Rails conditional_select for nested attributes - ruby-on-rails

Question

I'm trying to setup the following: A User has many Groups through Memberships, a Group has many Events, and an Event has many Posts.
On my view to show a group with all of its events, I want a user to be able to write a new post by selecting the correct group from a drop down, writing a comment and submit. I'm currently using a collection_select to create the post, but the event_id is not getting passed to ActiveRecord, i.e. posts are created, but they do not have event_ids (or even comments):
class User < ActiveRecord::Base
has_many :memberships
has_many :groups, through: :memberships
has_many :posts
end
class Membership < ActiveRecord::Base
belongs_to :group
belongs_to :user
end
class Group < ActiveRecord::Base
has_many :memberships
has_many :events, dependent: :destroy
has_many :users, through: :memberships
end
class Event < ActiveRecord::Base
belongs_to :group
has_many :posts
end
class Post < ActiveRecord::Base
belongs_to :event
belongs_to :user
end
class GroupsController < ApplicationController
def show
#define new post
#new_post = Post.new
end
end
class PostsController < ApplicationController
def create
if #post = Post.create(params[post_params])
flash[:success] = "Post Created!"
else
redirect_to group_url
end
end
private
def post_params
params.require(:post).permit(:event_id, :comment)
end
end
<h1>New Post:</h1>
<%=form_for([#new_post]) do |f| %>
<%= render 'shared/error_messages', object: f.object %>
<div class = "field">
<%= f.label :event_name %>
<%= f.collection_select(:event_id, Event.all, :id, :title) %>
</div>
<div class = "field">
<%= f.text_area :comment, placeholder: "New Post..." %>
</div>
<%=f.submit "Submit", class: "btn btn-large btn-primary" %>
<%end%>
I have a feeling that because the routes are nested, group_id never is passed to the Posts controller, and so can never be set. But I'm sure there's a lot more wrong than that...

Answer 1

can you try to pass Post.create(post_params) instead of Post.create(params[post_params])
post_params is actually a full hash extracted from the params so you should not pass it to params again
If you want to add user_id
you should add to your view something like this
<%= f.hidden_field :user_id, value: current_user.id %>