CODEWITHSUNDEEP
jsfprimefacesjavabeans
user3550464
user3550464

Reputation: 50

Refreshing a JSF/PrimeFaces interface from the backing Bean

My goal is to display a text on a web page, with JSF and/or PrimeFaces. The text is updated in real time by a process on the server side.

<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:p="http://primefaces.org/ui">

    <h:body>
        <f:view id="view">
            <f:event type="preRenderView" listener="#{MyBean.init}"/>
            <h:form>
                <p:outputLabel id="output" value="#{MyBean.text}"/>
            </h:form>
        </f:view>
    </h:body>
</html>

My backing bean maps the text to p:outputLabel. I also added to the bean a method foo() that modifies the text. This method is called by another process running in the background (it holds a pointer to the bean).

@ManagedBean(name="MyBean")
@SessionScoped
public class MyBean {
    private String text = "text";
    public void init() {
        MyOtherClass.getPointer(this);
    }
    public String getText() {
        return text;
    }
    public String foo(String s) {
        text = text + s;
        // ...and refresh ?
    }
}

What I cannot do so far, is to update/refresh the view automatically each time the text is updated. The best I could do is to let the user manually refresh the web page, or to use p:poll to refresh at regular intervals.

I have researched this, and I have found very similar threads; the answer is usually to use FacesContext.getCurrentInstance() (JSF) or RequestContext.getCurrentInstance() (PrimeFaces) to access the component and refresh it. I tried, but the context is not available in foo().

I guess it's a lifecycle issue. I have a very limited knowledge of JSF. Any help is appreciated.

Upvotes: 0

Views: 1558

Answers (1)

Kukeltje
Kukeltje

Reputation: 12337

You can't access a faces context from a bean when it is updated from a non jsf backend call. Use PrimeFaces push for this.

Upvotes: 0

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