Rails 4 permit nested hash with dynamic keys

Question

Facing issues in permitting nested hash with dynamic keys in params. I have referred other similar questions on stack overflow but no luck so far. Any help is greatly appreciated. Below is the error raised.

ActionController::UnpermittedParameters found unpermitted parameters: volunteers_slots_attributes, sign_up_slots_attributes

{"event"=>{
"name"=>"ss", 
"volunteers_slots_attributes"=>{
"0"=>{"_destroy"=>"false", "needed_count"=>""},
"1"=>{"_destroy"=>"false", "needed_count"=>""},
... 
}, 
"sign_up_slots_attributes"=>{
"0"=>{"_destroy"=>"false", "title"=>"", "quantity"=>""}, 
"1"=>{"_destroy"=>"false", "title"=>"", "quantity"=>""}, 
"2"=>{"_destroy"=>"false", "title"=>"", "quantity"=>""},
 .... 
}, 
"supplies_note"=>""}}

Controller:

 def event_params
    params[:event].permit(:name,:supplies_note,
    :volunteers_slots_attributes,
    :sign_up_slots_attributes)
 end

Event Model:

  accepts_nested_attributes_for :sign_up_slots, allow_destroy: true, reject_if: :all_blank
  accepts_nested_attributes_for :volunteers_slots, allow_destroy: true, reject_if: :all_blank

Answer 1

You have to change your strong params like

params
  .require(:event)
  .permit(
    :name,
    :supplies_note,
    volunteers_slots_attributes: [
      :_destroy,
      :needed_count
    ],
    sign_up_slots_attributes: [
      :_destroy,
      :title,
      :quantity
    ]
  )