Output additional Text in Powermail if specific Checkbox is checked - typo3

Question

so here's my problem: I tried to output an additional text once a specific checkbox is checked in powermail.
The select field contains multiple options and all are selectable of course, but when i.e. field 1 is checked the sender should have the standard text in the mail plus "Lorem ipsum", but when the field isn't checked there should be no additional output at all.
I could find a solution for altering texts depending on a selection for single selects / dropdowns and it works like a charm, but for a reason the multi-select doesn't work at all. I can't figure out why so maybe someone can help.
TS:
lib.serverex = CASE
lib.serverex {
key.data = GP:tx_powermail_pi1|field|produktang|1
key.intval = 1
1 = TEXT
1.value = Lorem Ipsum
#Default
default = TEXT
default.value =
}
The email in powermail looks like this:
Some standard text...
{f:cObject(typoscriptObjectPath:'lib.serverex', data:'{produktang}')}
The checkbox configuration inside the form (id: produktang):
first product | 1
second product | 2
third product | 3
fourth product | 4
fifth product | 5
Either it appends it no matter what the input is/checked boxes are or it doesn't send the additional text at all. I'm probably missing something here.
Thanks in advance!

Answer 1

The result of field {produktang} is an array (of course because it's a checkbox). So you have to find out if there is any key with value "2" (e.g. if you're searching for product 2) of in your case tx_powermail_pi1|field|produktang|1 == 2

Answer 2

I solved it now with kind of a trick because I couldn't make it work in a different way.
What I did:
I moved the specific product where the email alters to the first position in the multiselect element. So it's Index will be 0.
The next thing is to check if the element in position 0 of the array equals the desired product, in my case it's "firstProduct". Since it's in the first position it'll always be "firstProduct" if "firstProduct" is checked and the additional text will be "printed". I set the default text to an empty string so it'll stay blank in every other case.
Here's the code:
lib.serverex = CASE
lib.serverex {
key.data = GP:tx_powermail_pi1|field|produkt|0
firstProduct = TEXT
firstProduct.value = Lorem Ipsum
#Default
default = TEXT
default.value =
}
The configuration of the Checkbox inside powermail:
firstProduct
secondProduct
thirdProduct
fourthProduct
fifthProduct
And the code which is inside of the email itself:
{f:cObject(typoscriptObjectPath:'lib.serverex', data:'{produkt}')}
It probably works in another way as well, but I couldn't solve it another way. Hope this helps if someone encounters the same issues I had.