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dart:js_interop›Extensions›JSFunctionUtilExtension

JSFunctionUtilExtension ​

extension JSFunctionUtilExtension on JSFunction

Utility extensions for JSFunction.

Methods ​

callAsFunction() extension ​

JSAny? callAsFunction([
  JSAny? thisArg,
  JSAny? arg1,
  JSAny? arg2,
  JSAny? arg3,
  JSAny? arg4,
])

Call this JSFunction using the JavaScript .call syntax and returns the result.

Takes at most 4 args for consistency with other APIs and relative brevity. If more are needed, you can declare your own external member with the same syntax.

Available on JSFunction, provided by the JSFunctionUtilExtension extension

Implementation
dart
// We rename this function since declaring a `call` member makes a class
// callable in Dart. This is convenient, but unlike Dart functions, JavaScript
// functions explicitly take a `this` argument (which users can provide `null`
// for in the case where the function doesn't need it), which may lead to
// confusion.
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/call
@JS('call')
external JSAny? callAsFunction([
  JSAny? thisArg,
  JSAny? arg1,
  JSAny? arg2,
  JSAny? arg3,
  JSAny? arg4,
]);