Multiple select issue with a HABTM relationship using Rails 4

Question

Although the code seems to be right, when I try to send the form, the values of the multiple select aren\'t being sent.

If I just remove the multiple option, everyth

Answer 1

Be sure what you properly allow received params for mass assignment.

You said that the one param works, so I assume what you have somewhere in your controller something like:

params.require(:transaction).permit(:name, :tag_ids)

So you need allow to receive an array:

params.require(:transaction).permit(:name, :tag_ids => [])

Answer 2

I solved my problem using

{:health_unit_ids => []}

Rails 4 no accepted without {}