Display an StatusMessage from an Asynchronous method ?

[jeclic]

Hello,

I am having a problem trying to display a status message from an Asynchronous method.
The method is called from a button :

part of page.xhtml :

<h:messages globalOnly="true" styleClass="message" infoClass="messageInfo" errorClass="messageError" id="globalMessages"/>
<s:button  value="Message asynchronous" action="#{sourceFileManager.messageAsynchronous}" />

part of ISource.java :

@Local
public interface ISourceFileManager {
    @Asynchronous
    void messageAsynchronous(); 
}

part of Source.java :

@Name("source")
@Stateless
public class Source implements ISource {
    @In private StatusMessages statusMessages;

    public void messageAsynchronous() {
        this.statusMessages.add(Severity.INFO, "test message");
    }
}

It works great when the method is not Asynchronous...
It works also if a call the Asynchronous method from a synchronous method...but then I have to wait till the end of the treatment so I lose the advantages of @Asyncronous.

Any idea ?
Thank you

[kapitanpetko]

Asynchronous methods don't have access to the session/conversation, so this will not work. You need to do polling on the client side or use something like RichFaces' <ajax:push> to notify the client.

HTH

[jeclic]

Ok thank you for your answer I had understood that async methods don't have access to the session/conversation but I had no idea how to handle that, ajax:push seams to be the right way.

Just another question : is it a normal behavior that when I call my asynchronous method from a synchronous method, I have to wait till the end of the async treatment to do something else on the web page ?

Because I could display the message just before calling the async method...

Thank you

[kapitanpetko]

If you don't need the result form the asynchronous method, you don't have to wait for it to complete.

[jeclic]

Well I thought the same but I don't get it working with that code :

page.xhtml :

<s:button  value="Start treatment" action="#{source.callAsynchronous(otherClass.instance)}" />

ISource.java :

@Local
public interface ISourceFileManager {
    void callAsynchronous();

    @Asynchronous
    void asynchronousMethod();
}

Source.java :

@Name("source")
@Stateless
public class Source implements ISource {
    @In private StatusMessages statusMessages;

    public void callAsynchronous(Param param) {
        this.statusMessages.add(Severity.INFO, "Treatment is being started");

        asynchronousMethod(param);
    }

    public void asynchronousMethod(Param param) {
        // treatment
    }
}

Do you see something wrong ?
Thank you

[kapitanpetko]

For messages to be displayed, you need to submit the form. That doesn't happen with <s:button/>, use <h:commandButton/> instead.
Calling an asynchronous method from the same component generally doesn't work (it's not intercepted), so either have another component call it,
or use something like:

Source source = (Source)Component.getInstance("source");
source.asynchronousMethod();

[jeclic]

I created a new component for my asynchronous method and it works well :-)

Thank you for you help.