from JavaScript using package:js JavaScript interop, passing JavaScript this as the first argument.
and<T>(Object? first, Object? second) → T
Perform JavaScript logical and comparison (&&) of two expressions.
callbackToCompleter<T>(Completer<T> completer) → void Function(Object?, T)
Returns a function that can be passed to a Node.js-style asynchronous callback that will complete completer with that callback's error or success result.
callConstructor<T>(Object constr, List<Object?>? arguments) → T
callMethod<T>(Object o, Object method, List<Object?> args) → T
createDartExport<T extends Object>(T dartObject) → Object
Given a Dart object that is marked exportable, creates a JS object literal that forwards to that Dart class. Look at the @JSExport annotation to determine what constitutes "exportable" for a Dart class. The object literal will be a map of export names (which are either the written instance member names or their rename) to their respective Dart instance members.
createStaticInteropMock<T extends Object, U extends Object>(U dartMock, [Object? proto = null]) → T
Given a @staticInterop type T and an instance dartMock of a Dart class U that implements the external extension members of T, creates a forwarding mock.
dartify<T>(dynamic jsObject) → T
Returns Dart representation from JS Object.
delete<T>(Object o, Object property) → bool
Perform JavaScript delete operator (delete) on the given property of the given object.
divide<T>(Object? first, Object? second) → T
Perform JavaScript division (/) on two values.
equal<T>(Object? first, Object? second) → bool
Perform JavaScript equality comparison (==) on two values.
exponentiate<T>(Object? first, Object? second) → T
Perform JavaScript exponentiation (**) on two values.
futureToPromise<T>(Future<T> future) → Promise
Creates JS Promise which is resolved when future completes.
getProperty<T>(Object o, Object name) → T
greaterThan<T>(Object? first, Object? second) → bool
Perform JavaScript greater than comparison (>) of two values.
greaterThanOrEqual<T>(Object? first, Object? second) → bool
Perform JavaScript greater than or equal comparison (>=) of two values.
hasProperty(Object o, Object name) → bool
instanceof(Object? o, Object type) → bool
Check whether o is an instance of type.
instanceOfString(Object? element, String objectType) → bool
Like instanceof only takes a String for the object name instead of a constructor object.
invokeAsync0<T>(void function(void (Object?, T))) → Future<T>
Invokes a zero-argument Node.js-style asynchronous function and encapsulates the result in a Future.
invokeAsync1<S, T>(void function(S, void (Object?, T)), S arg1) → Future<T>
Invokes a single-argument Node.js-style asynchronous function and encapsulates the result in a Future.
isJavaScriptArray(dynamic value) → bool
Returns true if a given object is a JavaScript array.
isJavaScriptSimpleObject(dynamic value) → bool
Returns true if a given object is a simple JavaScript object.
isTruthy<T>(Object? o) → bool
Determines if the given object is truthy or falsy.
jsify(Object dartObject) → dynamic
Returns the JS representation from Dart Object.
lessThan<T>(Object? first, Object? second) → bool
Perform JavaScript less than comparison (<) of two values.
lessThanOrEqual<T>(Object? first, Object? second) → bool
Perform JavaScript less than or equal comparison (<=) of two values.
modulo<T>(Object? first, Object? second) → T
Perform JavaScript remainder (%) on two values.
multiply<T>(Object? first, Object? second) → T
Perform JavaScript multiplication (*) on two values.
newObject<T>() → T
not<T>(Object? o) → T
Perform JavaScript logical not (!) on the given object.
notEqual<T>(Object? first, Object? second) → bool
Perform JavaScript inequality comparison (!=) on two values.
objectGetPrototypeOf(Object? object) → Object?
Returns the prototype of a given object. Equivalent to Object.getPrototypeOf.
objectKeys(Object? object) → List<Object?>
Returns the keys for a given object. Equivalent to Object.keys(object).
or<T>(Object? first, Object? second) → T
Perform JavaScript logical or comparison (||) of two expressions.
promiseToFuture<T>(Promise promise) → Future<T>
Creates Dart Future which completes when promise is resolved or rejected.
setProperty<T>(Object o, Object name, T? value) → T
strictEqual<T>(Object? first, Object? second) → bool
Perform JavaScript strict equality comparison (===) on two values.
strictNotEqual<T>(Object? first, Object? second) → bool
Perform JavaScript strict inequality comparison (!==) on two values.
subtract<T>(Object? first, Object? second) → T
Perform JavaScript subtraction (-) on two values.
typeofEquals<T>(Object? o, String type) → bool
Perform JavaScript typeof operator on the given object and determine if the result is equal to the given type. Exposes the whole typeof equal expression to maximize browser optimization.
unsignedRightShift(Object? leftOperand, Object? rightOperand) → num
Perform JavaScript unsigned right shift operator (>>>) on the given left operand by the amount specified by the given right operand.

Exceptions / Errors

NullRejectionException
Exception for when the promise is rejected with a null or undefined value.