Allows the use of Dart classes and objects in javascript. Generates a special proxy classes.

Create javascript API for Dart become easier.


  • Class inheritance ( with @JsProxy )
  • Named constructors
  • Method
  • Optional positional parameters
  • Optional named parameters
  • Input parameter transform
  • Result mutation
  • Future (via result mutator)
  • Field
  • Getter/Setter

Not support:

  • Factory
  • Operator

Try It Now

Add the js_mimicry package to your pubspec.yaml file:

  js_mimicry: ">=0.2.0 <0.3.0"

Building and Deploying

To build a deployable version of your app, add the js_mimicry transformers to your pubspec.yaml file:

- js_mimicry


##Dart code

    class Test1{
      method1(p1,[p2]){/* code */}
      method2(p1,p2){/* code */}
    class Test2 extends Test1{
      int method2(p1,p2){/* new logic */}
      String method3(Test1 obj){/* code */}
      Future<int> method4(){/* code */}
      Test1 method5({namedP1, namedP2}){/* code */}
      String method6(int value){/* code */}

##Add annotation for class

    class Test1{  // ... cut ...

    class Test2 extends Test1{ // ... cut ...

##Add annotation for transform input parameter

    String method6(@JsTransform(ANY_TO_INT) int value){/* code */}

    static int ANY_TO_INT(Object v){
        if (v is String){
         return int.parse(v);
        return v as int;

##Add annotation for mutation result Future

    @JsMutator(insertParams:const ["resultCb","errorCb"],result:Test2.futureToCallbacks)
    Future<int> method4(){/* code */}
    static futureToCallbacks(Future result,js.JsFunction resultCb,[js.JsFunction errorCb]){
        if (errorCb!=null){
            result = result.catchError((err)=>errorCb.apply([err]));
        return result;

##Add annotation for mutation result

    Test1 method5(){/* code */}

    static ANY_TO_STRING(v)=>v.toString();

Import to javascript

    import 'dart:js' as js;
    import 'package:js_mimicry/annotation.dart';
      // Create instance Test1
      js.context["dartInstanceTest1"] = JsProxyFactory.toJs(new Test1());

Uses in javascript

    // Create Test2 instance, call method5 with named parameters
    new Test2().method5({namedP1:"123"});
    // call Test1.method1 with optional parameters

JsProxyFactory methods

###JsObject toJs(DartClass obj) Create proxy object for Test2 object. ###DartClass toDart(Type dartType, JsObject obj) Convert javascript proxy to real Dart object.