How to set the value of a composite component from outside the composite component

Question

So, I have a composite component. Inside it, I have a regular text input, using one of the composite component's attributes for a value.

<h:inputTextarea id="#{cc.attrs.id}Text" value="#{cc.attrs.value}">
    <f:ajax event="blur" listener="#{someBean.onBlur}" />
</h:inputTextarea>

As you can see, I have an event inside the text box. This event opens a popup and populates it with the text on the composite control. It also saves a reference to the composite control that invoked it. Let me show you:

public void onBlur(AjaxBehaviorEvent event) {
    this.fieldReference = (UIInput) event.getSource();

    this.formula = this.fieldReference.getValueExpression("value")
            .getValue(FacesContext.getCurrentInstance().getELContext())
            .toString();

    this.displayPopup = true;
}

So far, so good. Now, the problem comes when I try to close the popup and then update the value on the composite component with the one entered on the popup. I try to do this:

public void accept(ActionEvent event) {
    this.fieldReference
            .getValueExpression("value")
            .setValue(FacesContext.getCurrentInstance().getELContext(), this.formula);
    this.displayPopup = false;
}

When I try that, I get:

javax.el.PropertyNotFoundException: //C:/myProject/Path/compositeComponentPage.xhtml at line 22 and column 183 value="#{cc.attrs.value}": Target Unreachable, identifier 'cc' resolved to null

Seems to me that the EL context on that request is different, and thus cannot resolve the variables in the composite component's expressions... but if I try to also store a reference to the ELContext object from the composite component's request (on the onBlur() method), then when I try to use it in accept(), I get:

javax.faces.event.AbortProcessingException: java.lang.IllegalStateException: Error the FacesContext is already released!

Using MyFaces 2.0.2 (the version that comes with WebSphere 8.5, I believe they modify it), and RichFaces 4.2.3.

Any ideas?

Small question: Have you tried (tried, not saying use in production) a newer myfaces version? 2.0.2 is 5 years old — Kukeltje, Jul 14 '15 at 23:50
You could also solve this client side with java script, is that an option? Or set the value to which the component is refering to (bean) and rerender the component. — W vd L, Jul 15 '15 at 09:36
@Kukeltje Unfortunately, that's not an option :( The library version is mandated by the container, and the container is mandated by the project's client. — José Ernesto Lara Rodríguez, Jul 15 '15 at 14:11
@WvdL Setting the value to which the component refers to is exactly what I was trying to do, unfortunately that cannot be determined statically (i.e. at compile time), because it's a component that will be used in multiple places to edit various properties of my entities. So I need to determine at runtime what I'm passing to the component on cc.attrs.value. — José Ernesto Lara Rodríguez, Jul 15 '15 at 14:14
Library is afaik, **not always** mandated by the container. Lots of posts on SO about updating JSF versions in containers. http://stackoverflow.com/questions/18141728/how-to-check-replace-the-myfaces-version-used-by-websphere-8-5. Maybe it is possible to upgrade this way. I'd certainly investigate it. — Kukeltje, Jul 15 '15 at 14:36
Ok, sorry, I wasn't specific enough. I meant, the container as-is is mandated by the client. We can't change anything. I know it sounds crazy, but there's a good reason... after all, I understand them. — José Ernesto Lara Rodríguez, Jul 15 '15 at 14:49

José Ernesto Lara Rodríguez · Accepted Answer · 2021-09-06T15:32:12.390

Well, I seem to have found a solution. Looking around, I found this small piece of knowledge in a totally unrelated article on BalusC's blog:

The backing component instance has basically a lifetime of exactly one HTTP request. This means that it's recreated on every single HTTP request, like as a request scoped managed bean.

So, saving a reference to the component is a very bad thing to do. Instead, I saved the client ID of the component and looked it up when closing the popup, then used setValue, which previously hadn't worked. Like this:

public void onBlur(AjaxBehaviorEvent event) {
    UIInput component = (UIInput) event.getSource();
    this.componentId = component.getClientId(FacesContext.getCurrentInstance());

    this.formula = component.getValueExpression("value")
        .getValue(FacesContext.getCurrentInstance().getELContext())
        .toString();

    this.displayPopup = true;
}

public void accept(ActionEvent event) {
    UIInput component = (UIInput) FacesUtil.findComponent(this.componentId);
    component.setValue(this.formula);

    this.displayPopup = false;
}

So... I guess thanks, BalusC, you saved the day again!! :)

How to set the value of a composite component from outside the composite component

1 Answers1