[Typo3-dev] TS_CASE object does not support key value 0

[Martin Ficzel]

i stumbled over a problem writing a typoscript to change the 
tt_content.imagetext settings depending on the imageorient table

you can reproduce the problem with this ts-code

> page.20 = CASE
> page.20 {
>   key = 0
>   0 = TEXT
>   0.value = nothing
>   1 = TEXT
>   1.value = one
> } 

the key "0" is not rendered but many tablerows use this value as 
default. using the "default" key instead is not always a nice solution 
since it is sometimes intended to handle the value "0" different. in 
such a case i now have to write a default key and extra keys for every 
other possible value. thats not elegant and attracting errors.

i examined the sourcecode and found the following issues

at first i found out that a ts-line like "anyobject.0 = foobar"  is not 
parsed as ["anyobject"]["0"]["foobar"] because the value 0 is ignored by 
the ts-parser. i suggested a patch for that ( bug id:0001736 )

afterwards in the case object the value 0 is also not supported , insted 
of that the default key is rendered but thats not always what i intend. 
i also suggested a patch for that ( also bug id:0001736 )

question 1 : do you think these changes make sense ? or do they cause 
side effects i cant see right now?

question 2 : is it a good idea to check using "if(isset($value))" 
instead of "if($value)"

comparison examples to show the differences

> if (isset(""))   = 1 
> if (isset(NULL)) = 0
> if (isset("0"))  = 1
> if (isset("1"))  = 1
> 
> if ("")     = 0 
> if (NULL)   = 0 
> if ("0")    = 0 
> if ("1")    = 1

regards Martin