An html select element looks like this:
<select name="cars">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="fiat">Fiat</option>
<option value="audi">Audi</option>
</select>
You have:
<h:selectOneMenu value="#{...}">
<f:selectItems value="#{anotherDataBean.selectItems}"/>
where the getSelectItems() method returns a list of SelectItem objects
whose string is the text you want to display, and the value is a
ComplexProp object, right?
So the renderer for the f:selectItems writes out one <option> tag for
each item in the list. The body text for the <option> tag is taken from
the SelectItem.label property. The SelectItem.value is a ComplexProp
object, and so the converter.getAsString method is called to generate
the string to write out as the "value" attribute. Obviously this occurs
once for each item in the list.
When the form is posted back, the browser will include in the posted
form data the *string value* of whatever option was selected by the
user. JSF calls the converter once, to map this string back to a
ComplexProp object, then (in update-model phase) stores the resulting
object using the "value" EL-expression of the h:selectOneMenu component.
So on render, getAsString is called N times, and on postback getAsObject
is called once.
Regards, Simon
Anton Gavazuk schrieb:
> Hi dushyant,
>
> thanks for response -
>
> which value I should return in getAsString method? - actual Key
> element or Value element? - because the selectOneItem is populated by
> SelectItem's elements.
>
> and why in debug I see that getAsString method is being called for N
> times (over all elements in binded array)?
>
> 2008/11/7 dushyant agarwal <[EMAIL PROTECTED]>:
>
>> In case of selection, the getAsObject would convert the selected value as
>> specified and send it to BB. In getAsString() method you again have to
>> specify some code to change the BB value into one of the values in the
>> selectItem list, bound to the selectOneMenu component.
>>
>>
>>
>> --- On Fri, 7/11/08, Anton Gavazuk <[EMAIL PROTECTED]> wrote:
>>
>>
>>> From: Anton Gavazuk <[EMAIL PROTECTED]>
>>> Subject: Re: confused about selectOneItem and converter and data binding
>>> To: "MyFaces Discussion" <[email protected]>
>>> Date: Friday, 7 November, 2008, 3:41 PM
>>> Guys,
>>> does anyone have any idea?
>>>
>>> 2008/11/6 Anton Gavazuk <[EMAIL PROTECTED]>:
>>>
>>>> Hi all,
>>>>
>>>> have a problem
>>>>
>>>> I have the JSF Bean dataBean with property complexprop
>>>>
>>> - the type of
>>>
>>>> field is ComplexType
>>>> I want to set an certain property to the bean via
>>>>
>>> selectItems, which
>>>
>>>> is being collected from the
>>>>
>>> anotherDataBean.selectItems - it returns
>>>
>>>> array of SelectItems.
>>>>
>>>> so it looks like
>>>>
>>>> <!--page-->
>>>> <h:selectOneMenu id="in_property"
>>>>
>>> value="#{dataBean.complexprop}">
>>>
>>>> <f:selectItems
>>>>
>>> value="#{anotherDataBean.selectItems}"/>
>>>
>>>> <f:converter
>>>>
>>> converterId="geoConverter"/>
>>>
>>>> </h:selectOneMenu>
>>>>
>>>> Of course it wouldnt not work because JSF would try
>>>>
>>> convert the String
>>>
>>>> value from UI to internal dataBean.complexprop type
>>>>
>>> and vice versa so
>>>
>>>> I added the converter
>>>> But I cannot understand how to work properly with it -
>>>>
>>> during the call
>>>
>>>> the method is being called for count =
>>>>
>>> selectItems.size()
>>>
>>>> Converter.getAsString(FacesContext facesContext,
>>>>
>>> UIComponent
>>>
>>>> uiComponent, Object o)
>>>>
>>>> What could be wrong?
>>>>
>>>> How to link together all such things?
>>>>
>>>>
>> Add more friends to your messenger and enjoy! Go to
>> http://messenger.yahoo.com/invite/
>>
>>
>
>
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