undefined method `each' for "27":String - ruby-on-rails

Question

I'm trying to get a number of users to be registered in a team , I updated my code so that a team can get registered, however the following error shows up :
undefined method `each' for "27":String
NoMethodError in TeamsController#create
My code is as follows:
class Team<ActiveRecord::Base
belongs_to :league
belongs_to :seed
has_many :speakers do
def user(level="1")
find_by(level: level).user
end
end
end
my user model looks like this :
class User < ActiveRecord::Base
belongs_to :team
end
user model:
class User<ActiveRecord::Base
has_many :speaking_engagements, class_name: "Speaker"
has_many :teams , through: :speaking_engagements
end
speaker model:
class Speaker < ActiveRecord::Base
belongs_to :team
belongs_to :user
end
Team Controller:
class TeamsController<ApplicationController
def new
#seed=Seed.find_by_id(params[:seed_id])
#league=current_admin.league
#team=current_admin.league.teams.build(:seed_id=>#seed,:approved=>false)
#usernames= #mca.connections.connected.each do |x| x.user end
end
def create
#league=current_admin.league
**#team = #league.teams.build(team_params)** #problem appears to be here
if #team.save
flash[:notice] = "Team Request Sent!."
redirect_to '/'
else
flash[:error] = "Unable to request team."
redirect_to :back
end
end
form looks like:
<div class="panel-body">
<div class="container">
<%= form_for #team do |f| %>
<%= f.hidden_field :seed_id, :value => #seed.id %>
<%= f.hidden_field :league_id, :value => #league.id %>
<div class="row">
<!-- <div class="col-md-8"> -->
<div class="form-group">
<%= f.collection_select :speakers, #usernames,:user_id,:fullname, multiple:true %>
</div>
<!-- </div> -->
</div>
<div class="actions">
<%= f.submit "Create" , class:"btn btn-primary" %>
</div>
<% end %>
</div>
</div>
Speaker migration:
class CreateSpeekers < ActiveRecord::Migration
def change
create_table :speakers do |t|
t.integer :team_id
t.integer :user_id
t.integer :level
t.timestamps null: false
end
end
end
I've been stuck with this error for quite sometime now, I would much appreciate any help!
Full trace:
activerecord (4.2.0) lib/active_record/associations/collection_association.rb:355:in `replace'
activerecord (4.2.0) lib/active_record/associations/collection_association.rb:47:in `writer'
activerecord (4.2.0) lib/active_record/associations/builder/association.rb:123:in `speekers='
activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `public_send'
activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `_assign_attribute'
activerecord (4.2.0) lib/active_record/attribute_assignment.rb:41:in `block in assign_attributes'
actionpack (4.2.0) lib/action_controller/metal/strong_parameters.rb:183:in `each_pair'
actionpack (4.2.0) lib/action_controller/metal/strong_parameters.rb:183:in `each_pair'
activerecord (4.2.0) lib/active_record/attribute_assignment.rb:35:in `assign_attributes'
activerecord (4.2.0) lib/active_record/core.rb:557:in `init_attributes'
activerecord (4.2.0) lib/active_record/core.rb:280:in `initialize'
activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new'
activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new'
activerecord (4.2.0) lib/active_record/reflection.rb:131:in `build_association'
activerecord (4.2.0) lib/active_record/associations/association.rb:247:in `build_record'
activerecord (4.2.0) lib/active_record/associations/collection_association.rb:136:in `build'
activerecord (4.2.0) lib/active_record/associations/collection_proxy.rb:254:in `build'
app/controllers/teams_controller.rb:13:in `create'
actionpack (4.2.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.2.0) lib/abstract_controller/base.rb:198:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.2.0) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
activesupport (4.2.0) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:92:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:92:in `_run_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_process_action_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.0) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (4.2.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `instrument'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
activerecord (4.2.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.2.0) lib/abstract_controller/base.rb:137:in `process'
actionview (4.2.0) lib/action_view/rendering.rb:30:in `process'
actionpack (4.2.0) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.2.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.2.0) lib/action_controller/metal.rb:236:in `block in action'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:73:in `call'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:42:in `serve'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:43:in `block in serve'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `each'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `serve'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:802:in `call'
warden (1.2.3) lib/warden/manager.rb:35:in `block in call'
warden (1.2.3) lib/warden/manager.rb:34:in `catch'
warden (1.2.3) lib/warden/manager.rb:34:in `call'
rack (1.6.4) lib/rack/etag.rb:24:in `call'
rack (1.6.4) lib/rack/conditionalget.rb:38:in `call'
rack (1.6.4) lib/rack/head.rb:13:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/flash.rb:260:in `call'
rack (1.6.4) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.6.4) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/cookies.rb:560:in `call'
activerecord (4.2.0) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.2.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:647:in `call'
activerecord (4.2.0) lib/active_record/migration.rb:378:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.0) lib/active_support/callbacks.rb:88:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:88:in `_run_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_call_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
web-console (2.2.1) lib/web_console/middleware.rb:39:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.0) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.0) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.4) lib/rack/runtime.rb:18:in `call'
activesupport (4.2.0) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/static.rb:113:in `call'
rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
railties (4.2.0) lib/rails/engine.rb:518:in `call'
railties (4.2.0) lib/rails/application.rb:164:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
rack (1.6.4) lib/rack/content_length.rb:15:in `call'
rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
/home/shyam/.rbenv/versions/2.2.1/lib/ruby/2.2.0/webrick/httpserver.rb:138:in `service'
/home/shyam/.rbenv/versions/2.2.1/lib/ruby/2.2.0/webrick/httpserver.rb:94:in `run'
/home/shyam/.rbenv/versions/2.2.1/lib/ruby/2.2.0/webrick/server.rb:294:in `block in start_thread'

Answer 1

The problem is that "27" (a user id) is being assigned as the speakers association for a team. This is wrong. speakers should be assigned instances of Speaker.
Unfortunately it gets tough at this point.
What you really need to do is use nested attributes to build the desired speaker records, where each speaker is assign one of the selected user ids. There are many ways to approach this in the UI. There are many great examples of using nested attributes, including this Railscasts episode

Answer 2

has_many gives you a lot of interesting methods, including collection_singular_ids and collection_singular_ids=. The gist of which means you should be able to leverage that getter & setter in your form like this
<%= f.collection_select :speaker_ids, #usernames, :user_id, :fullname, multiple: true %>

Answer 3

i found the answer to my question, thanks to following #WizardOfOgz comment,
so i did the following:
in my teams_controller.rb added the following parameters as permitted :
params.require(:team).permit(:user_id, :league_id,:seed_id, :approved, :speakers_attributes=>[:team_id,:user_id])
end
then,
in my team.rb added the follwing :
accepts_nested_attributes_for :speakers
further, added nested attributes in the form for team:
(in app/views/teams/_form.html.rb )
<h2>Speakers</h2>
<%= f.fields_for :speakers do |ff| %>
<div>
<%= ff.collection_select :user_id, #usernames,:user_id,:fullname%>
</div>
<% end %>
also since I wanted 3 speakers, I created the following function in helpers/form_helpers:
module FormHelper
def setup_team(team)
3.times{
team.speakers.build
}
team
end
end
that solved it for me,
thanks to #WizardOfOgz and #RichPeck
also this one really really helped:
http://www.sitepoint.com/complex-rails-forms-with-nested-attributes/