Pre-User: Can FlexiContent add data to a form submission?

You can already do this without creating a new custom field.

1. create a text field for the 8digit-number.
2. set its style attribute to hidden in
the template override from

form.php

or add a class within flexicontent.

3. set its value via php in

form.php

4. include the value into the email sent to user

EDIT:
Sorry, Point3 seems not to work in flexicontent. Its here far more complicated and not accessible as other cck's from Joomla. You have to do it via Javascript for ex. But this is dangerous because it could be altered by user. Serverside is needed even here to check uniqueness (and vulnerability if out-of-framework saving).

AT ggppdk: How can we access/differ the form value in form.php to be preset onload?
i see it to be called only prestructured like

Hello

exactly you must not rely on form posted value for critical data,

so you need to create the field value after the form is submitted

via FLEXIcontent field function:
onBeforeSaveField()

e.g. all important security data are checked after form is submitted in case the form was tampered,

categories access, create / edit privilege, etc, etc, also if you use the submit menu override, these are also checked after the form is submitted in case the user has tampered the form

Regards

Hello

if you duplicate the weblink field

then it will be easy to replace "weblink" with "myfieldtype"

(just take care to do case-sensitive replacements)

then zip it and install it via Joomla extensions Manager, and then publish it