[Laszlo-user] bug trying to extend baseformitem (kind of solved)

[Paulo Scardine]

P T Withington escreveu:
> Please file a bug at jira.openlaszlo.org.  I'm guessing the smallest 
> test case would be:
>
> <canvas>
>   <attribute name="z" value="" />
> </canvas>
>
> At the very least, the compiler should give you a more informative 
> message. But the question is, do you want the compiler to complain if 
> you have said you want the attribute to have a value, but failed to 
> give it a value (the double-quotes are not part of the value)?  Or do 
> you want the compiler to assume that you didn't mean to give it a 
> value after all?
>

Definitely the compiler should complain; I would be happy with an error, 
but the compiler could also issue a warning and assume value="" meaning 
value="null", value="''" or value="undfined".

Thanks,
--
Paulo
> Under the covers, the reason you are getting an error is what you wrote:
>
>   <attribute name="z" value="" />
>
> translates into the following Javascript:
>
>   var z = ;
>
> which is not valid.
>
> On 2008-08-12, at 11:57EDT, Paulo Scardine wrote:
>
>> This bug triggers only if I give a value of "", because value is an 
>> 'expression' attribute.  If  I use " ' ' " or "null" it works.
>>
>> I still think the compiler error message is awfully misleading.
>>
>> Thanks,
>> -- 
>> Paulo
>>
>> Paulo Scardine escreveu:
>>>
>>> Hi all,
>>>
>>> I would like to send some parameters to the backend while using a 
>>> form component. I tried to use dataset.setQueryParam, but soon I 
>>> learned that the submit.submit() will wipe any query parameter in 
>>> the dataset. The I tried to include a hidden form component in the 
>>> form, something like:
>>>
>>> ---------8<-----------------------------------------------------
>>> <canvas>
>>>
>>> <class name="hiddenfield" extends="baseformitem" />
>>> <class name="xtd_form" extends="form">
>>>   <hiddenfield name="key" value=""/>
>>> </class>
>>>
>>> <xtd_form name="a">
>>>   <statictext text="test" />
>>>   <edittext width="200" name="bla" />
>>> </xtd_form>
>>>
>>> </canvas>
>>> ---------8<-----------------------------------------------------
>>>
>>> This will fail with:
>>> ---------8<-----------------------------------------------------
>>> Compilation Errors
>>> Syntax error: the attribute value ended in mid-expression.
>>> Look for an unclosed '(', '{', or '['.
>>> ---------8<-----------------------------------------------------
>>>
>>> Apart from not showing any hint about the location of the offending 
>>> code, the message itself is very misleading. How nasty!
>>>
>>> How do you guys send hidden paramenters to the backend?
>>>
>>> Thaks in advance,
>>> -- 
>>> Paulo
>>>
>>>
>>>
>>>
>>
>