Add formhandler field data to subject - typo3

Question

My goal is to have the Formhandler log UID inside the Admin emails subject.
Inside of my email template I'm using
###value_tx_formhandler_log_inserted_uid### to insert a unique id.
I need to get this value into my Admin emails subject. E.g.
"Order ID: ###value_tx_formhandler_log_inserted_uid###"
I've read various forum posts, each do something different and I ended up with this snippet:
plugin.Tx_Formhandler.settings.predef.form {
# TEMPLATE MARKERS
name = Form1
templateFile = typo3template/typo3/ext/formhandler/form1/default.html
markers {
name = TEXT
name.value = Form1
}
finishers {
1.config {
class = Tx_Formhandler_Finisher_Mail
subject = TEXT
subject.value = ###GP:tx_formhandler_log_inserted_uid###
}
}
[...]
which just yields "{$formhandler.admin.subject}" as the subject.
I also tried other variations like
###LLL:tx_formhandler_log_inserted_uid### or tx_formhandler_log_inserted_uid
The backend field "subject" is empty.
Pasting the HTML placeholder into the backend field didn't work either.
I can't get this to work.

Answer 1

In what way can you access the id you want to insert?
From the notation GP:tx_formhandler_log_inserted_uid I would assume a GET/POST value.
For using this value in typoscript you need to do it like this (or similar: dataWrap):
subject = TEXT
subject.data = GP:tx_formhandler_log_inserted_uid
subject.noTrimWrap = |Order ID: ||
The notation LLL:tx_formhandler_log_inserted_uid would be a language specific text (you would also insert by .data) but it would be a static text for each language.

Answer 2

After a lot of trial and error, I got it working.
First of all, I forgot to specify that I want to configure the admin mail.
Adding admin { fixed the problem of getting only {$formhandler.admin.subject}.
The UID value itself can be accessed with GP:formhandler|tx_formhandler_log_inserted_uid
I combined that with the noTrimWrap as suggested by #bernd-wilke-πφ
The final snippet looks like this:
finishers {
1 {
class = Tx_Formhandler_Finisher_Mail
config {
admin {
subject = TEXT
subject.data = GP:formhandler|tx_formhandler_log_inserted_uid
subject.noTrimWrap = |Order number: ||
}
}
}
}