JSF Ajax Invoke Application is not executed?

Question

I have this simple facelets page:

<!DOCTYPE html>
<html xmlns:h="http://xmlns.jcp.org/jsf/html"
      xmlns:f="http://xmlns.jcp.org/jsf/core">
<h:head>
    <title>Index</title>
</h:head>
<h:body>
    <h:form>
        <h:inputText id="firstname" value="#{fooBar.firstname}">
            <f:ajax event="keyup" render="echo" execute="myCommandButton"/>
        </h:inputText>
        <h:commandButton value="Submit" action="#{fooBar.fooBarAction()}" id="myCommandButton"/>
    </h:form>
    <br/>
    <h:outputText id="echo" value="#{fooBar.firstname}"/>
</h:body>
</html>

and the Foobar bean is as follows:

@ManagedBean
@ApplicationScoped
public class FooBar {

    private String firstname;

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

    public String getFirstname() {
        return firstname;
    }

    public void fooBarAction() {
        System.out.println("Foo bar action being executed!!!");
    }
}

So my expectation is to see the text Foo bar action being executed whenever I type something in the inputText field, but it is not the case. What am I missing?

Edit: Why am I expecting this behavior? I am studying the book Core JavaServer Faces and in the book it is noted that:

JSF 2.0 splits the JSF life cycle into two parts: execute and render.

Execute consists of: Restore View -> Apply Request Values -> Process Validations -> Update Model Values -> Invoke Application

When JSF executes a component on the server, it:

-Converts and validates the component 's value (if the component is an input).

-Pushes valid input values to the model (if the component is wired to a bean property).

-Executes actions and action listeners (if the component is an action).

So here, myCommandButton should be executed, isn 't it? And execution of a component means its action to be executed?

Edit #2

This quotation is from JavaServer Faces Complete Reference

If listener is not specified, the only action that will be invoked during the Invoke Application phase will be the one that corresponds to an ActionSource component listed in the execute attribute.

So as far as I understand, in my example, I have a component that implements the ActionSource interface (myCommandButton), and the action attribute of this component should be executed. But it is not?

@BalusC I read that answer but I could not find where you explain why action attribute of the executed component is not called? — Koray Tugay
@BalusC There is no execute attribute in h:commandButton as well? I am not sure if that answer is relavent to my question. — Koray Tugay

BalusC BalusC · Accepted Answer · 2016-07-05T08:01:45

The execute attribute of <f:ajax> basically tells JSF which components to process through the JSF lifecycle during the postback. I.e. it basically tells JSF for which components it must execute the apply request values, process validations, update model values and invoke application phases. The apply request values phase will collect (decode) submitted HTML form (input and button) values. The validations phase will run conversion/validation on submitted values. The update model values phase will set submitted/converted/validated values in backing bean. The invoke application phase will execute the submitted action. Note that the key is that JSF will do this all based on submitted HTML form values.

In other words, the execute attribute is entirely server side. It is not client side as you seemed to expect. You seemed to expect that it tells the webbrowser to submit the specified component, as if you were clicking on it. This is not true. The button value is only processed through the JSF lifecycle when it was actually being pressed/clicked/submitted.

If the button is specified in execute attribute and JSF determines during processing the lifecycle that the button value is actually not submitted (i.e. it is entirely absent in HTTP request parameter map), then JSF won't queue the action event during apply request values phase at all. And therefore nothing will be invoked during invoke application phase.

When the <f:ajax> event is triggered, it's actually the enclosing component which is the action source. You should therefore hook the desired action listeners on it. You can use listener attribute of <f:ajax> for that.

<h:form>
    <h:inputText id="firstname" value="#{fooBar.firstname}">
        <f:ajax event="keyup" listener="#{fooBar.keyupListener}" render="echo" />
    </h:inputText>
    <h:commandButton value="Submit" action="#{fooBar.fooBarAction}" id="myCommandButton"/>
</h:form>

@ManagedBean
@RequestScoped
public class FooBar {

    private String firstname;

    public void keyupListener() {
        System.out.println("Keyup listener being executed");
    }

    public void fooBarAction() {
        System.out.println("Foo bar action being executed");
    }

    // ...
}

JSF Ajax Invoke Application is not executed?

2 Answers

See also: