dartify method - JSAnyUtilityExtension extension - dart:js_interop library (original) (raw)

Object? dartify()

Converts a JavaScript JSON-like value to the Dart equivalent if possible.

Effectively the inverse of NullableObjectUtilExtension.jsify, dartifytakes a JavaScript JSON-like value and recursively converts it to a Dart object, doing the following:

• If the value is a string, number, boolean, null, undefined,DataView or a typed array, does the equivalent toDart operation if it exists and returns the result.
• If the value is a simple JS object (the protoype is either null or JSObject), creates and returns a [Map]<Object?, Object?> whose keys are the recursively converted keys obtained from Object.keys and its values are the associated values of the keys in the JS object.
• If the value is a JS Array, each item in it is recursively converted and added to a new [List]<Object?>, which is then returned.
• Otherwise, the conversion is undefined.

If the value contains a cycle, the behavior is undefined.

Note

Prefer using the specific conversion member like toDart if you know the JavaScript type as this method may perform many type-checks. You should generally call this method with values that only contain JSON-like values as the conversion may be platform- and compiler-specific otherwise.

Implementation

// TODO(srujzs): We likely need stronger tests for this method to ensure
// consistency. We should also limit the accepted types in this API to avoid
// confusion. Once the conversion for unrelated types is consistent across all
// backends, we can update the documentation to say that the value is
// internalized instead of the conversion being undefined.
external Object? dartify();