In a Drupal content type a need to get the output of a field partly unvisible. These are bank account details, the IBAN.
Normally the field shows 1234567. I need to get xxxx567. I need to show only the last 3 numbers/letters.
Also I need this output in field edit form.
On the display end you could change the output using a simple PHP function in the theme template by grabbing a substring of the field's last three digits and concatenating it with "xxxx" before printing.
You might also consider doing this at the formatter level by using the 'custom formatter' module perhaps?
https://drupal.org/project/custom_formatters
To do this on the edit screen is trickier. I suppose you could do a hook form alter to use PHP to change the field value, but I am afraid you will rewrite the field value when you save the node with the 'xxxx' instead of the real data.
I wonder if it would make sense to 1.) hide the actual field, 2.) create a dummy field that displays the text formatted as "xxxx567" to the user, and 3.) write some javascript that populates the hidden field with the visible field's value if it is changed. Presumably the form would still throw values if the hidden field did not meet formatting requirements.
