Unfortunately, a special sentinel value, instead of null isn't always
possible, since that may mean something else to a database.
- Mark
Roger Kitain wrote:
> Hello Mark -
>
> The spec says nothing about f:selectItem with null values.
> So, I do not think it is a bug in Moharra.
> However, for that use case, you could assign some number "0" - so you
> would have something like:
>
> <h:selectOneMenu value="#{bean.count}"
> valueChangeListener="#{bean.valueChangeListener}">
> <f:selectItem itemValue="1"/>
> <f:selectItem itemValue="2"/>
> <f:selectItem itemValue="3"/>
> <f:selectItem itemValue="4"/>
> <f:selectItem itemValue="5"/>
> <f:selectItem itemValue="0" itemLabel="Not specified"/>
> </h:selectOneMenu>
>
> If you still feel the spec could be clarified in this area, you can
> always file a spec issue in our issue tracker:
>
> https://javaserverfaces-spec-public.dev.java.net/
>
> Ryan Lubke wrote:
>
>>
>>
>> -------- Original Message --------
>> Subject: h:selectOneMenu selection and f:selectItem with null
>> itemValue
>> Date: Wed, 06 Feb 2008 15:03:13 -0700
>> From: Mark Collette <mark.collette_at_icesoft.com>
>> Reply-To: dev_at_javaserverfaces.dev.java.net
>> To: dev_at_javaserverfaces.dev.java.net
>>
>>
>>
>> A user filed a bug report with ICEfaces about the behaviour of our
>> ice:selectOneMenu component, and when I went to investigate it versus
>> stock JSF behaviour, I found that the unexpected behaviour was
>> actually with stock JSF 1.2. So, I'm hoping that I can get some
>> guidance here.
>>
>> Basically, if you want to use h:selectOneMenu to select from a list
>> of Long values, but also want to accomodate selecting null, there's a
>> problem. You can not make an f:selectItem with itemValue="#{null}"
>> because it will then use the itemLabel as the itemValue, so you'll be
>> trying to match h:selectOneMenu's value value to "Not specified"
>> instead of null. So then if you use itemValue="" it has inconsistent
>> behaviour. If you select it, then the bean will actually get null, in
>> both the property setter and the ValueChangeEvent, as desired. But
>> when it renders, it will not make the "Not specified" option be
>> selected. Nothing will be selected. Well, the browser will select by
>> default the first thing in the menu, which will be "1" in this case.
>>
>> My questions are, what is the desired behaviour, selecting "Not
>> specified", or nothing at all? Is this a bug in Mojarra, or is this
>> what the spec desires?
>>
>> Here's the example code:
>>
>> <html xmlns="http://www.w3.org/1999/xhtml"
>> xmlns:f="http://java.sun.com/jsf/core"
>> xmlns:h="http://java.sun.com/jsf/html">
>> <body>
>> <h:form>
>> <h:selectOneMenu value="#{bean.count}"
>> valueChangeListener="#{bean.valueChangeListener}">
>> <f:selectItem itemValue="1"/>
>> <f:selectItem itemValue="2"/>
>> <f:selectItem itemValue="3"/>
>> <f:selectItem itemValue="4"/>
>> <f:selectItem itemValue="5"/>
>> <f:selectItem itemValue="" itemLabel="Not specified"/>
>> </h:selectOneMenu>
>> <h:commandButton value="Submit"/>
>> </h:form>
>> </body>
>> </html>
>>
>> public class Bean {
>> private Long count = null;
>> public Long getCount() { return count; }
>> public void setCount(Long c) { count = c; }
>>
>> public void valueChangeListener(ValueChangeEvent event) {
>> System.out.println("valueChangeListener() newValue: " +
>> event.getNewValue());
>> }
>> }
>>
>>
>> Mark Collette
>> http://mark-icefaces-reflections.blogspot.com/
>>
>>
>>
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>>
>
>
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