« Return to Thread: Help with custom tag attribute

Re: Help with custom tag attribute

by FkJ :: Rate this Message:

Actually the problem is that f:attribute is not evaluating the the EL. If I pass the value literally it accepts, but if I pass #{maxlength} it is trying to set the string "#{maxlength}" as maxleght, so thats why the I get the ClassCastException.

<h:outputLabel value="#{label}" />
    <h:inputText
        label="#{label}"
        value="#{value}"
    >
        <c:if test="#{! empty id}">
            <f:attribute
                name="id"
                value="#{id}"
            />
        </c:if>
        <ui:insert />
    </h:inputText>

The id attribute is a better exemple of what I'm trying to do. When it's not set in the custom tag I'd like that it is not set in the h:inputText tag so that JSF generates the id. Otherwise always when I use the custom tag I'll have to set the id or write some crazy workaround to generate it so that I don't get a duplicated id exception.

Any ideias? Does f:attribute only accepts literals?

Thanks,
Felipe

2009/5/6 joseph j marini <josephjmarini@...>

Try mapping value to a backing bean #{foo.maxLength}
in your backing if max length is optional return null, else return
Integer object with value set. It will get converted automatically.

/Joe

--------------------------------------------------
From: "Zarar Siddiqi" <zarars@...>
Sent: Wednesday, May 06, 2009 11:26 AM
To: <users@...>
Subject: Re: Help with custom tag attribute

There's a difference between saying something is optional by passing
in a null, entirely another to pass in a string and expect it to be
ignored just because its not an integer.

What is the value of maxlength when you pass it in? Is it null or a string?

On Fri, Apr 24, 2009 at 1:16 PM, Felipe Jaekel <fkjaekel@...> wrote:

I have a custom tag that is composed by a <h:outputLabel /> + <h:inputText
/>. I need the maxlength attribute to be optional. The problem is that when
I use <f:attribute /> I get a class cast exception.

Tag:

<ui:composition
xmlns:h="http://java.sun.com/jsf/html"
xmlns:c="http://java.sun.com/jstl/core"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
>
<h:outputLabel value="#{label}" />
<h:inputText
label="#{label}"
value="#{value}"
>
<c:if test="#{! empty maxlength}">
<f:attribute
name="maxlength"
value="#{maxlength}"
/>
</c:if>
<ui:insert />
</h:inputText>
</ui:composition>

Exception:

java.lang.ClassCastException: java.lang.String cannot be cast to
java.lang.Integer

Any ideas?

Thanks,
Felipe

---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@...
For additional commands, e-mail: users-help@...

---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@...
For additional commands, e-mail: users-help@...

« Return to Thread: Help with custom tag attribute