Ajax4Jsf

Lincoln — Mon, 25 Aug 2008 05:31:50 +0000

A4J:Form is missing several specified ajax functions

(View this issue on the JBoss tracker here. Keep reading, there is a fix… download fix)

The issue:

When using the a4j:form component, the data=”#{managedBean.property}” the properties defined in the data element list are supposed to be available after the a4j event in the data JavaScript variable; however, with the attribute is not correctly causing the JavaScript data variable to be populated.

The data variable is always undefined, even if the managed bean property is set to a valid value. This is exhibited by the alert box as the value is displayed, “(undefined)”.

Example:

—-

The workaround:

Taking a look at the source code revealed that the was not in fact including this behavior at all in the broadcast() method, which is where the data element processing occurs in the .

UIAjaxForm.broadcast()

    /* (non-Javadoc)
     * @see javax.faces.component.UIComponentBase#broadcast(javax.faces.event.FacesEvent)
     */
     public void broadcast(FacesEvent event)
               throws AbortProcessingException {
          // perform default
          super .broadcast(event);
          if (event instanceof  AjaxEvent) {
               // complete re-Render fields. AjaxEvent deliver before render response.
               setupReRender();
          }
     }

—-

In fact, however, if we modify the broadcast() method to behave like its relative, we can still achieve this functionality!

Updated: UIAjaxForm.broadcast()

    public void broadcast(final FacesEvent event) throws AbortProcessingException
    {
        super.broadcast(event);
        if (event instanceof AjaxEvent)
        {
            this.setupReRender();
            Object data = this.getData();
            AjaxContext ajaxContext = AjaxContext.getCurrentInstance(context);
            if (null != data)
            {
                ajaxContext.setResponseData(data);
            }
            String focus = this.getFocus();
            if (null != focus)
            {
                UIComponent focusComponent = RendererUtils.getInstance().findComponentFor(this, focus);
                if (null != focusComponent)
                {
                    focus = focusComponent.getClientId(context);
                }
                ajaxContext.getResponseDataMap().put(AjaxActionComponent.FOCUS_DATA_ID, focus);
            }
            ajaxContext.setOncomplete(this.getOncomplete());
        }
    }

—-

We’re set!

I don’t particularly like to repeat this code, so I may get around to refactoring everything and submitting it back to the Ajax4JSF project. For now, though, this blog will have to do.

I believe other functionality that was also broken included both the focus=”elementId” and the oncomplete=”javascriptCode”.

As always, please feel free to improve and comment on this. Enjoy!