Change mask pattern on the fly

Is it possible to change mask pattern on the fly? I would like something like that . If you start with 04 it changes it mask pattern.

[RicardoZambon]

Sorry update this closed topic, but adding more information in case anybody need this in the future, I was in need of a custom format accordingly to the field length.

The @uebbi example helped, but wasn’t complete, before setting the new Cleave() was needed destroy the previous instance.

Here is the complete code:

var activeFormat;

$('.cpfj').on('keyup', function() {
    if (activeFormat != null) {
        activeFormat.destroy();
        activeFormat = null;
    }
    
    if ($(this).val().length <= 14) {
        activeFormat = new Cleave('.cpfj', {
            numericOnly: true,
            blocks: [3, 3, 3, 3],
            delimiters : ['.', '.', '-']			
        });
    }
    else {
        activeFormat = new Cleave('.cpfj', {
            numericOnly: true,
            blocks: [2, 3, 3, 4, 2],
            delimiters : ['.', '.', '/', '-']
        });			
    }
});

And here is the Fiddle example, hope this help.

https://jsfiddle.net/Ricardozambon/kyx4c96n/

[RicardoZambon]

To fix the issue with the backspace, you must not reapply the mask format when the previous field length is equal to the current length.

I’ve updated the fiddle with this fix.

var oldValue = '';
if ($(this).data('old_val') != undefined) { oldValue = $(this).data('old_val'); }

var currentValue = this.value;
if (activeFormat != null) { currentValue = activeFormat.getRawValue(); }

if (oldValue.length != currentValue.length) {
    $(this).data('old_val', currentValue);
    ...
}