Strange in Tapestry binding

[duymap]

Hi all,

Does anyone see the similar binding as below:

Java code:
Student student;

Tml file:

<input value={student?.name} />

I don't know why they add "?" in data binding ?

Thanks,
Duy.

[Peter Skala]

the expression does not throw an exception, wenn getStudent() returns null.
best regards, Peter

> Hi all,
>
> Does anyone see the similar binding as below:
>
> Java code:
> Student student;
>
> Tml file:
>
> <input value={student?.name} />
>
> I don't know why they add "?" in data binding ?
>
> Thanks,
> Duy.
>

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[duymap]

Thanks so much Peter !

Duy.


On Wed, Aug 6, 2014 at 5:30 PM, <[hidden email]> wrote:

> the expression does not throw an exception, wenn getStudent() returns null.
> best regards, Peter
>
> > Hi all,
> >
> > Does anyone see the similar binding as below:
> >
> > Java code:
> > Student student;
> >
> > Tml file:
> >
> > <input value={student?.name} />
> >
> > I don't know why they add "?" in data binding ?
> >
> > Thanks,
> > Duy.
> >
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [hidden email]
> For additional commands, e-mail: [hidden email]
>
>

--
Chung Khánh Duy
Project Support Manager
Formos

[JumpStart]

This guide is handy:

        http://tapestry.apache.org/property-expressions.html

Geoff

On 6 Aug 2014, at 8:37 pm, Chung Khanh Duy <[hidden email]> wrote:

> Thanks so much Peter !
>
> Duy.
>
>
> On Wed, Aug 6, 2014 at 5:30 PM, <[hidden email]> wrote:
>
>> the expression does not throw an exception, wenn getStudent() returns null.
>> best regards, Peter
>>
>>> Hi all,
>>>
>>> Does anyone see the similar binding as below:
>>>
>>> Java code:
>>> Student student;
>>>
>>> Tml file:
>>>
>>> <input value={student?.name} />
>>>
>>> I don't know why they add "?" in data binding ?
>>>
>>> Thanks,
>>> Duy.
>>>
>>
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: [hidden email]
>> For additional commands, e-mail: [hidden email]
>>
>>
>
>
> --
> Chung Khánh Duy
> Project Support Manager
> Formos

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[duymap]

Thank you for your link, Geoff.

Duy.


On Thu, Aug 7, 2014 at 9:46 AM, Geoff Callender <
[hidden email]> wrote:

> This guide is handy:
>
>         http://tapestry.apache.org/property-expressions.html
>
> Geoff
>
> On 6 Aug 2014, at 8:37 pm, Chung Khanh Duy <[hidden email]>
> wrote:
>
> > Thanks so much Peter !
> >
> > Duy.
> >
> >
> > On Wed, Aug 6, 2014 at 5:30 PM, <[hidden email]> wrote:
> >
> >> the expression does not throw an exception, wenn getStudent() returns
> null.
> >> best regards, Peter
> >>
> >>> Hi all,
> >>>
> >>> Does anyone see the similar binding as below:
> >>>
> >>> Java code:
> >>> Student student;
> >>>
> >>> Tml file:
> >>>
> >>> <input value={student?.name} />
> >>>
> >>> I don't know why they add "?" in data binding ?
> >>>
> >>> Thanks,
> >>> Duy.
> >>>
> >>
> >>
> >>
> >> ---------------------------------------------------------------------
> >> To unsubscribe, e-mail: [hidden email]
> >> For additional commands, e-mail: [hidden email]
> >>
> >>
> >
> >
> > --
> > Chung Khánh Duy
> > Project Support Manager
> > Formos
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [hidden email]
> For additional commands, e-mail: [hidden email]
>
>

--
Chung Khánh Duy
Project Support Manager
Formos