CODEWITHSUNDEEP
dartdart-js-interop
Mason Bryant
Mason Bryant

Reputation: 1392

Expose Dart functions to javascript

I'm a bit of a newb to dart, and trying to get my feet wet by writing some library functions in it.

While I've had no problem calling javascript functions from dart, I'd love to be able to call dart functions from javascript, but so far, I'm not having much like.

For example, I'd love to be able to expose some basic functions from dart, for example like so:

main() {
  String foo() {
    return "bar!";
  }

  js.scoped(() {
    js.context.foo = foo;
  });
}

and then be able to call them from javascript, like so:

<script>
  window.onload = function() {
    alert("foo() = " + foo());
  }
</script>

Is something like this even possible?

Upvotes: 15

Views: 5493

Answers (3)

rkunboxed
rkunboxed

Reputation: 178

In Dart 2.3.0 I had to tweak the solution just a bit for allowInterop to play nice. 


    import 'dart:js' as js;
    main() {
      String foo() {
        return "bar!";
      }

      js.context['foo'] = js.allowInterop(foo);
    }

Upvotes: 3

G&#252;nter Z&#246;chbauer
G&#252;nter Z&#246;chbauer

Reputation: 657308

In Dart 1.20 I had to add allowInterop()

import 'dart:js' as js;
main() {
  String foo() {
    return "bar!";
  }

  js.context['foo'] = allowInterop(foo);
}

Upvotes: 4

Alexandre Ardhuin
Alexandre Ardhuin

Reputation: 76193

No problem ! see Calling Dart from JavaScript.

In your case :

import 'dart:js' as js;
main() {
  String foo() {
    return "bar!";
  }

  js.context['foo'] = foo;
}

Upvotes: 14

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