Written
Adding a new custom mask is very easy, just go to the 'Extra params' box in the text box settings and add this:
data-inputmask='mask' : '(999)999-9999'
Each 9 is a place-holder for a number [0-9], a can be used for alpha characters [a-z A-Z], and * for alphanumeric [0-9 a-z A-Z].
Here's another example from a forum query for a mask that would set a minimum and maximum length for a text input
data-inputmask='mask' : '*{4,12}', 'greedy': false, 'clearIncomplete': true
Full documentation can be found on GitHub here.
