HABTM association with Strong Parameters is not saving user in Rails 4

问题

User model:

has_and_belongs_to_many :events

Event model:

has_and_belongs_to_many :users

Users controller:

params.require(:user).permit(:role, {:event_ids => []})

Events controller:

params.require(:event).permit(:subject, :location, :date, :time, :all_day, :reminder, :notes, {:users_ids => []})

My form:

<%= simple_form_for(@event) do |f| %>
    <%= f.input :subject %>
    <%= f.input :location %>
    <%= f.input :date %>
    <%= f.input :time %>
    <%= f.association :users %>
    <%= f.input :all_day %>
    <%= f.input :reminder %>
    <%= f.input :notes %>

    <%= f.button :submit, :class =>"btn btn-default" %>
<% end %>

I want to be able to choose a user from a list and save that user to the database. But I am getting the following message in my console when I try to create a new Event:

Unpermitted parameters: user_ids

Do I have my setup incorrect? Am I not passing in the correct instance variables to the form?

回答1:

Ugh...details details!

How it was previously:

params.require(:event).permit(:subject, :location, :date, :time, :all_day, :reminder, :notes, {:users_ids => []})

How it should be:

params.require(:event).permit(:subject, :location, :date, :time, :all_day, :reminder, :notes, {:user_ids => []})

Notice that :users_ids should actually be :user_ids!

回答2:

Or you can simply use shorthand syntax like this.

params.require(:event).permit(:subject, :location, :date, :time, :all_day, :reminder, :notes, user_ids: [])

Notice: user_ids: [] instead of {:user_ids => []}

回答3:

Attribute from simple_form: user_ids

Symbol in #permit: users_ids

You've added an s, remove that and you should be good to go as far as I can tell.

回答4:

In my case I had a Rails 3 installation before. I upgraded to Rails 4. The select just passed a string, not an association. Thus the syntax proposed did not work. I simply had to allow user_ids. I.e.:

params.require(:event).permit(:subject, :location, :date, :time, :all_day, :reminder, :notes, :user_ids)

It seems Rails 4 changed the behavior.

来源：https://stackoverflow.com/questions/24820249/habtm-association-with-strong-parameters-is-not-saving-user-in-rails-4

标签

ruby-on-rails-4

strong-parameters

has-and-belongs-to-many