Unpermitted parameter: user_id error in rails - ruby-on-rails

Question

am using devise for authentication in a rails app everything is working fine, but i have a post model and after signing up when i try to create a new post it shows up an error:
1 error prohibited this post from being saved:
User must exist
I looked into the terminal and got this:
Unpermitted parameter: user_id
(0.0ms) begin transaction
(0.0ms) rollback transaction
i tried adding a user controller
users_controller.rb
class UsersController < ApplicationController
before_action :authenticate_user!
before_action :set_user
before_action :check_ownership, only: [:edit, :update]
respond_to :html, :js
# GET /users
# GET /users.json
def index
#users = User.all
end
# GET /users/1
# GET /users/1.json
def show
end
# GET /users/new
def new
#user = User.new
end
# GET /users/1/edit
def edit
end
# POST /users
# POST /users.json
def create
#user = User.new(user_params)
respond_to do |format|
if #user.save
format.html { redirect_to #user, notice: 'User was successfully created.' }
format.json { render action: 'show', status: :created, location: #user }
else
format.html { render action: 'new' }
format.json { render json: #user.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /users/1
# PATCH/PUT /users/1.json
def update
respond_to do |format|
if #user.update(user_params)
format.html { redirect_to #user, notice: 'User was successfully updated.' }
format.json { head :no_content }
else
format.html { render action: 'edit' }
format.json { render json: #user.errors, status: :unprocessable_entity }
end
end
end
# DELETE /users/1
# DELETE /users/1.json
def destroy
#user.destroy
respond_to do |format|
format.html { redirect_to users_url }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_user
#user = User.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def user_params
params.require(:user).permit(:name, :email)
end
end
my posts_controler.rb
class PostsController < ApplicationController
before_action :authenticate_user!, :except => [:show, :index]
before_action :set_post, only: [:show, :edit, :update, :destroy]
# GET /posts
# GET /posts.json
def index
#posts = Post.all
end
# GET /posts/1
# GET /posts/1.json
def show
end
# GET /posts/new
def new
#post = Post.new
end
# GET /posts/1/edit
def edit
end
# POST /posts
# POST /posts.json
def create
#post = Post.new(post_params)
respond_to do |format|
if #post.save
format.html { redirect_to #post, notice: 'Post was successfully created.' }
format.json { render :show, status: :created, location: #post }
else
format.html { render :new }
format.json { render json: #post.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /posts/1
# PATCH/PUT /posts/1.json
def update
respond_to do |format|
if #post.update(post_params)
format.html { redirect_to #post, notice: 'Post was successfully updated.' }
format.json { render :show, status: :ok, location: #post }
else
format.html { render :edit }
format.json { render json: #post.errors, status: :unprocessable_entity }
end
end
end
# DELETE /posts/1
# DELETE /posts/1.json
def destroy
#post.destroy
respond_to do |format|
format.html { redirect_to posts_url, notice: 'Post was successfully destroyed.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_post
#post = Post.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def post_params
params.require(:post).permit(:tittle, :body)
end
end
My user model
class User < ApplicationRecord
# Include default devise modules. Others available are:
# :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
has_many :posts
end
My post model
class Post < ApplicationRecord
belongs_to :user
end
i have also added user_id to user through this migration:
class AddUseridToPost < ActiveRecord::Migration[5.0]
def change
add_column :posts, :user_id, :integer
end
end

Answer 1

as the error says, permit the user_id as follows
def post_params
params.require(:post).permit(:tittle, :body, :user_id)
end
Or, better approach is you generate a new post for the logged_in user as in post create:
def create
#post = current_user.posts.new(post_params)
# ...other logic
end
This way, you don't need to allow user_id also, it will ensure that the params are not tampered with..

Answer 2

If you add column in your model, you should add it to your permitted params. So add :user_id in your permitted params in posts_controller:
def post_params
params.require(:post).permit(:tittle, :body, :user_id)
end