Hi, I'm not trying to do anything in the middle of the postback.
Suppose I have a request scope bean that has two fields: boolean displayField; String inputField; The inputField is displayed when displayField is true. displayField is initialized the first time with some request parameter is the URL that displays the form page. To be able to retain the value of displayField when the form is posted I put a hidden field in the form that is bound to displayField. When, on entering the form page displayField is true the field will be displayed. But when I fill in the field and post the form it is not set on the backing bean if displayField hasn't been set yet. It seems to me that what I'm trying to do is trivial and not uncommon. Is there another method of accomplishing this? How can I make sure the rendered state is saved without storing something in session scope. @Simon: I think your last point makes a lot of sense. If a component was rendered its value should be updated in the model. Why wouldn't that solve this problem? Thanks again, Freek -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: 05 augustus 2008 16:24 To: MyFaces Discussion Subject: Re: Setter not called for conditionally rendered fields [EMAIL PROTECTED] schrieb: > > Hi, > > I keep running into a problem where the setter of a field (say/ Field > 1/) in my backing bean (in request scope) that is rendered > conditionally is not called. > > I think what happens is that Trinidad evaluates the rendered condition > to determine if the setter should be called. My backing bean is sort > of stateless and needs to be filled with data from the form. > > Because the condition depends on another field (/Field 2/) in the > backing bean, the outcome of this evaluation will only be correct if > the setter of Field 2 was already called, which may or may not be the > case. So for some fields it will work but for other it will not. > > How can I get around this? > It is standard behaviour for JSF components to evaluate their "rendered" expression, and NOT write to the "value" property if rendered is false. This is nothing to do with Trinidad. If you have a view where the rendered property of a component depends upon the user-provided value of another field, then I don't think that is going to work. I wouldn't think it even depends on component order in the page; an EL expression uses only values that have already been pushed into the model, but a component uses the "rendered" state to determine whether to accept data from the posted form in an earlier phase, ie before any values are pushed to the model. See specification/javadoc for methods UIComponent.decode and UIComponent.processDecodes. I can't think of any solution for this. And I don't really understand why you are trying to do this either. You are trying to switch the "rendered" state of a component in the middle of the postback phase. Why? JSF really expects the rendered state during postback to match the rendered state that existed during the earlier render phase. As a side-point, does the JSF spec actually say that "rendered" EL expressions should be re-evaluated during postback? That's what MyFaces currently does, but it seems to me that the true/false state should really be part of the component's saved state and the restored value simply used during postback (and recalculated in render phase). That doesn't make any difference to the original question however. Regards, Simon ================================================ The information transmitted via this e-mail is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.
