Notes posted by rogerdpack

multiple select has a hidden

It’s unclear if “select_tag” does this but the normal select method also generates a hidden variable if the “multiple” option is set, see http://apidock.com/rails/ActionView/Helpers/FormOptionsHelper/select

not submitted even if non-multiple in certain cases.

As a note, just for followers, even if a select is not “multiple” if it is “unselected” (ex: in javascript you can set its value like document.getElementById(‘select_id’).value = ‘a non option’; ). And if that form is submitted, the browser also seems to not send anything about it to the server. So it’s for non-multiples as well, just this case is rare since typically the select will default to its “first value” and then users can only change it another known value, so typically you won’t run into that. This isn’t related to rails but thought I’d mention it.

callbacks

As a note, AFAICT, this skips “validations” but does still run all callbacks still [like after_save, etc.] So if you’re looking for something that just updates see here: http://stackoverflow.com/a/7243777/32453

gives a parameter

As a note, you can use it like this:

after_save {|instance|

}

it will pass in the instance being saved.