Hi Joseph,

Koen will modify WWidget::doJavaScript() to guard against this.

In general, if you use jsRef(), it's a good idea to use
WWidget::doJavaScript() instead of WApplication::doJavaScript() to
assure that the jsRef() will be valid at the time that the JavaScript
is executed. The code executed by WWidget::doJavaScript() will execute
only after the widget is rendered, and will never be executed after
the widget is deleted.

Another solution for you is to write a JavaScript try-catch block
around your JS statement; as such the error will be silently ignored.

Best regards,
Wim.

2011/3/21 Joseph VanAndel <[email protected]>:
> Yes, it happens with Wt 3.1.8.  The problem is caused by my use of 
> WApplication::doJavaScript
>
> My application requires the user to login, and then creates various windows, 
> including
> a log window that I want to auto-scroll as I append messages.
>
> Koen Deforche advised me to do the following:
> =====================================================
> /*
>  * Little javascript trick to make sure we scroll along with new content
>  */
> WApplication::instance()->doJavaScript(messages_->jsRef() + ".scrollTop += "
>                   + messages_->jsRef() + ".scrollHeight;");
> =====================================================
>
>
> The problem appears to be that if I destroy this window, and create another 
> one when the user logs in again, the javascript added with 'doJavaScript()' 
> is trying to reference a non-existent window.
>
> Having called the doJavaScript() method, is there any way to disable the 
> javascript that was attached to the event with doJavaScript()?
>
>
> On Mar 21, 2011, at 9:38 AM, Koen Deforche wrote:
>
>> Hey Joseph,
>>
>> 2011/3/17 Joseph VanAndel <[email protected]>:
>>> I'm getting a similar problem:
>>> Wt internal error: TypeError: Result of 
>>> expression'$('#onft9go').get(0)'[undefined] is not an object, code: 
>>> undefined, description: undefined
>>
>> Also with an update to Wt 3.1.8 ?
>>
>> Any hints to what it could be related to ?
>>
>> Regards,
>> koen
>>
>> ------------------------------------------------------------------------------
>> Colocation vs. Managed Hosting
>> A question and answer guide to determining the best fit
>> for your organization - today and in the future.
>> http://p.sf.net/sfu/internap-sfd2d
>> _______________________________________________
>> witty-interest mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/witty-interest
>
>
> ------------------------------------------------------------------------------
> Enable your software for Intel(R) Active Management Technology to meet the
> growing manageability and security demands of your customers. Businesses
> are taking advantage of Intel(R) vPro (TM) technology - will your software
> be a part of the solution? Download the Intel(R) Manageability Checker
> today! http://p.sf.net/sfu/intel-dev2devmar
> _______________________________________________
> witty-interest mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/witty-interest
>

------------------------------------------------------------------------------
Enable your software for Intel(R) Active Management Technology to meet the
growing manageability and security demands of your customers. Businesses
are taking advantage of Intel(R) vPro (TM) technology - will your software 
be a part of the solution? Download the Intel(R) Manageability Checker 
today! http://p.sf.net/sfu/intel-dev2devmar
_______________________________________________
witty-interest mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/witty-interest

Reply via email to