Passing an array into hidden_field ROR

I'm trying to pass an array into a hidden_field. The following User has 3 roles [2,4,5] >> u = User.find_by_login("lesa") => #<User id: 5, login: "lesa", email: "lesa.beaupry@gmail.com", crypted_password: "0f2776e68f1054a2678ad69a3b28e35ad9f42078", salt: "f02ef9e00d16f1b9f82dfcc488fdf96bf5aab4a8", created_at: "2009-12-29 15:15:51", updated_at: "2010-01-06 06:27:16", remember_token: nil, remember_t

[plasma0713]

both the [][Ruby on Rails] to the end of the name attribute and multiple="multiple" to the input element, which is ideal. Rails uses this internally when it generates inputs for arrays, such as in fields_for.”

[hyone]

hidden_filed を配列として扱うにには、オプションに multiple: true を追加すればよい。ただし、デフォルト値を配列で渡すことはできないようだった。。。

[willnet]

f.hidden_field :role_ids, :multiple => true, :value => role.id とかできるの…