Will Dart support the use of existing JavaScript libraries?

The answer is now Yes! Dart now ships a JS-interop library to use existing JavaScript code with your Dart app. Learn more here: https://www.dartlang.org/articles/js-dart-interop/

You will not be able to call javascript directly from dart code. The native directive is reserved for the core libraries of dartc (dart:core, dart:dom, dart:html, dart:json, etc), which itself compiles to javascript.

There is now a new simpler way https://pub.dartlang.org/packages/js (currently version 0.6.0-beta.6)

Make JS classes and functions available to Dart like:

@JS("JSON.stringify")external String stringify(obj);

@JS('google.maps')library maps;// Invokes the JavaScript getter `google.maps.map`.external Map get map;// `new Map` invokes JavaScript `new google.maps.Map(location)`@JS()class Map {  external Map(Location location);  external Location getLocation();}// `new Location(...)` invokes JavaScript `new google.maps.LatLng(...)`//// We recommend against using custom JavaScript names whenever// possible. It is easier for users if the JavaScript names and Dart names// are consistent.@JS("LatLng")class Location {  external Location(num lat, num lng);}

for more see the readme of the package