toExternalReference property - ObjectToExternalDartReference extension - dart:js_interop library (original) (raw)

ExternalDartReference<T> gettoExternalReference

An opaque reference to this value of type T which can be passed to JavaScript.

When compiling to JavaScript, a Dart object is a JavaScript object, and therefore this directly returns the Dart object. When compiling to Wasm, an internal Wasm function is used to convert the Dart object to an opaque JavaScript value. If this value is null, returns null.

A value of type ExternalDartReference should be treated as completely opaque. It can only be passed around as-is or converted back usingExternalDartReferenceToObject.toDartObject.

When this getter is called multiple times on the same Dart object, the underlying references in the resulting ExternalDartReferences are guaranteed to be equal. Therefore, == will always return true between such ExternalDartReferences. However, like JS types, identical between such values may return different results depending on the compiler.

Implementation

external ExternalDartReference<T> get toExternalReference;