NullPointerException trying to render

Question

Hello,
I have a scenario I am not sure about. I have a command button tag on a JSF page. This tag is binded to a HtmlCommandButton instance field on a backing bean e.g.
<h:commandButton type="button" value="Find"
                                       binding="#{AddCaseForm.offenderFindButton}"
                                       immediate="false"/>When the page is being rendered for the first time (initial reqest) I would like this button to be rendered depending on a certain condition. So in the constructor of the managed bean I put:
if(condition){
          offenderFindButton.setRendered(false);
      }else{
          offenderFindButton.setRendered(true);
}The problem is I am getting a NullPointerException because the HtmlCommandButton variable offenderFindButton is null. When exactly does this variable get instantiated?
How am I able to conditionally render a HtmlCommandButton if not in the constructor of the bean?
Can someone please help?
Thanks.

Answer 1

Hi:
Try the rendered property in the tag itself.
Like this:
1) Define a boolean member in your backing bean and getter and setter for this boolean.
private boolean renderButton = false;
2) Include the rendered property in the button tag:
<h:commandButton id="button1" value="Button" action="next" rendered="#{backBean.renderButton}" ... />
Hope it helps you.
Felipe