user3091905 user3091905 - 1 month ago 12
Ruby Question

NoMethodError though method has been defined

I have a Ruby On Rails weblog application and am getting a

NoMethodError in PostsController#show
issue when opening a post.
PostsController
is stored under
rails/weblog/app/controllers


I get
undefined method 'set_current_page' for #<PostsController:0x007fb162831e70>
however set_current_page is defined like so:

private
def set_current_page
@current_page = params[:page] || 1
end
end


and then used in a
before_action


before_action :set_current_page, except: [:index]
before_action :set_post, only: [:show, :edit, :update, :destroy]


Full stack trace:

activesupport (5.0.0.1) lib/active_support/callbacks.rb:382:in `block in make_lambda'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:150:in `block (2 levels) in halting_and_conditional'
actionpack (5.0.0.1) lib/abstract_controller/callbacks.rb:12:in `block (2 levels) in <module:Callbacks>'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:151:in `block in halting_and_conditional'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:454:in `block in call'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:454:in `each'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:454:in `call'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:101:in `__run_callbacks__'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:750:in `_run_process_action_callbacks'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:90:in `run_callbacks'
actionpack (5.0.0.1) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (5.0.0.1) lib/action_controller/metal/rescue.rb:20:in `process_action'
actionpack (5.0.0.1) lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
activesupport (5.0.0.1) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (5.0.0.1) lib/active_support/notifications/instrumenter.rb:21:in `instrument'
activesupport (5.0.0.1) lib/active_support/notifications.rb:164:in `instrument'
actionpack (5.0.0.1) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (5.0.0.1) lib/action_controller/metal/params_wrapper.rb:248:in `process_action'
activerecord (5.0.0.1) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (5.0.0.1) lib/abstract_controller/base.rb:126:in `process'
actionview (5.0.0.1) lib/action_view/rendering.rb:30:in `process'
actionpack (5.0.0.1) lib/action_controller/metal.rb:190:in `dispatch'
actionpack (5.0.0.1) lib/action_controller/metal.rb:262:in `dispatch'
actionpack (5.0.0.1) lib/action_dispatch/routing/route_set.rb:50:in `dispatch'
actionpack (5.0.0.1) lib/action_dispatch/routing/route_set.rb:32:in `serve'
actionpack (5.0.0.1) lib/action_dispatch/journey/router.rb:39:in `block in serve'
actionpack (5.0.0.1) lib/action_dispatch/journey/router.rb:26:in `each'
actionpack (5.0.0.1) lib/action_dispatch/journey/router.rb:26:in `serve'
actionpack (5.0.0.1) lib/action_dispatch/routing/route_set.rb:725:in `call'
rack (2.0.1) lib/rack/etag.rb:25:in `call'
rack (2.0.1) lib/rack/conditional_get.rb:25:in `call'
rack (2.0.1) lib/rack/head.rb:12:in `call'
rack (2.0.1) lib/rack/session/abstract/id.rb:222:in `context'
rack (2.0.1) lib/rack/session/abstract/id.rb:216:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/cookies.rb:613:in `call'
activerecord (5.0.0.1) lib/active_record/migration.rb:552:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/callbacks.rb:38:in `block in call'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:97:in `__run_callbacks__'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:750:in `_run_call_callbacks'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:90:in `run_callbacks'
actionpack (5.0.0.1) lib/action_dispatch/middleware/callbacks.rb:36:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/remote_ip.rb:79:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/debug_exceptions.rb:49:in `call'
web-console (3.4.0) lib/web_console/middleware.rb:135:in `call_app'
web-console (3.4.0) lib/web_console/middleware.rb:28:in `block in call'
web-console (3.4.0) lib/web_console/middleware.rb:18:in `catch'
web-console (3.4.0) lib/web_console/middleware.rb:18:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
railties (5.0.0.1) lib/rails/rack/logger.rb:36:in `call_app'
railties (5.0.0.1) lib/rails/rack/logger.rb:24:in `block in call'
activesupport (5.0.0.1) lib/active_support/tagged_logging.rb:70:in `block in tagged'
activesupport (5.0.0.1) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (5.0.0.1) lib/active_support/tagged_logging.rb:70:in `tagged'
railties (5.0.0.1) lib/rails/rack/logger.rb:24:in `call'
sprockets-rails (3.2.0) lib/sprockets/rails/quiet_assets.rb:13:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/request_id.rb:24:in `call'
rack (2.0.1) lib/rack/method_override.rb:22:in `call'
rack (2.0.1) lib/rack/runtime.rb:22:in `call'
activesupport (5.0.0.1) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/static.rb:136:in `call'
rack (2.0.1) lib/rack/sendfile.rb:111:in `call'
railties (5.0.0.1) lib/rails/engine.rb:522:in `call'
puma (3.6.0) lib/puma/configuration.rb:225:in `call'
puma (3.6.0) lib/puma/server.rb:578:in `handle_request'
puma (3.6.0) lib/puma/server.rb:415:in `process_client'
puma (3.6.0) lib/puma/server.rb:275:in `block in run'
puma (3.6.0) lib/puma/thread_pool.rb:116:in `block in spawn_thread'


The posts_controller.rb file:

class PostsController < ApplicationController
before_action :set_current_page, except: [:index]
before_action :set_post, only: [:show, :edit, :update, :destroy]

# GET /posts
# GET /posts.json
def index
@posts = Post.paginate(page: params[:page],
per_page: params[:per_page])
.order('title, user_id')
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)
@post.user = User.find_by email: params[:email]

respond_to do |format|
if @post.save
format.html { redirect_to (post_url(@post, page: @current_page)), 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
@post.user = User.find_by email: params[:email]
respond_to do |format|
if @post.update(post_params)
format.html { redirect_to (post_url(@post, page: @current_page)), 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 }
send
end
end

# DELETE /posts/1
# DELETE /posts/1.json
def destroy
@post.destroy
respond_to do |format|
format.html { redirect_to posts_url(page: @current_page), 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

def set_current_page
@current_page = params[:page] || 1
end

# Never trust parameters from the scary internet, only allow the white list through.
def post_params
params.require(:post).permit(:title, :body, :page)
end
end
end

Answer

You have a typo in your update action - send instead of end.

This means Ruby is interpreting everything after it as part of that update method - and it is not defined outside the method.

In combination with the extra end that's been included after your list of private methods this means you have the correct number of ends so don't see a syntax error, but the class is not interpreted in the way you expect.

Comments