state_machine gem integration with rails 4

Question

I am facing a problem with usage of state_machine gem with my rails 4 app. A have a model which include a column call state as described in the provided rails tutorial http://gistflow.com/posts/679-state-machine-with-rails-basics

but when I define my state_machine as follows:

class Issue < ActiveRecord::Base
validates :title, :description, presence: true
has_many :notes

state_machine :initial => :new do
    state :new, value: 0
    state :analysed, value: 1
    state :assigned, value: 2
    state :inprogress, value: 3
    state :inreview, value: 4
    state :validation, value: 5
    state :resolved, value: 6
    state :cancelled, value: 7
    state :closed, value: 8
    state :rejected, value: 9
    state :reopened, value: 10
end

def next
    Issue.where("id > ?", self.id).first || Issue.first
end

def prev
    Issue.where("id < ?", self.id).last || Issue.last
end
end

Here is my IssueConntroller

class IssuesController < ApplicationController

before_filter :find_issue, except: [:index, :new, :create]

def index
    @issues = Issue.all
end 

def new
    @issue = Issue.new
end

def create
    @issue = Issue.new(issue_params)
    respond_to do |format|
        if @issue.save
            format.html {redirect_to @issue, :flash => { :success => "Issue succesfully created." } }
            format.json {head :no_content}
        else
            format.html {render action: 'new'}
            format.json { render json: @issue.errors, status: :unprocessable_entity }
        end

    end
end

def show
    @note = Note.new
    @note.issue_id = @issue.id
end

def edit
end

def update
    respond_to do |format|
      if @issue.update(issue_params)
        format.html { redirect_to @issue, :flash => { :success => 'Issue was successfully updated.' }}
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @issue.errors, status: :unprocessable_entity }
      end
    end
end

def destroy
    @issue.destroy

    flash[:error]= "Issue '#{@issue.title}' Deleted!"

    redirect_to issues_path 
end

private
def issue_params
    params.require(:issue).permit(:title, :description)

end

def find_issue
    @issue = Issue.find(params[:id])
end

end

I am falling into a undefined method `state_machine' for # NoMethodError in IssuesController#index. of course I have added gem 'state_machine line into my gemfile and run bundle install command. It seems like the gem is not loaded by the rails application...

Thank you for helping me out with this problem ;)

here is the trace

 activerecord (4.0.0) lib/active_record/dynamic_matchers.rb:22:in `method_missing'
app/models/issue.rb:5:in `<class:Issue>'
app/models/issue.rb:1:in `<top (required)>'
activesupport (4.0.0) lib/active_support/dependencies.rb:423:in `load'
activesupport (4.0.0) lib/active_support/dependencies.rb:423:in `block in load_file'
activesupport (4.0.0) lib/active_support/dependencies.rb:615:in `new_constants_in'
activesupport (4.0.0) lib/active_support/dependencies.rb:422:in `load_file'
activesupport (4.0.0) lib/active_support/dependencies.rb:323:in `require_or_load'
activesupport (4.0.0) lib/active_support/dependencies.rb:462:in `load_missing_constant'
activesupport (4.0.0) lib/active_support/dependencies.rb:183:in `const_missing'
activesupport (4.0.0) lib/active_support/dependencies.rb:494:in `load_missing_constant'
activesupport (4.0.0) lib/active_support/dependencies.rb:183:in `const_missing'
app/controllers/issues_controller.rb:6:in `index'
actionpack (4.0.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.0.0) lib/abstract_controller/base.rb:189:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.0.0) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (4.0.0) lib/active_support/callbacks.rb:413:in `_run__901873103026712443__process_action__callbacks'
activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.0) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.0.0) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.0.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.0.0) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
activerecord (4.0.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.0.0) lib/abstract_controller/base.rb:136:in `process'
actionpack (4.0.0) lib/abstract_controller/rendering.rb:44:in `process'
actionpack (4.0.0) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.0.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.0.0) lib/action_controller/metal.rb:231:in `block in action'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:80:in `call'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:80:in `dispatch'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:48:in `call'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:71:in `block in call'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `each'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `call'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:655:in `call'
rack (1.5.2) lib/rack/etag.rb:23:in `call'
rack (1.5.2) lib/rack/conditionalget.rb:25:in `call'
rack (1.5.2) lib/rack/head.rb:11:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/flash.rb:241:in `call'
rack (1.5.2) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.5.2) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/cookies.rb:486:in `call'
activerecord (4.0.0) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call'
activerecord (4.0.0) lib/active_record/migration.rb:369:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.0.0) lib/active_support/callbacks.rb:373:in `_run__77618213725076532__call__callbacks'
activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.0.0) li/content_length.rb:14:in `call'
rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'b/action_dispatch/middleware/static.rb:64:in `call'
railties (4.0.0) lib/rails/engine.rb:511:in `call'
railties (4.0.0) lib/rails/application.rb:97:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
rack (1.5.2) lib/rack/content_length.rb:14:in `call'
rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'

Answer 1

There is no problems in you code, try to reload SERVER after bundle , don't forget to add state:string or ìnteger since you use a value for state, to your model and of course same event like

    event :add_new do
      transition new: :analysed
    end

as a definition of state machine: is a transition form state to another

in rails c you can call some method for state machine

   Issue.first.state_name
   Issue.first.state_events
   ....

if you still have problem try to explain more :)