Monday, October 26, 2015

Re: JsInterop: Casting native javascript objects in gwt

I am using GWT 2.8.0-SNAPSHOT, but the new annotations does not work for me.

I tried using @JsType(namespace = "acme", name = "MyJavaScriptObject"), as described in the new version of the JsInterop document, but apparently the namespace and name attributes are not there in the jar file.
Same thing with the @JsExport and @JsNamespace, I currently have to use them or things stop working.

My gwt-user-2.8.0-SNAPSHOT.jar, which contains the annotations, is from today.


/Brian
 
Den mandag den 26. oktober 2015 kl. 11.43.32 UTC+1 skrev Thomas Broyer:
You may want to use GWT 2.8.0-SNAPSHOT and the new JsInterop annotations; as your usecase maybe is just not supported with the "old" annotations.

On Monday, October 26, 2015 at 11:10:28 AM UTC+1, Brian Pedersen wrote:
I have a dispatch method, exposed through JsInterop, which can take various kinds of payloads.

Once called from native javascript, I need to cast the payload, but this doesn't quite work as I would like it too.

Here is a simplified example.

GWT:
@JsExport
@JsType
@JsNamespace("foo")
public class Dispatcher {
public String dispatch(String action, Payload payload){
if("action1".equals(action))
return dispatchWithCast(payload);
return "Unknown action: " + action;
}
public String dispatchWithCast(Payload payload){
ConcretePayload w = (ConcretePayload) payload;
return w.foo;
}
}

@JsExport
@JsType
public class Payload {}

@JsExport
@JsType
public class ConcretePayload extends Payload {
public String foo;
public int bar;
}

Javascript:
var test = new foo.Dispatcher();
alert("Dispatch: " + test.dispatch("action1", {"foo": "a", "bar": 2})); // Uncaught java.lang.ClassCastException

Everything works just fine if I replace the Payload type in the Dispatcher class with ConcretePayload, and removes the cast.

I guess this this may be beyond the capabilities of the transpiler, I just need to figure out an alternative approach.

Any ideas?

(By the way, I am using the sso linker.)

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