checkboxes fieldtype: how to add a default selected option?

bump

I’d like to know if this is possible too

Me three. Or in my case, i’d like to have them all selected, or a “select all” mechanism.

I had to write a custom extension do to something similar in the control panel. I needed to pre-populate a date field and pre-select a relationship dropdown based on the logged-in user’s Member Group. My solution was to replicate the “jQuery for Control Panel” extension and modify it to include a javascript file with some jQuery that did these things. It felt kind of hack-ish, but it works!

Are these requests regarding the back-end control panel, or for a SAEF?