Unpermitted parameter using fields_for Rails - ruby-on-rails

Question

I got such message in console when trying to use fields_for in Rails:
Parameters: .... "task"=>{"task_name"=>"111", "tag"=>{"tag_text"=>"222"}}, "commit"=>"Save"}
Unpermitted parameter: tag
My models with has_many and belongs_to:
class Task < ActiveRecord::Base
has_many :tags
accepts_nested_attributes_for :tags
end
class Tag < ActiveRecord::Base
belongs_to :task
end
Form helper for new/edit page:
<%= form_for(#task) do |f| %>
<%= f.text_field :task_name %>
<%= f.fields_for([#task, #task.tags.build]) do |t| %>
<%= t.text_field :tag_text %>
<% end %>
<%= f.submit 'Save' %>
<% end %>
My Task Controller (I used scaffold to generate it, and its mostly default)
class TasksController < ApplicationController
before_action :set_task, only: [:show, :edit, :update, :destroy]
def index
#tasks = Task.all
end
def show
end
def new
#task = Task.new
#task.tags.build
end
def edit
#task.tags.build
end
def create
#task = Task.new(task_params)
respond_to do |format|
if #task.save
format.html { redirect_to #task, notice: 'Task was successfully created.' }
format.json { render :edit, status: :created, location: #task }
else
format.html { render :new }
format.json { render json: #task.errors, status: :unprocessable_entity }
end
end
end
def update
respond_to do |format|
if #task.update(task_params)
format.html { redirect_to edit_task_path, notice: 'Task was successfully updated.' }
format.json { render :edit, status: :ok, location: #task }
else
format.html { render :edit }
format.json { render json: #task.errors, status: :unprocessable_entity }
end
end
end
def destroy
#task.destroy
respond_to do |format|
format.html { redirect_to tasks_url, notice: 'Task was successfully destroyed.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_task
#task = Task.find(params[:id])
end
def task_params
params.require(:task).permit(:task_name, :task_sum, :status_id, :user_id, :target_release_id, tag_attributes: [:tag_text, :task_id])
end
end

Answer 1

I think the problem is in the way you use fields_for. Try to make this way:
<%= f.fields_for :tags do |t| %>
That way the param tags_attributes will be send and every thing should be fine.
EDIT
Also, if you are using Rails 5, you need to set the belongs_to as optional so the accepts_nested_attributes_for can work properly. So:
class Tag < ActiveRecord::Base
belongs_to :task, optional: true
end
And the parameters sanitization in your tasks_controller.rb you do not need tag_id under tags_attributes:
def task_params:
params.require(:task).permit(:task_name, tags_attributes: [:tag_text])
end
EDIT
I think I found your problem. Try to put tags_attributes instead of tag_attributes in your task_paramsmethod.